This amplifier is a jaw breaker from my perspective. Ok, there are some areas where you can find better. It doesn't shine with very, very efficient IEMs, and of course it won't amplify HE6. 
 
However, if you will be using it with a moderate power requiring headphone, I think that it would be very hard to find a portable amplifier better than this... at any price. 
 
What I love about it the most is the effortless, natural sound signature it has, followed by an excellent bass, superb midrange,  *very* clean sound, spacious and holographic soundstage.
 
It also has good details and natural transient response. The sound signature is a little bit on the warm side. 
 
To get all from this amplifier, you should pair it with a good DAC. Will try it with Chord Mojo soon! 
 
Small Comparison to FiiO E12A
 
 
I won’t loose too much time on this comparison. Overall I ended up preferring the Aune B1 and not by a small margin. B1 sounds considerably more natural and organic. The sound is more dynamic and decompressed on B1 (E12A sounding a little flat/dry in comparison) , with better transparency and details.
 
The bass on B1 kicks ass compared to the one on E12A, the midrange is better textured and more detailed, while the treble is smoother and more detailed in the same time on Aune.
 
 
Pros

1. Excellent bass with wonderful extension, control and punch
2. Rich and detailed midrange
3. Smooth, detailed and sparkly treble
4. Excellent vocals
5. Very natural and clean sound
6. Very spacious and natural soundstage
7. Very good transients
8. Very good imaging and instrument separation
9. Excellent price for what it offers

Cons

1. The volume knob and switches are made of plastic
2. Position of the volume knob and gain switch are not very fortunate
3. Gets quite hot if you want to use it in your pockets. If it's winter this is a pro )

     Firstly I must give a large and heartfelt thank you to both @AuneAudio for approving me a period with this and @nmatheis for organizing things in a way so that my time with this corresponded with the Carolina Canfest 5 audio meet that was being hosted in Charlotte then also I have to give thanks to @Podster for sending it to me within the correct time frame, which lately has become a rarity for most tours. So to all of you I both tip my hat and sincerely thank you. 
 
 
               
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The Opening Experience
 
    The opening experience of the B1, I’m not exactly sure if this is how it comes from the factory of if it was only for this tour.. In addition, the only thing included with said package was a small aux cable. So, for this reason I cannot justify giving any sort of unboxing experience impressions on the Aune B1.
 
            
 
 
 
 
Construction
 
    The build quality on the Aune B1 portable headphone amp. is  absolutely top notch. It’s carries an aluminum body throughout and on the back there’s either a real or faux leather that gives the B1 not just a nice grip when holding it but also a refined look as well. However a quick downside (that’s incredibly small and user dependent) is that on the back where the leatherique material is, is down the middle is an aluminum line. This is a bad thing because most of us who use a portable amp with our mobile device etc… simply rubber band them together. The issue here is with the aluminum you’re almost begging to have both your mobile and the amp. to  get scratches all over them.
    The top of the amp. holds a very responsive volume button and standard 1/16th” jack. The side holds the power button, gain switch, and class A amp. switch (which I’m not going to lie I’m not really sure what this switch did so I just left it on). The front has 2 glass windows to allow you to look into the inner circuitry which is a subtle but very nice touch that I really enjoyed. Another downside before I go onto the sound section, is that the battery life indicator is quite useless. When you press the button, at least on my unit, it never shown anything except green. This was greatly annoying for after a few hours of listening I’d check the indicator and it’d show green and a few minutes later it died; what’s the purpose of an indicator if it doesn’t indicate anything?
 
                                                                                             
 
 
Sound
 
    So how well does the newest mobile amp. offering from Aune stack up? Amazingly well is the clear answer to that, The ease it drove any headphone I put through it was incredible, from my Empire Ears Hermes to my Sennheiser HD650 it powered them incredibly and provided a sense of depth that even some (similar priced) home units can’t provide me.
    The background wasn’t completely black as my ciems still had that ever present hiss but when listening to normal resistance headphones there was no issue at all and the only thing I was presented with was a very impressive sound that provided a subtle but welcomed amount of warmth.
    On the note of warmth, the Aune B1 isn’t a flat amp. Instead it gives the music a subtle yet very nice and soft sense of warmth and musicality to it that really reminded me of a tube amp. (which the glowing led’s on the front even adds to the look of a tube amp. as well). My favorite pairing however was with my Bowers & Wilkins P7 and the Meze Headphones 99 Classic (tour). The B1 complemented the sound of those two headphones so well it made it ridiculously difficult to take them off when I had to do that adult thing called work.
 
                                                                                 
 
 
Conclusion
 
    I believe this is my shortest and quickest review (at least off the top of my head) but this is a pretty straightforward amp. The sound is very clean, powerful, controlling and possesses a slight warmth to it that adds well wanted (for me personally) musicality to the sound. The build quality is absolutely top notch and I’ve zero worries about it falling or easily breaking. I’d recommend the Aune B1 to anyone looking for an portable amp. only complement to their mobile device. It’s a great price/quality catch and will suffice even the truest of die hards.

 
Also check out my unboxing and review videos, they’re pretty awesome AND you getta put a face to the Army-Firedawg name. If this review helped you out at all please hit that thumbs up button for it really helps me out as well. Till next time my friends, stay safe.
 
 
 

This is a true Class A amp that is in a class of it's own! 
 
I have put in a good 5 hours of straight listening with the B1 with all types of music just using my Creative Aurvana 3. I used these on purpose on the high gain to see if it would make a difference as they are not the best but not the worst earphones I have. 
 
I used the high gain, and I have to say the B1 is quick, clean, powerful, and adds no coloration to the source and transfers over the source cleanly at all levels of listening, meaning it's clean and clear at low volume to full volume with 0% distortion. Some have said there is no background hiss. Well there is on high gain but it's extremely tiny and only detectable at more than 80% volume. Very very acceptable. Some have said it has a dark background, I agree 100%.  
 
What impressed me the most is how it keeps it's clarity at full volume with authority. I love that! I like to listen to some favorite songs louder than others. This is how I determine what a portable amp can or can not do. Other amps I that I have seem to struggle out or distort at higher levels. I even tested some very high end recordings from Techmaster P.E.B and they sound clean, and clear at all levels. The bass is super heavy on from this artist and the B1 controlled the bass again with authority and no distortion. I even tried to throw in some EQ to see if I can cause any distortion and that idea failed miserably. It handled the added 40 and 80hz cleanly and accurately! I am impressed again.  
 
The B1 makes me feel like I'm listening to my Asgard 2 which says a lot! I love the clarity and level of detail that it can produce. I have yet to really burn it in fully and I am already seeing this as my favorite next to my Cypherlabs and that was just out of my LG Optimus G Pro with ALAC and a line out! I can say this amp has made me end my search for a portable clean powerful amp.  
 
I am kinda scared what it can do with my other earphones and other sources!
 
Update: After some more time with the B1, I have to say that it's so very much similar sounding to my Ray Samuels P-51. The B1 having a larger current ability than the P-51 is evident in the oomp of the sound, but all else it matches the P-51 on all other aspects. That is pretty amazing considering the P-51 is/was $375.00!
 
- Update 3/11/2016: I have to say this amp is equivalent to my Cypherlabs which says a lot as that cost over $500.00 amp alone. I am impressed with this amp the more I use it. It's not just a Class A amp, it's in a class of A! It drives my Havi's well and accurately and anything else I have at it IEM wise. Again for the price you can't go wrong with this amp. It's my new best sounding, smallest amp I have. It's going to be really hard for someone to beat this at this price.

 
 
DISCLAIMER
I was provided the Aune B1 as part of a mini-tour @money4me247put together after he reviewed the B1.  I am in no way affiliated with Aune, and this is my honest opinion of the B1.  I would like to thank @money4me247 for giving me the chance to test drive the B1, and I hope my thoughts prove useful for fellow Head-Fi members as well as for Aune.

 

INTRODUCTION
Ok, so why review the Aune B1?  When I saw it announced, I wondered how the B1 wold to my Fiio gear (E12A, E12 DIY & X5).  I was also intrigued by the discrete circuitry and Class A feature.  
 
 

ABOUT ME

I'm a 43 year old father who loves music.  From electronic (Autechre, Boards of Canada) to modern/minimalist composition (John Cage, Philip Glass) to alternative rock (Flaming Lips, Radiohead) to jazz (John Coltrane and Miles Davis) to metal (Behemoth, King Diamond) to classic rock (Eagles, Rush), I listen to a wide variety of genres and artists. 
 
My portable music journey started with the venerable Sony Cassette Walkman and then progressed to portable CD players, minidisc recorders (still have my Sharp DR7), and finally on to DAPs like the Rio Karma, iRiver IHP-1xx, iPod 5.5, iPhones, and the newer crop of DAPs from Fiio and iBasso. 
 
I typically listen with IEMs from my ever-growing collection from budget to mid-fi. Less often, I grab a pair of full-size cans.  Recently, I've been listening a lot with various earbuds and IEM I have in for testing.  I do have a lot of other gear, though.  You can always check my profile for a reasonably up to date gear list. 
 
As with a lot of people my age, I've got some hearing issues.  I've got mild tinnitus and suffer from allergies, which can affect hearing in my right ear.  I'll admit it, I'm not blessed with a pair of golden ears.  That said, I've been listening to portable gear for a long time and feel confident in assessing audio gear - just wanted to be transparent up front. 
 
 
SPECS
Please refer to this LINK for official specs.
 
 
PACKAGING & ACCESSORIES
 
External packaging is a simple black & white.  I hate gaudy packaging and highly approve of the approach Aune took here!


 
 
Open the box and you see the B1 and accessories.

 
 
Here's what you get: A micro USB cable, and 3.5mm IC, and the owner's manual.  No bands and no carrying case.  Hmm...

 
 
 
BUILD & ERGONOMICS
The B1 comes in either black aluminum with black leather pads or or silver aluminum with red pads.  The tour B1 was the black model.  I'll go over the various features in pictorial fashion below.
 
The front 3.5mm input and output jacks and the volume knob.  Plugs slip in smoothly without clicking in place, but I had no problems with them coming loose.  The volume knob was disappointing, quite frankly.  It feels like cheap plastic and has no marking to let you know how far you've turned the knob.  I hope Aune rethinks this with future models and replaces it with a nice matching metal knob with an indicator line.  Despite not being up to the overall quality and aesthetics of the B1, the volume knob has very smooth movement and allowed for easy fine-grained volume adjustment.

 
 
On the back, we see the micro USB receptacle.

 
 
On the left side, we find the battery indicator LED.  You push the small, flush button, and the number of times the LED flashes indicates the charge level.  I would've preferred three or four LEDs instead of just one that flashes, but it gets the job done.  Maybe next time...

 
On the right side, we find the Power, Class A, and Gain slider switches.  As with the volume knob, these cheap, wobbly plastic sliders feel out of place on the B1.  Replacing them with metal switches would fit much better with the overall aesthetics, in my opinion.  It would also make them feel more solid as they're operated.  In particular, the Class A switch should be designed as a recessed switch, since it's not supposed to be operated when the B1 is powered on.  Very odd design choice to make this a raised slider switch.

 
 
On the top, you get two windows showing off the internals.  There are also two green LEDs that light up during operation.  I think a lot of people geek out on seeing the internals.  I know I'm going against the tide, but I personally feel like these windows, and especially the green LEDs, are yet another disjointed design feature that Aune should've left out.  Of course, your mileage may vary.

 
On the bottom are the two black leather (pleather?) pads.  I quite like the look on the back with the white lettering on the black metal and black leather pads.  Very nice, and functional, too as the pads serve to protect any surface you lay the B1 on.  No need for those little silicone feet with the B1!

 
 
How big is the B1?  Just about the same footprint as my E12A but about half again thicker.

 
 
Here's another view with the Shanling H3 thrown in for comparison.

 
 
SOUND
I’m the first to admit that describing sound isn’t an easy thing to do, so I’ll try to describe this as clearly and concisely as possible without waxing eloquent about subtle nuances that only the highly-trained ear will hear.  If you’re looking for that, there are other reviews that meet your needs.  I mainly used my HiFiMan HE400 and the relatively new VE Zen earbuds with the B1.  Volume matching with the HE400 was performed with a 1kHz test tone and the Decibel 10th iPhone app.  With all that disclaimer type stuff out of the way, here are my thoughts on the B1: 
 
VOLUME MATCHING
HE400 with 1kHz test tone @ 80dB
X5: HG 65/120
B1: HG slightly over 9 o’clock
E12A: HG 10 o’clock

B1 vs. Fiio Gear (E12A, X5) with HE400
* B1 has less bass extension and impact.
* B1 has a more mid-forward, energetic sound.
* Upper register instruments and vocals can sound a bit aggressive / piercing.
* B1 has splashier highs and isn't as crisp
* B1 has a more holographic soundstage with better instrument separation and placement
* B1 has a richer, more engaging sound that can become fatiguing more quickly
* NOTE: The Fiio gear has a distinctive "house sound" sound, so I grouped them together for comparative purposes.
 
B1 with VE Zen
The B1 drove the VE Zen marvelously on HG, striking a great balance between lushness and technicality.  I did a lot of listening with this pairing and was quite happy with the sound!
 
B1 with AKG K553 
* It's ok at lower listening levels, but going over 12 o’clock with my AKG553 gets too loud and far too splashy.  I found the K553 was a much better pairing with my Fiio gear!

Class A
* I didn’t notice a difference with either the HE400 or Zen.
 
Driving Power
* The B1's volume knob goes from 8 o’clock to just past 6 o’clock.
* I found Low Gain too powerful for sensitive IEM - barely audible at 9 o’clock, loud at 10 o’clock, and really loud at 11 o’clock.
* I got great use out of the volume knob on LG with HE400.  On HG, I wouldn’t want to go over 12 o’clock.
* NOTE: I've ben informed that the B1 has been updated with a lower Low Gain setting to better accommodate IEMs but haven't experienced this myself.
 
Channel Imbalance
* There’s a slight bit of channel imbalance at very, very low listening levels - probably won’t be an issue for anyone.
 
 
BATTERY LIFE
I found the battery life estimates Aune provides are very good.  It could go about 8-10 hours in A/B mode and 4-5 hours in A mode.
 
 
SUMMARY
The Aune B1 is an interesting amp.  It's design is a mixed bag of industrial aesthetics, durable metal, and cheap, wobbly plastic.  The volume knob and slider switches were a real let down.  While I didn't care for the windowed design, I can see where many would find this quite pleasing.  For me, the sound was a bit of a mixed bag, as well.  With the VE Zen, the synergy was just outstanding!  With HE400, it was ok but nothing special.  With K553, it was only ok at low listening levels - higher listening levels made the K553's upper end far too aggressive for my taste.
 
I'd be happy to see an updated B1 with metal slider switches and metal volume knob with a volume indicator line.  I think it'd be much easier to estimate battery life with multiple LEDs instead of one blinking LED.  And at this price point, there's really no excuse not to provide a case or pouch of some sort to protect the B1 in your bag.  I mean, really!
 
I wouldn't expect Aune to alter the sound, but I can't see the B1 or other Aune products with this mid-centric sound signature becoming a go-to device for me.
 
Thanks again to @money4me247 for giving me the opportunity to give the B1 a listen!

Aune B1
 
If you’ve ever wondered how a Class A, discrete amp would sound with your portable music rig, Aune has given you the chance with the B1.
While I’m not going to go into the details of Class A nor comparisons to other amp types (Class AB, Class D), Class A is considered the best by many. I’ve found amps in all topologies that are so good that you’d never consider or care what type they are, so I don’t necessarily prefer one type over another. The design and components are what matters most.
 
Specifications:

1. Frequency range: 10 Hz – 20 KHz ± 0,15 dB
2. THD+N: <0,0008% @ 1 KHz, 600Ω
3. Signal/noise ratio: >124 dB @ 600Ω
4. Channel separation: > 110 дБ @ 1 КГц, 600Ω
5. Output power: 25 mW @ 16Ω, 50 mW @ 32Ω, 100 mW @ 300Ω
6. Headphone impedance: 16Ω — 300Ω
7. Battery: 4000 mA/h
8. Life time: 10 hours for 20 mA, 5 hours for 40 mA
9. Size: 65 mm × 110 mm × 18 mm
10. Weight: 230 g

 
Build Quality: 

1. Quality Aluminum Chassis
2. Unique window design showcasing internals
3. Stylish Faux Leather
4. Confusing switch placement

 
The B1 is a somewhat hefty amp to carry around, about the size of a smartphone lengthwise, and about 3-4 phones wide in girth. While it may be a bit wieldy to carry around, the actual quality of the device is high. The aluminum chassis and clear window casing showing the internals of the device provides a sleek look with a sturdy feel. The faux leather along the chassis also fits the design quite well without taking away from the overall appeal.
The switches and volume knobs did take away from the build though. I found the gain switch and volume knob placement to feel unnatural when I went to adjust them. It was nothing too distracting, but I’ve also used many amps that felt much better (Fiio and Cayin come to mind).
Battery life is not the greatest. The Class A design really eats up the battery, with 5-10 hours being the norm depending on your gain setting.
 
Sound Quality:

1. Good but not great power overall.
2. Slight bass tilt, 40mA mode better
3. Neutral sound

 
The B1 has plenty of power for most applications, and it excels at powering high impedance headphones. I ended up finding out that low impedance multi driver earphones do not do well with the B1 however (Havi B3). My smartphone drove the B3 at the same power level (even in high gain), which is not something I want in a $200+ amp. Every other IEM and headphone sounded stellar however. The O2 amplifier comes to mind with the overall neutral aspect of the sound.
Compared to my Geek Out 1000 V1, I found the GO1000 to be slightly more engaging and more powerful, with a slight edge in soundstage. Treble was enhanced over the B1, but I found the B1 more pleasing.
 
Conclusion:
There is a lot to like about the B1. I would very much recommend it as a portable amp for a high impedance headphone. For a portable IEM solution, I find that there are better dac/amp combo options available at similar pricing.
 
As a fan of Aune and their past products, I applaud their effort in making a unique amp that can satisfy a lot of people.

Disclaimer:
 
1. This is an Aune B1 Canadian tour unit. The tour was organized by hakushondaimao, and many thanks for his efforts. I had the B1 for a week and as the last tour member I sent it back to hakushondaimao. This review is not a required precondition of tour participation.
 
2. I'm in no way associated with Aune.
 
3. I don't believe in burn-in. I almost always use stock cable or the cheapest one I can find and call it a day. I don't believe I can distinguish lossless formats from 320kbps mp3 in a blind test regardless of any gear used, but always use lossless where possible.
 
Gears used:
 
Source: mainly Astell & Kern Jr. Other source components include Schiit Modi 2U, Modi, and Wyrd, kindly loaned by mikoss.
Amp: ALO Rx (newer one for IEM).
Amp/Dac: Schiit Fulla, Audioquest Dragonfly 1.2.
Headphones/Earphones: TH900, HE400S, UERM
 
Notes:
 
1. Average usage was 2 hours a day at 20mA mode.
2. Most listening was done on-the-go with UERM. TH900 and HE400S were used occasionally. My UERM might be an outlier: it's slightly bassy, compared with say Noble 4.
 
Hardware:
- Runs very warm on 40mA mode.
- A bit too big for me. I have small hands.
- Nice finish. Button layouts are just right. Quite an eye-catcher.
- Volume pot prone to rubbing.
- Tons of power. As long as one doesn't throw an HE6 to it, there should be no big issue in terms of volume.
- The downside of the above one is that even at low gain, low-z-high-efficiency headphones/earphones don't have much volume range. I put the Jr+B1 stack into my bag and the volume pot was accidently touched ----> huge increase/decrease of volume. Quite a bit of hassle.
 
Sound:
- Overall, quite thick, not overly so. Unavoidable solid state grain. No glaring. Notes have good body. Plenty of driving power, but not brutal. Not an aggressive sound signature.
- A minor, but apparent bass boost.  It doesn't add quality to bass, only quantity. In other words, things just get louder, but no significant improvements in definition. Depending on personal tastes, B1 lies on the boarder between neutral to fun. In no way offensive, and occasionally can make things fun. However, people who seek a strict neutral sounding portable amp should avoid B1.
- Smeared lowest/highest ends, particularly evident with UERM. I strongly suspect this a result of impedance mismatch. The output impedance of B1 may be over 5 ohm. If this was true, it's the biggest downside for me.
- Ultimately 2D soundstage. Good width but not much depth. 
- Outstanding instrument separation to the extent that it might be distracting. An excellent trait in my book. My personal favourite trait of B1.
- Hot switching between 20mA and 40mA modes made no major difference for me. 
- Higher volume levels may produce distortions and clicks.
 
Verdict:
- Maybe not a good match with my low-z-high-efficiency cans and IEMs. If I had something like HD650 in my hand, I would expect a lot of improvements.
- Slightly bassy for me.
- Considering most portable transducers are low-z-high-efficiency, B1 may be better considered as an around-home-kind portable amp.

 
Vorwort: Portable Kopfhörerverstärker sind in den letzten Jahren zu einem neuen Phänomen im Bereich der HiFi bzw. Kopfhörercommunity geworden. Kaum ein renommiertes Unternehmen hat es sich nehmen lassen, einen eigenen portablen Kopfhörerverstärker auf den Markt zu bringen. Als Beispiele dienen hier Sony mir Ihrer PHA Serie oder zuletzt Oppo mit dem hervorragenden "HA-2", der allerdings gleichzeitig auch ein DAC ist (aber auch einzeln nur als Kopfhörerverstärker per Line-In funktioniert).

Nun stößt auch die chinesische Audio Firma "AUNE" auf diesen Markt vor. Wir nehmen im nachfolgenden Test den "AUNE B1" etwas genauer unter die Lupe und vergleichen ihn mit seinen aktuellen Konkurrenten. 

Beim B1 handelt es sich um einen Class A Amplifier. Die meisten werden sich jetzt bereits fragen, ob ich mich hier am falschen Buchstaben bedient habe. Dies kann ich getrost verneinen, denn der B1 agiert tatsächlich als Class A Amplifier und bietet dadurch auf dem Papier eine extrem geringe Verzerrung im Nulldurchgangsbereich und eine erhöhte Linearität im Vergleich zu anderen Verstärker Klassen. Den großen Nachteil von Class A Verstärkern, dass diese im Betrieb sehr warm werden können, habe ich beim B1 nicht feststellen können. Ohne Frage, der B1 erreicht eine gewisse Wärme unter voller Last, allerdings ist diese zu keiner Zeit störend oder sehr auffällig.

Design:  Der B1 steht in zwei farblich unterschiedlichen Varianten zur Auswahl. Da wäre zum einen die klassische schwarze Variante mit schwarzen Kunstleder Streifen auf der Rückseite und den 2 Sichtfenstern (die Einblick auf die Platine gewähren) auf der Frontseite. Als zweite Variante gibt es ein Design in Silber mit roten Kunstlederstreifen auf der Rückseite. Das CNC-gefräste Chassis besteht bei beiden Varianten aus 100 % Aluminium und hinterlässt einen sehr wertigen Eindruck. Die Entscheidung, dem Nutzer einen Blick in das innere des Kopfhörerverstärkers zu gewährleisten, empfinde ich als elegant und zugleich technisch ansprechend gelöst. Kleine Schwächen zeigen sich allerdings beim Drehknopf für die Lautstärke. Warum hier nur auf Plastik und damit verbunden einer geringeren Wertigkeit gesetzt wurde, kann ich nicht nachvollziehen. Außerdem fehlt mir persönlich eine Markierung auf dem Drehknopf, die anzeigt in welcher Stellung sich besagter Lautstärkeregler befindet.

Klang: Für den ersten Test haben wir ein iPhone 5s mit dem Oppo-HA2 (hier nur als DAC) zusammen mit dem Aune B1 betrieben. Als Kopfhörer diente ein Beyerdynamic DT 770 Pro (80 Ohm Version). Die Musik kam dabei kraftvoll aus dem B1, wurde klar und überaus detailliert wiedergegeben. Im direkten Vergleich zum Kopfhörerausgang des iPhone konnte der B1 mit einer größeren Bühne und besserer Instrumentenseparation punkten. 

Ohne den Oppo HA-2 als DAC am iPhone sah das Ergebnis dann vergleichbar aus. Da der interne DAC-Chip des iPhones nicht mit den DAC vom Oppo HA-2 mithalten kann, fällt das Ergebnis etwas „flacher“ und weniger lebendig aus. Nichtsdestotrotz klang der B1 am iPhone besser als der direkte Kopfhörerausgang dessen.

Für den zweiten Test haben wir den B1 dann am IBasso DX90 mittels Line-Out verwendet. Als Kopfhörer wurde ein Beyerdynamic T1 benutzt. Mit dem T1 stößt der DX90 schon etwas an seine Leistungsgrenzen, zumindest wenn es um mein persönliches Lautstärkeempfinden geht. Dazu muss erwähnt sein, dass ich persönlich Musik gerne etwas lauter als die Norm höre. In Kombination mit dem Aune B1 konnte der DX90 dann mit dem T1 überzeugen. Den B1 hatten wir hierbei auf der höheren Gain-Einstellung. Etwas mehr Power hätte ich mir persönlich noch gewünscht, für die meisten Hörer wird die erreichte Lautstärke aber wohl vollkommen ausreichen. Als Konkurrent für den B1 sehe ich hier den Cayin C5, der einfach noch mehr Dampf macht und die Leistungsreserven aus so ziemlich allen Kopfhörern rausholt.

Zuletzt haben wir den B1 dann noch am iPod Touch 5G verwendet. Als Kopfhörer dienten hierbei die Stagediver SD2 von „InEars“. Da diese In Ear Monitore sehr effizient arbeiten, reichte hier die niedrigste Gain-Stellung am B1 aus. Leider sind uns hierbei in den niedrigsten Lautstärken geringe Kanalschwankungen aufgefallen. Sobald man die Lautstärke etwas anhebt, verschwinden diese allerdings recht schnell. Aber gerade für IEM’s könnte das bei manchen Hörern für gewisse Enttäuschung sorgen. Nichtsdestotrotz konnte der B1 auch in Kombination mit dem Stagediver SD2 punkten. Die Bühne wirkte geringfügig weiter und dreidimensionaler. Veränderungen am Frequenzverlauf konnte ich in keinen der 3 Tests feststellen. 

Fazit: Aune ist mit dem B1 ein potenter Kopfhörerverstärker gelungen. Die geringen angesprochenen Schwächen im Design kann man verzeihen wenn man einen leistungsstarken Kopfhörerverstärker mit genug Leistung für die meisten Kopfhörer sucht. Sehr leistungshungrige Kopfhörer würde ich allerdings eher mit dem Cayin C5 verwenden, da dieser doch noch das letzte bisschen Potential aus den Kopfhörern kitzelt. Im Vergleich zu den Kopfhörerverstärkern aus dem Hause Fiio braucht sich der B1 allerdings nicht zu verstecken. Hier würde ich den B1 sogar klar favorisieren, da mir die Bühnendarstellung sowie der relativ neutrale Frequenzverlauf besser gefallen. Am Oppo HA-2 kommt er nicht vorbei, allerdings wäre ein Vergleich hier auch nicht fair, da der Oppo HA-2 neben dem sehr guten Kopfhörerverstärker auch noch einen großartigen DAC an Bord hat und somit als Gesamtkonzept für mich als jemand mit iPod Touch 5G oder iPhone 5S deutlich interessanter ist. Für alle anderen Anwendungen ist der B1 von Aune aber ein überaus geeigneter Kopfhörerverstärker.

 

Intro: I have spent adequate amounts of time with the B1, mainly after working so it was something I used to relax. I have an AK100ii I compared it with with a JH13. The Cayin C5 is having a few problems right now so I felt that it was not best to test it at this time.
 

Packaging and Item finish

 



 



 

Upon opening the package, you get a charger, 3.5mm interconnect, paperwork and the device itself. The device itself has a solid weight on it but with the surprise of the plastic volume knob. Another issue with the volume knob might be accidentally turning it when it's in your pocket which can be a real issue. It has a good feel when you turn it but I feel like plastic is still not the best choice for it.

 

It has a similar form factor with the Cayin C5 and it fits pretty well with the AK100ii as shown below.

 

 



 



 




The lighting is nice and pleasant but can be a bit annoying if you use it at night The alignment of certain setups also determines if the lighted parts will show or not, in my case it was covered by the AK100ii.

 

 

Sound Quality

 



AK100ii+Cayin C5+JH13

 



The stack with a JDS labs mini interconnect.

 

The sound reminds me of the AK100ii amplifier with subtle differences. There is no hiss coming out of these headphones and no noises in the volume knob. Bass response did improve a bit with the JH13 giving more emphasis on the bass than it usually does with treble. The AK100ii on the other hand gives slightly more emphasis on the treble which can make the JH13 a bit too piercing in the ears. I've also noticed that instrument separation with the JH13 is slightly less compared to my typical setup. Mids are just as good as the AK100ii to my ears. I did not hear any difference with the Class A mode with my IEM but YMMV.

 

 

 



The Aune B1 on a Pelican 1020 micro case. It is a snug fit.

 

Conclusion/Thoughts on Value
I wanted to keep this short and sweet and as objective as I can. Comparing A and B and recording what I perceived. I have pondered upon what audience they were trying to target with this and I think it does very well with IEMs and portable headphones. Since I already own the Cayin C5, I won't be buying this but the build quality and sound quality itself makes me give it a double take. I remember disliking the E12 a while back because it felt too bright and thin and this wasn't like this at all. I think this is one of those things that would pair well with any transport with a sub-par amplifier assuming you are not burdened with its size. What I could think of would be a FiiO X1 or DX50 which I think would go well with this. Value-wise, it's a bit higher than the competition with the FiiO E12, FiiO E11K and the Cayin C5 but you are getting the Class A feature which you do not see in any of these units. Having owned the C5 and E12, I think the B1 can hold its place pretty well. It's rated at slightly less compared to the C5 and E12 @ 500mW@32 ohms compared to the competition at 800mW@32 ohms. The advantage of this is that the volume knob is not too "sensitive" as I use my JH13 with the C5 at 3'o-clock to get to listenable levels. 

Let's ruin the surprise:
 
I'm buying an Aune B1 the moment the nice folks at Aune Audio show up at my door demanding their demo unit back. I can't stop playing it and there's one huge reason: The Aune B1, against all expectations, makes my Audeze LCD-X headphones sound better...way better...when I'm using my Astell and Kern AK-100 Mark II DAP and it rivals the sound from my much more expensive Fostex HP-A8C DAC/amp streaming Tidal or accessing ITunes.
 
I'm not kidding. I had just started using the touring B1 and the LCD-Xs by playing a Norah Jones tune that has no sound in the left channel for the first few bars and I mistakenly thought "oh crap" the left channel is dead so something must be broken somewhere. I mean there was nothing in the left channel. There was no noise - no hiss - no nothing. It was like the left channel didn't exist. It wasn't like it was absent. It was like it wasn't there and never had been there and suddenly eight bars or so into the music the left channel emerged out of a intergalactic black hole and burst into glorious sound.
 
I was stunned.
 
And, if this wasn't enough now the sound out of both channels was driving my LCD-Xs into new realms of detail and punch. That did it. I went to search for my chargecard!
 
You don't have to read any farther. If you've got big expensive headphones and a $200 investment isn't a big deal then go to Aune (sold here in Canada by Grant Fidelity) and buy the B1.
 
BTW here's the standard disclaimer around nobody is paying me for my opinions (although as a former newspaper and magazine editor and writer I'm still available. I write for several of my own blogs on a variety of subjects.) and I would like to thank Aune for supplying the B1 which is on tour.
 
It might help to know I'm 66 and my wife gives me my allowance for cleaning the house once a month plus there's my pension cheque so I'm self-supporting and picky about what I buy.  I got into this audio thing at the beginning of the year and I now own way more headphones and IEMs than your average big band. I've got DACS upstairs and down and everything is streaming including TIDAL through Apple's Airplay system. I'm a very happy camper although yoga four times a week helps.
 
For those of you still with me, there are a couple of things you should know now about the B1,
 
First the B1 tends to overpower my in-ear monitors. I wouldn't have thought such was possible and when I read another reviewer who made a similar statement I thought he was delusional. I mean how can an amp be too powerful? Well it can. The B1 on its lowest power setting still sounds too aggressive in my Shure 535s. The bass hits too hard. Same with the Titan !s and the rest. Any of the higher pitch percussive notes came out way too sharp. It can hurt.
 
Yes you can turn down the gain but this isn't an amp that you'd want to exclusively drive your in-ear monitors. (Get Cypher Labs Picollo for your IEMs. It too uses discrete parts like the B1 which some claim make for a more elegant sound. I tend to believe them.) On the other hand, if you like a lot of music in your ears this might be your ticket to sonic amazement at least until your hearing fails. The Random Access Memory cut of Get Lucky is pretty intense using in-ears. The Audezes handle the musical assault with easy. This could be an age thing as in me being older and you not so much?
 
My Momentum on-ears handle the sound output of the B1 pretty well too but again when I switch back to my 535s even turning down the volume doesn't make this a soothing experience. It's aggressive as heck and where Bob Marley and Wailers sound like they're screaming in the IEM, they sound much better in the Audezes or the Momenums.....if you're on the low gain setting. On high gain - Class A setting you can feel the Audezes kicking into high gear and the difference is shocking, even exhilarating.
 
I've had the Audezes since the beginning of the year and I've read every review I could find about all the high-end headphones out there and while I loved the sound the LCD-X produces there was something missing for me when it came to using them with a DAP. The missing bit was that intangible "wow" factor that I can hear in the Momentum on-ears or the 535s when using the DAP and a small amp. It's subtle for sure but sitting on the couch with the AK-100 Mark II driving my Cypher Labs Picollo amp with the 535s remains one of the best musical experiences I've ever had.
 
When I swapped out the LCD-X the sound was still perfect but...
 
Remember that song from the 60s by the Lovin Spoonful called Did You Ever Have To Make Up Your Mind? One of the lines goes: Sometimes you really dig a girl the moment you kiss her and then you get distracted by her older sister!
 
That was my experience. On their own the LCD-X were very kissable headphones. They did everything just right. But then I plugged in the B1 and boy was I distracted by this older sister who was much more muscular and aggressive. 
 
So what's happening?
 
The B1 is a class A amplifier. So what's class A? 
 
In the Amateur (Ham) Radio world where I come from we use a lot of different kinds of amplifiers. Amplifiers...well amplify. They can boost audio signals or radio frequency signals and for the most part it's all the same thing. They shouldn't take anything away or add anything as they just amplify the signal.
 
What's different about a Class A amp is they are relatively simple devices. There's often not a lot of parts and a Class A amp is on (that is to say amplifying) all the time. That's one of the reasons Class A amps tend to run warm. There's no cooling off time. This 100 per cent demand on the circuit also means there's a higher demand on the power supply no matter if it's battery powered or runs off 110-volt AC. BTW the kind of warm I'm talking about is warm like a puppy or kitten warm. Not warm like an oven or hair dryer warm. You don't want hot when it comes to your electronics.
 
There are other kinds of amps. A Class B amp uses what's called a push-pull configuration of tubes or solid state devices so that only one half of the amp is working at any one time while the other half is turned off and thus cooling. The two parts of the amp switch back and forth many times a second making them more efficient than class A amps and are often used in audio circuits. There are other classes of amps out there like Class A/B and for those interested I'd suggest the great Google for answers.
 
Right now it comes down to do we want efficiency or do want power? 
 
As far as I'm concerned, especially when driving the LCD-Xs I want power and the B1 delivers.
 
It's like this: Let's pretend you're a Navy pilot. You're parked on your aircraft carrier and you get the go-ahead to take off. You don't release the brakes and then slowly bring the engine up to speed. You know what will happen. By the time you roll up to the edge of flight deck you won't have gained sufficient speed to actually take off. So that's not how to takeoff from the flight deck of a carrier. The right way is when you get the okay to go, you make certain you're brakes are on tight (might even be a restraining cable...I don't know as I've never been in the Navy) and you increase the power of your engine to military power of 110 per cent. Then with every rivet in the aircraft trying to rip itself out of its socket, the engine screaming, your heart in your mouth, you release the brake and the aircraft leaps into the air.
 
Hardly what we'd call efficient but it sure is powerful.
 
And so we have the Aune B1. Turn it on and it's on at 100 per cent. Likely doesn't matter whether you're actually listening to anything or not. The B1 is running full out and thus warming itself in the process. It's going to be a nice unit to place in an inside a jacket pocket on a snowy winter day in Canada. And remember, I'm saying warm here and not hot. Again hot you do not want in your electronics. Warm is okay especially when you know you're running a Class A amp.
 
So if this isn't enough to make you giddy with joy there's the price. At $199 the B1 isn't inexpensive, it's downright cheap. But cheap isn't a bargain if the sound isn't there. There are a lot of other guys out there who have reviewed the heck out of the B1 and I think I'm safe in saying they all have said they liked the sound of the B1. Some even raved!
 
A few carped about things I don't find important like whether the volume knob is metal or plastic or how cheap the fake leather inserts seemed to them. I actually thought they looked pretty good but what I think about the cosmetics is irrelevant IMHO. Your mileage may vary.
 
Coming from the Ham Radio world where some of things I buy come in a bag and you solder them onto a circuit board and connect them to circuits using alligator clips and there's no case or fancy anything I couldn't care less about the aesthetics of the B1. What makes a buying difference for me is whether or not the thing enhances my listening experience and the B1 passes that test with flying colours. Having said that the B1 might have come with a few accessories. As it is you get the B1, a USB cable, a business card, a mini quick guide and a four-inch stereo plug. I mean you don't need anything else but I'm getting spoiled by other manufacturers adding cases, higher-end plugs even key chains. I know I'm being very shallow here.
 
But when it comes to sound, I spent hours and hours swapping out headphones with the AK-100 Mark II supplying the music to the B1. I also compared the B1 to the Cypher Labs Picollo amp and even the Fiio E-11 which was my first purchase a couple of years ago. (I use the E-11 to listen to Netflicks out of my IPad. Makes a big positive difference to the sound quality of the movies.)
 
In general here's what I found:
 
The B1 as I said is super quiet. I couldn't hear any hiss or with any of my IEMs or headphones. I couldn't even hear a noise floor or anything else. It was almost like somebody had added a squelch control. 
 
Now a couple of reviewers have said they could hear a bit of channel imbalance but I couldn't. Almost everyone who has reviewed the B1 agrees it's loud and many agree it's too loud with IEM but I just read a post that said Aune is going to turn down the gain a bit on the lower gain setting. That would be a very good thing to do.
 
You see the B1 has two controls that affect the amount of amplification it can deliver. The first is just that: a gain control that switches the output stage from 20MWs of power to 40MWs (which has a big effect on battery life) and a current control whose markings suggest it switches in or out the Class A amplifier. Not sure if this is exactly what is happen as we may have lost something in translation but let's look at it this way. When using the LCD-Xs I turn everything on and my hair bursts into flame and when using the IEM I turn everything off. Clear enough?
 
Aune has warnings all over the place about not switching the gain controls whenever you're listen to music so as to not damage sensitive IEM or headphones. I did by accident and lived to tell the tale but not recommended.
 
Back to the sound...the B1, because it's always on, doesn't bog down under big musical demands. Bob Marley and The Wailers Legend album is one of my favourites for testing equipment as the music is very demanding and in your face. The B1 - Audeze combination is now the best musical experience I've ever had when it comes to Bob and the boys. Bass, mids and highs don't compete for the available wattage. There's plenty enough power for all and the sound can be called warmish without being overly coloured. It's a pleasing sound and might even be considered more listenable than the output from the Fostex DAC/amp which is a bit more sophisticated and slightly more sedate and colder.
 
Some audio engineer out there will understand when I say the B!-Audeze combo makes the music sound snappier. it's almost as if the music is coming out at a faster speed. Now I know that's not possible but the combo is hard-hitting and while realistic it's pitched just a little more aggressively than anything else I own. 
 
So what this means is when I'm listening to Lucinda Williams I can hear her breathing hotly in my ear with the B1-Audeze combo. With anything else in the house...not so much and I like to hear Lucinda that close to me...I really do The Picollo amp sounds more polished and laid back and anybody would be thrilled with the Picollo but just don't do an A - B comparison with somebody singing their lungs out as while the Picollo will entertain, the B1 will astonish. (The Fiio E11 isn't in the same league but is musically very sound and works with the IPad as I said before.)
 
One of my favourite Canadian groups The Cowboy Junkies (There's a great story here about how sister Margo Timmins had never sung professionally before when her brothers asked her to be the singer in their new band. Her haunting vocals changed the Canadian music scene back in 1986 and continues to thrill audiences today. Listen to the first song on the group's second album The Trinity Session recorded in 1987 at Toronto's old downtown Church of the Holy Trinity. Using one microphone suspended above them, you can hear the rush of the amplifiers as their auto gain settings picked up the ambient noise of the old wooden Toronto church just as Margo (who in the 1990s was named one of the 50 most beautiful people in the world by People Magazine) begins to sing. Turn it up just a little more for the full effect. Ageless.
 
Now size can be an issue. The B1 is just a little bigger than the AK-100 Mark II. It's not too big but you won't be carrying the combo around in your pocket. Now normally I walk around with the AK-100 Mark II with the 535's plugged in without an external amp or with the smaller Picollo amp and I'm perfectly happy. But the B1 is for use when I'm using the Audeze's and trust me, I'm not going outside with the LCD-Xs on my head. There's a limit to how geeky even I will be seen in public and you're talking to a guy who occasionally wears a baseball cap with his Amateur Radio callsign embossed on it. 
 
Since I'm using the B1 almost exclusively at home with the AK-100 Mark II and the Audezes size doesn't matter but...
 
Then there's battery life issue. Since the B1 is always running at Class A power the battery drains in as little as four hours on maximum gain out and about 10 hours according to Aune at minimum gain settings. Four hours if you're walking around with the B1 connected to a decent DAP isn't a lot of time but there is solution. You can add an external battery!
 
Since the B1 is charged via the USB connection to a computer (and in fact doesn't include an external power supply) it makes sense that external batteries like the Mophie external batteries made for powering an IPhone or IPod should work just fine and they do. I purposely left the B1 on as I typed this review and the battery died after four or so hours of high-gain power listening. I added an external 8000mah Comwave Power battery and the music keeps playing. 
 
But the setup weighs one pound six ounces! That's not pocketable but it would be fine in small backpack. Now since I'm using the setup while sitting outside on the deck I don't care but for some it might be an issue. (One of my new external batteries - Xtorm bought while on a trip to Switzerland - includes a solar panel so in theory I could sit out on the deck on a sunny day and never run out of power.)
 
For me, when it comes down to sound verses weight, sound wins hands down and the B1 has got the sound and the power and the fury to drive big headphones (even those that people say are easy to drive) into higher realms of musical excellence. 
 
Don't believe me. Listen for yourself. Like Sade is singing right now: This is "No Ordinary Love" and Aune: the cheque is in the mail.

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DISCLAIMER
I received this B1 unit for a two-week period in order to provide Aune with some feedback on it in the form of a review. Details of the opportunity can be found here in the original thread:
http://www.head-fi.org/t/765999/aune-b1-headphone-amp-worldwide-review-tour-reviewers-wanted

I want to thank Aune for giving me the opportunity to be a part of this program, and I look forward to seeing how future products will turn out from the feedback provided!



Note #1:
I'm experimenting with a different formatting style while writing this review. Long reviews when viewed on the mobile website tend to look like a giant essay and it's hard to pick a section of the review that's relevant to you, so I'm putting the different sections in spoiler tags. If you guys could provide some feedback on it, I would greatly appreciate it and it would help me make better-formatted reviews in the future. Thank you in advance! : )

Note #2:
Since Head-Fi takes the average of the detailed ratings on the left, I'll list what I rated the B1:

• Audio Quality: 4/5
• Design: 3/5
• Quality: 3.5/5
• Value: 4/5

Overall: 3.625/5, rounded down to 3.5/5 stars



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Video Review

[video]https://www.youtube.com/watch?v=84b0R8Ofxrg[/video]




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Originally running a well-known audio DIY forum in China, the company behind the Aune brand has managed to turn itself into a fairly reputable audio brand in recent years, producing mainly PC based desktop Hi-Fi gears. As far as I know, the B1 portable amp that is going to be reviewed here is the company’s first foray into the portable amp market – and not a run-of-the-mill design at that. Not only does it has a fully discrete design, it is also running at Class A configuration. That sound promising on paper, but does it deliver?
 

 
Spec
Recommended Headphone Impedance: 16~300ohm
Size: 65 x 110 x 18mm
Weight: 230g
Typical THD: Less than 0.0008% @ 1 kHz, 600 ohm / -0dB
SNR: More than 124dB @ 600 ohm
Frequency Response: 10Hz ~ 20kHz, +/- 0.15dB
Crosstalk: Less than 110dB @ 1kHz, 600 ohm
Power (Class A): 25mW @ 16 ohm, 50mW @ 32 ohm, 100mW @ 300 ohm
Gain: +5dB / +15dB
Dual Quiescent Current: 20mA / 40mA
 

 

 
Build Quality
To say B1 is ‘well built’ is almost an understatement – it is drop-dead-gorgeous! The aluminium housing is very well machined, smooth to the touch without any sharp corner. Two transparent windows in the belly allow you to peek inside the amp circuit and two faux leather strips on the top that not only look good, but also serves as a cushion for any device you want to strap onto the B1.
 
If there is any real complaint that I have, I’ll say the volume knob is a bit too low profiled / oddly shaped, making it harder to adjust volume, especially when there is two 3.5mm plug next to it. Last but not least – and not really a complaint here but more of a suggestion – as Aune warns that the current switch must not be used when B1 is turned on, I’ll think a more logical choice will be to make the switch even more recessed than it is now so it won’t get accidentally switched by any chance.
 
Battery Life
Aune quotes that B1 has a 10hours play time running on 20mA mode and half that with 40mA mode. I actually get a bit less, probably around 3~4 hours in 40mA, though it really depends on the load as well as the volume. Suffice to say, the battery life isn’t exactly great. Given it is a Class A amp that isn’t known for power efficiency, I guess that much is expected.
 

 

 
Gain, Hiss and EMI
B1 comes with two gain settings: +5db and +15dB. Personally, I’ll think it would have been better with +3dB and +12dB, as the current setting might be too high for sensitive headphone and IEM, getting too loud (or even worst, channel imbalance) with just a small turn of the volume knob. I will even consider a zero or negative gain setting being helpful for those with really sensitive custom IEM.
 
There is almost no hiss to speak of. There is in fact almost no ‘click and pop’ during start up as well. B1 is very well behaved in those regard. There is however some EMI issue. Cell phone interference can be picked up in close proximity, though not particularly loud and therefore not a serious concern.
 
Tech Prelude
So what is Class A - and if it is that good, why didn’t we see more of it? To put it simple: music is in wave form, swing from one end to another and back for a whole 360 degree. A Class A amp is a device that continuously operates the whole 360 degree non-stop. In the process it usually will waste a lot of power and generate a lot of heat, though it is also considered to be better sounding by many. Most of the amp (and mainly the opamp used) in the market however are in Class A-B configuration, where only half the components are active. The active half is where the signal is, and the inactive half only switches on when the signal arrives. It is far more efficient than Class A, but has its own problems - namely more distortion as components are switched on and off all the time and signal gets distorted when traveling from one end to the other. But at the end, Class A-B is usually the choice for portable gears due to practicality, as the distortion really isn’t bad enough to outweigh the benefit of less heat and much longer battery life.
 
Being full discrete means there is no integrated circuitry in the signal path. It is just another way of saying no opamp but rather individual discrete components (resistors, caps, transistors, etc) is used for amplification. B1 isn’t the first full discrete portable amp I have seen and this kind of implementation does require a lot of attention to detail, especially on parts matching, to show how good it is. A really well implementation can really sound exquisite, just as good as any top tier opamp based portable amp.
 

 
Sound Quality
As usually, my SQ assessment starts with an RMAA measurement, and the result is pretty good. No issue can be seen and the number match up with my reference O2 nicely, which is a very good sign. In fact, B1 outperforms O2 noticeably on stereo crosstalk, no doubt thanks to its dual-mono discrete circuitry that keeps the left and right channel further apart than what opamp usually does. However, the result on current output as well as output impedance is really less than stellar. First, the output impedance is rather high - measured and calculated to about 10 ohm, which is no good news for multi-drivers IEM. Second, current output is fairly low. Aune listed B1’s output power of 25mW @ 16ohm is quite low for a portable amp, and my measurement pretty much confirm it. In contrast, a FiiO E06 can pump out 4 times more power on the same load. One thing I noticed is that B1 @ 20mA mode begins to clip when I pushed the volume too high (regardless of gain setting) during my RMAA measurement (*with a 47ohm load). This is independent of the input volume so my guess is that it is running out of current to remain in Class A at such a high volume, as the clipping on high volume disappears once I retest it on 40mA mode. From both the prospective of SQ as well as battery life, I think easy-to-drive load probably can stay happy with 20mA mode, but anything more demanding should perform better in 40mA mode, though battery life will be cut short. Regardless, both modes don’t really have a lot of current output to speak of. In my opinion, this is very likely the inherent issue of being Class A – trying to push for higher output and you will end up with a portable heater that doesn’t run for very long; trying to keep everything reasonable and the output power will be limited, as in the case of B1. Technically speaking though, I think B1 is better suited for higher impedance headphone rather than lower one.
 

 

 
Subjectively, B1 sounds really good, as good as any top-tier portable amp I have heard. It also sounds rather clean and neutral, pretty much comparable to my reference O2 for that matter. While still very clean sounding, the mid does sound slightly more hollow in 20mA mode, giving the illusion of extra airiness and a bass kick that is stronger than it ought to be, which can be interpreted as being more powerful than the amp is capable of, though not really the case as I find the texture on the midrange, especially vocal, incomplete. Bass note, while has a good kick to it, does sound thinner than it should. Everything however snaps back to normal once switched to 40mA mode – the vocal is restored and all elements are inline again, though no more ‘extra’ airiness. But I don’t consider that a loss as B1 already has a really excellent soundstage and imaging. It makes a pair of flat sounding ER4S feel almost like surround sound, and that’s a wonder of its own and pretty much the best soundstage I have ever heard on a portable amp that doesn’t have any EQ enhancement. Despite not having a lot of power in measurement, B1 doesn’t sound like it is lacking power in 40mA mode. It is not the tightest in control, but it doesn’t sound loose either. All and all, it holds up quite well
 

Size Comparison (from left): FiiO E12DIY, Aune B1, and Leckerton Audio UHA-4
 
Sum-up
I really like B1. It is well built and it sounds great – if it isn’t for multi-driver / very low impedance headphone and IEM, I have no problem recommending it. Aune took on the challenge to manufacture a Class A full discrete portable amp and they almost able to knock it out of the ballpark. Sure, there are still a few kinks here and there – but for as good as it is, Aune really deserves some credit. It isn’t the portable amp for every occasions – but where it does work, it works really well.
 
This review is part of Aune Worldwide Review Tour:
http://www.head-fi.org/t/765999/aune-b1-headphone-amp-worldwide-review-tour-reviewers-wanted

Introduction:
I'll admit upfront that if you're expecting to read an in depth, technical review - you'll likely be disappointed. Other reviewers on this site have covered this little gadget in much more depth – in fact I'd argue they were writing a thesis on it. For those that like that sort of thing – all’s well and good - you may stop reading here.
 
For those of you still with me I'd like to take a different perspective. A short and to the point overview with a focus on what the Aune B1 was designed for - quality portable sound. 
 
What's in the box?
 
The professional black packaging foretells I was in for a treat and I wasn't disappointed. Lifting the lid reveals a minimalist but adequate set of:
 

1. A business card from Aune (complete with a lovely protective tissue paper)
2. Mini stereo 3.5 to 3.5mm connector cable (not sure of quality - looked adequate)
3. User manual/ leaflet 
4. USB to micro USB charging cable
5. The B1 amp (black “pleather” on brushed black aluminium in my case - red on silver also available)

​

 
First Impressions – look and feel
First impressions of the B1 remind me of looking at a sturdy hip flask. It has that sort of grab and hold it in your hands shape. Very retro – very chic. Instead of a screw off lid we have a plastic (albeit dense and high quality) volume knob. The comparison goes a stage further too – with recessed “hips” all the way around adding to the flask shape and providing a utilitarian function too. It protects the slide switches from accidental changes perfectly 
 
This thing is built to withstand a truck driving over it! It is absolutely solid – the sort of solidity and heft you’d you imagine a gold bar might have. No give, no twist – it just exists and the mass helps to dissipate heat? 
 
The first side has two textured "pleather" insets which give the B1 an air of quality and again plays to the retro styling beautifully. Then comes the wonderful surprise. You turn it over and there in all their glory are two small windows giving you a glimpse of this “badboy’s” internals. Immaculately soldered and perfectly symmetrical surface mounted components mirror (I’m guessing here) left and right channels and their associated power /control circuits. 

I’ve taken a magnified picture (below) to show the quality of the workmanship. Truly a delight to behold and again an indicator of things to come.
 
I flicked the power switch, hoping there was some juice in the 4,000mAh battery and was rewarded with two satisfying relay clicks. The B1 was alive and two green LEDs were now illuminating the windows. Very hypnotic – and I haven’t even listened to it yet. I love the see through panels.
In the hand the B1 is weighty – but not heavy. At 200g its not something you slip into a pyjama pocket and forget about in a hurry! However, it’s carriable in a ruck suck/bag or large overcoat pocket alongside your chosen portable source.
 
Pros: Solid, Robust, lovely retro styling, windows and pleather
Cons: No bands to hold your gadgets together, connector could have right angled ends to reduce cable distance to piggy backed gadgets
 

Gadget orientation and beauty shots:
This gallery captures the key faces of the B1. Features of note are:

1. Glass window panels
2. Pleather insets
3. Gain ( - is 5dB, + is 15dB) , Amp current (- is 20mA, + is 40mA) and power switch slider switches on one side
4. Volume, 3.5mm stereo in (from source) and 3.5mm analogue stereo out (to headphone/IEM) on top side
5. Micro USB charging port on bottom (only charges the B1 can't use it to power/recharge a USB gadget)
6. Single "dot" LED and button to indicate battery charge level (number flashes indicates state of charge- 5 is max)

 

Recessed slide switches for gain, amp power and device power on/off - picture shows windows on one face and the soft pleather inserts on the other.

Close up of the circuitry through one window. (Click for larger file)

Micro USB charging port on base of B1. This does not charge other devices - it's only  for getting the B1 powered up.Top surface has volume knob and 2 x 3.5mm stereo sockets - note: no indicator/mark on the knob to show its position - makes it difficult to know what volume setting you have reached. A simple "dot" on the top or a white line on the gnerled edge would be more than sufficient and an easy fix.
 

Close up of the slide switches and battery indicator.
 
 
 
So how did it perform ? What did I think of it?
 
Bullet point notes on usage:
 

1. B1 took about 2 hours to charge using high current charger
2. The battery usage figures seem broadly accurate at 10 hours use for low gain and 5 hrs at high
3. Recessed sockets didn't prevent use of headphone plus I tried though you might find a l low profile set that could foul.
4. Yes it got warm - but not hot. The metal case helps to lose heat and I noticed when it was close to my computer's fans it cooled really quickly as they sucked air across its surface.
5. Could do with bands to hold the B1 to the Smartphone
6. The lack of a "mark" on the volume control meant playing safe and moving the volume low each time i tested - a bit of a faff - was tempted to mark it with a little correcting fluid!

 
Bullet point notes on sound:

1. Outstanding reproduction for such a small device

1. Volume control is smooth . I tested it with full volume and max source output and no background noise or hissing.  This thing is deathly silent, even when it's ramped up. More importantly it's transparent. I mean sonically it's giving a flat response neither favoring high or low frequencies.  What does this mean ? Well, having tried it with the MDAC,  the samsung S3, the desktop computer and the samsung tablet,  what you hear it's what you put in. It's very clean.
2. The overall impression I got was that the sound from the B1 had "atmosphere" and "presence" it didn't distort, it simply made it more enjoyable.
3. I tended to prefer the settings at full gain and full power as they seemed more solid.
4. The B1 does have an effect on the sound, you get atmosphere. The music becomes fuller,  the bass more controlled.  Where it makes a difference, and that seems to depend on the source,  the music comes alive.  

 
Sound Stuff
All source tracks are streamed from TIDAL - high res audio to avoid issues of poor source quality. These were played sequentially via:

1. TIDAL> My PC (on board sound card using Realtek ALC898 codec) > NAD Viso HP50 - A/B with the B1)
2. TIDAL > Samsung S3 >NAD Viso HP50 - A/B with the B1
3. TIDAL > Sonos> Audiolab MDAC > NAD Viso HP50 - A/B with the B1

 
Track: Once upon a time in the west - Dire Straits remastered - Communique
I thought I'd found a weakness in the B1 when I could hear hissing on the track.  I double checked,  without the B1 in circuit, only to find it was on the original sound track. So much for transparency! For the record the drum rolls on this track are simply superb and tighter with the B1 in use. The snares, cymbals and vocals are separated. A foot tapping good listen. Again with the B1 in place,  the samsung S3 sounded more controlled and fuller.
 
Track: Bullet Proof Soul - Sade
This is a real test of very low infra-sound. You feel it rather than hear it.  Again the B1 held it together,  it reproduced the bass without muddying it. It was nicer to listen to the B1 for extended periods.  Great atmosphere and a real presence to the sound.
 
Track: Idle Moments - (Rudyard van Gelder 24 bit remastering)- Grant Green
Just for the sheer pleasure of listening. .I gave up A/B swapping, left the B1 on max gain and max power...and sat back to enjoy a beautifully rounded sound from sax, piano and drums on a solid sound-stage. 15 minutes of chilling!
 
Track: Young and Foolish - Bill Evans - Everybody Digs Bill Evans
Surprised how good the sound from the S3 actually was - but then when I added the B1 it tightened up - again the B1 was transparent, felt "fuller" and "more robust" - it was more controlled and offered better separation- I can describe it like "being in the same room as the artist" - a real room atmosphere. Definitely enjoyable.
 
Track: Mahler: Symphony No. 2 in C Minor - "Resurrection"  - Weiner Philharmoniker
I wanted to see how far I could push the B1 so I played a really mean trick.  Mahler is notoriously difficult to listen to. Tens  of instruments,  percussionists, volumes ranging from quiet to loudest of the loud.  An audio system assault course! And the 1st movement of symphony no. 2 - Resurrection is no exception. I wasn't expecting a lot. What I got was a surprise.  Again the B1 was transparent. The complex arrangements of cymbals,  drums,  trumpets, horns and violins were all in control and faithfully reproduced.  No,  I didn't get a huge sound-stage but then the real thing fills an entire auditorium!
 
Note: Across all these tracks the MDAC through the B1 didn't add much - perhaps a little more solid but really got too subtle for me to distinguish and by this time i was wanting to enjoy the music. They are both Class A amps and equally good to my ears. So I'd argue the B1 was transparent in this scenario.
 
 
Conclusions:
If you're looking to add some extra atmosphere to your music on the go and want to drive a decent pair of headphones the Aune B1 is worth putting onto your shortlist. It's looks alone are worth it, the Class A amp in such a robust package clinches it for me. I've enjoyed using Aune B1 over the past week. It's solid, looks a quality device and really adds something  to the sound experience. I'd recommend giving it a listen and seeing for yourself how transparent and atmospheric it is.
 
 
The listening set up:
 

Sonos played through MDAC and TIDAL played through Samsung S3 , B1 and NAD Viso HP50's.
 

1. Note: I tried my Shure 215 IEMs as another listening option and found they were easily over powered by the outputs from the B1 - not that it didn't add anything - however the quality compared with the VISO HP50s really wouldn't make it a value for money purchase. This balance would change instantly if the IEMs were in the next league / quality up - however I couldn't test those on this occasion.

 
 
B1 Specifications (as published by Aune):
 

1. Impedance: 16Ω - 300Ω
2. Size: 65 mm × 110 mm × 18 mm
3. Weight: 230 g
4. Typical THD+n: <0.0008% @ 1 KHz, 600Ω / -0dB
5. Signal/noise ratio: >124 dB @ 600Ω
6. Flatness (Frequency range): 10 Hz – 20 KHz ± 0.15 dB
7. Crosstalk (Channel separation): > 110 dB @ 1KHz  600Ω
8. Class A Output power: 25 mW @ 16Ω, 50 mW @ 32Ω, 100 mW @ 300Ω
9. Battery: 4000 mA/h
10. Battery Life (vs drain current): 10 hours @ 20 mA, 5 hours @ 40 mA

 
 
Disclaimer:
Yes, I won a freebie B1 from Aune for a trial period. No, it hasn't influenced my comments - I am being as transparent and objective as if I'd borrowed it from a pal. For the record, the freebie sample was for a trial "loan" period after which it has to be returned. Hope that covers off all the naysayers 

 

So I got this unit from Aune as a part of their worldwide review tour. This is actually the second Aune product that I got the chance to tinker with. First one being Aune T1 MKII Tube DAC/amp, which I bought a while ago and has been using ever since. If you wanna read my review on the T1 MKII, you can find it here. I like to think that both of them is like brother and sister
 
On with this review then.
 
Unboxing
 

 
One thing I like about Aune is their box presentation. Aune's products are mostly in the middle level price range, but their box looks so nice and elegant. The box alone instill the sense of 'class' to anyone who sees it. 
 

 
Open it up, and you'll find a few stuffs inside. From left to right:
- USB to micro USB cable for charging. 
- Mini stereo 3.5mm to 3.5mm interconnect cable, gold plated.
- The main unit, the B1 Headphone Amp (I will be referring it as 'B1' from here on)
- The box
- Aune's business card. The writings on it are all in Kanji (Chinese) though, so I couldn't make any sense of it except for phone numbers and e-mail addresses.
- User manual.
 

 

 
 
Now this unit is beeeaaauuuutiful!! I really love the design. They come in 2 variant/color scheme, the all black, and the silver/red like the one in the picture. Usually I like my devices all black, but I couldn't resist that beautiful silver-red combo. It's simply stunning!. Honestly, it's the most stylish portable amp I've ever seen. 
 
The design reminds me a bit of those liquor hip flasks, especially the volume knob on top. The leather side is actually the back side of the amp. The leather layer protrudes a bit, making it a soft cushion when you put it on hard surfaces, avoiding scratches and dusts to the aluminum case.
 

 
This is the front side of the amp. It got a twin window to showcase the discreet amp parts (more about this later), and two LEDs that lights up when it's powered on. 
 

 

 
The unit measures approximately 12 cm + 6 mm protruding button = 12.6 cm height, 16.5 cm wide, and 1.7mm thickness. It's about as big as an Iphone, but thicker.
 

 
On one side, there are 3 buttons, the power button, 'class A' (current gain) button, and the volume gain button. On the other side, there's a battery checker button with a small LED. Press this button, and the LED will blink to show how much battery is left. 5 blinks = full, down to 1 blinks = 10%.
 

 
On the top side, there are two jacks. The left one for audio output, the right one for line/signal input. Volume knob in the middle.
 

 
On the bottom side, there's a micro USB input for charging. 
 

 
 
Now what really make the B1 so special compared to other portable amps, are 4 things: the design, class-A amp architecture, discreet op-amp, and high current setting. The design part was already explained above, so I won't go further with that part.
 
- Amp class. You can find more info about various audio amp class in wiki and articles on the net. In short, class-A amp is an amp architecture that's both simple and has the least distortion, compared to other amp architectures/classes. The drawback of a class-A amp is that it needs constant electric current running through it, even when there's no signals to be processed. Because of this fact, there are two more drawbacks, which are: bigger power consumption, and more excess heat. The B1 gets warm after about 30 minutes of continuous use. Not dangerous hot, of course, just warm. Warmer compared to other portable amps. If you got a vintage speaker amp that's very heavy and got a big heatsink in the back, it may very well be a class-A amp. Because of the drawbacks, especially the power consumption, class-A architecture is rarely implemented in a portable amp. That's one of the thing that sets the B1 apart. It's like they're breaking through the common stereotype. Of course they got the battery to match the bigger power consumption. 
 
The warm temperature is a bit of a let down actually, especially for those who live in tropical climate like me (southeast Asia). Again, it's not too hot to touch (which would indicate something is horribly wrong with the device), just lukewarm. When used in tandem with my T1 (on my PC desk), I just point a USB fan to the B1, and it effectively countered the heat effect. 
 
- Discreet op-amp. Portable amps usually use op-amp chips, because they're less space-consuming, and more efficient. Discreet op-amp basically means they substitute an op-amp chip with a whole set of electronic circuit, pictured in the twin window of the B1. The benefit of this is that they can then fine tune each components (resistors, capacitors, etc) the way they like it, as oppose to plugging a factory-made op-amp chip, and accept whatever the result will be. This is of course debatable, whether or not the discreet op-amp implementation gives a better result than an op-amp chip, because the end results aren't fully determined by the op-amp part alone. Nevertheless, the use of discreet op-amps (1 for each channel) makes the B1 unique. 
 
- High current setting. When it's set to off, or 'low', the B1 will give out 20mA of current. When it's set to on, or 'high', the B1 will give out 40mA of current. The bigger current amount is useful when it's used to power less sensitive and low impedance headphones. This is usually the case with older generation of planar headphones, like the Hifiman HE-400 I'm using. Lacking in current in the signal output will mostly make the sound distorted, like when you turn the volume of your speaker amp too high, and the speakers start to sound unpleasant. Let's see if I can 'show' you:
 

*sorry about the noises in the left channel. I think it's the left mic's cabling. The right channel is working normally. I only found out about this when uploading to youtube, and I'm too tired to record a new one... Maybe I'll record a new one later.
** oh and that small piece of tissue paper is not part of the setup. It's there because the headphone is too big on the dummy head.
 
That dummy head got a pair of separate channel mics embedded in its ears. So the sound you're hearing is actually the sounds coming from the headphone. The recording volume was set to very low, because in reality that was quite loud. I have to set it loud, to the distorting level, to show the effect. Now of course this video can't be treated as 'this is how the B1 or the headphone sounds', because the stuffs I got there (mics, cables and connections, and ADC) aren't studio recording standard. This setup degrades the original sounds by quite a lot. I'm just trying to show how the current gain affects the sound. 
 
The video encoding seems to alter the sound a bit. This is the WAV extracted from that video: https://soundcloud.com/marcus-sudjojo/current-gain The difference is more audible in the WAV version.
 
Pay attention to the first part (current gain switched to low), the kicks were distorting. Not much, but still audible. In the second part (current gain switched to high), the kicks weren't distorting, and got tighter and more 'dense'.
 
This is also a special case, powering an inefficient and low impedance headphone with a portable amp. For portables uses, such as on-ear headphones or IEMs, the low current gain setting is more than enough, because portable stuffs are usually pretty efficient anyway.
 
Current gain is NOT a volume gain, so setting it higher does not mean you will get louder volume. The B1 already got a separate volume gain switch for that. So if you're using the B1 at the low current gain setting, and you don't hear any distortions, it's best to leave it at low setting, to preserve the battery, and make it run longer.
 
I have to be honest, with the current gain switch like that, it's a bit of a design faux pas from Aune. They explicitly state that the switch must not be flipped when the B1 is running. Problem is, with the design and position of the switch, it's very easy to flip it by mistake/accident. If you ask me, they should have implement some sort of locking mechanism, so the switch can't be flipped unless you open the lock first. Fortunately, I asked them if there are any danger if the switch is flipped accidentally while running, and they replied, there are no danger, plus the headphone plugged to it is perfectly safe.
 
One more thing to note is their long life battery. Their 4000mAh built-in battery is claimed to be able to run it continuously for 10 hours at low current gain setting, or 5 hours in high current gain setting. Of course with big battery capacity comes the counter-effect: longer charging time. I charged the B1 with my Ipad 10W wall charger, and it still took a couple of hours. The good news is, it can continue running while charging. So for example, the battery dies when you're on the road. Well, you can plug the USB charger cable to your power bank, and you can keep enjoying your music. 
 
The B1 also got a good electronic architecture that enables it to output the same stable good sounds until the battery runs out. I've encountered a few portable amps that output deteriorating sounds as the batteries are about to run out. That's not the case with the B1. I was enjoying my songs when the sounds suddenly stopped because the battery ran out, with no deteriorating sounds whatsoever.
 
Oi, enough about the technicalities, we wanna know how it actually performs....
 
Well, first I'd have to state the fact that I believe: out of the whole chain (DAC - amp - headphone/speaker), the headphone/speaker got the most margin of difference between one another. The DAC and amp got less margin of difference in that chain. So you can't, for example, buy a $1000 amp, plug a $30 headphone to it, and expect it to magically transform the headphone into a $1000 one. Different DACs and amps can, and will, alter the resulting sound to some extent, for better or worse, just in a smaller scale than different headphones will. So keep in mind that what I'm saying next is in a smaller scale.
 
I tested the B1 with 3 headphones:
- Audio Technica AD700 (without X)
- AKG Q701
- Hifiman HE-400
 

 
First impression I got when I plug the B1 to my Ipad (yeah, I'm not too crazy on portable devices) is that the B1 is dead silent. The 'silent test' is usually the first thing I test in headphone amps. Plug it to the source, with nothing playing, max out the volume knob. If there's any noise floor audible, then it's not really a good headphone amp. Well, like I said, the B1 is dead silent, or 'black' as some people prefer to call it. After the silent test, comes the actual listening test. The B1 'smoothen' out the edges in the songs. It's not a big secret that older generations of idevices (mine is the ipad 3) only got mediocre internal amp. When plugged to the B1 (via LOD), the mediocre quality of my ipad's internal amp got pointed out immediately. The songs sound as smooth as silk. There are no 'rough edges' between different frequencies and instruments. You might say it's a lot more transparent and less distorting. The frequency separation is very good. I could even hear some subtle sounds that weren't there when I plug a headphone straight to the headphone jack of the ipad. 
 
I played various songs, like Celine Dion's that's known for 'unforgiving' to bad devices (thus make a good test song). Her voice could sound very rough and sharp when played through bad devices. From Celine Dion, to U2, to Tong Li, to EDM like in the video. Every songs I tried came out so much better compared to the ipad's internal amp. Even my old (and mediocre) AD700 sounds so much better with the B1. 
 

 
 
But wait, like said above, I already got the T1, right? The T1 can output line out through the RCA jacks in the back. So of course I'd give it a go. Man, the B1 really outperforms the T1's internal amp. T1's internal amp is already quite good (that's why I'm using it daily, as my main device), but the B1 amp is really 1 level above it. Fed from the tube DAC of the T1, the B1 really performs its money worth, and beyond!! The sound I got was spacious, warm, rich, and yet smooth, with minimal rough edges. 
 
For people who are used to V-curved sound (like myself), the low frequencies will feel a bit lacking at first. It's lacking, not completely gone, though. I could still fully enjoy EDM songs with the B1. What it's lacking, it gives back in clarity and frequency separation. The high frequencies are very clear but not intrusive. The mids got more density to it.
 
Now I think I understand why Aune insists on implementing class-A architecture in the B1. To be honest, I've never encountered any portable amps that give this kind of result. If you have auditioned various portable amps, try the B1, and most probably you'll agree with me. 
 
Now if your music preferences is 'rocking it out loud', and you're looking for something that's 'head-kicking, bass-thumping, heart-pumping' kind of sounds, the B1 might not be the perfect choice for you. I'd say the B1 is more aimed for quality, not quantity. 
 

 
The 'siblings', T1 tube DAC/amp and the B1 Headphone amp. Zippo for size.

 
Disclaimer
 
I received a sample unit of the B1 portable amplifier from Aune Audio as part of a worldwide review tour. I was able to keep the unit for 10 days, during which I used it extensively. I did not have to pay for the unit; only for postage at the end of its tenure with me. The only expectation of tour participants was an unbiased review once we had given the B1 enough time for a fair evaluation. I am not affiliated with Aune in any way.
 
About Me
 
To begin, here's a little context. I’m 50 years old, and am pretty sure I have deficiencies in my hearing. In a recent, entirely non-scientific test I discovered I can’t really hear anything over about 15 kHz, with roll-of starting around 12 or 13 kHz, which is actually pretty good for someone of my vintage. I also like to crank things more than the average bear to get the volumes I desire.
 
I’ve been a music lover for decades, but am still relatively new to the MidFi/HiFi/Head-Fi game; I haven’t listened to a lot of high-end equipment, and am not an expert on the technical aspects of electronics or musical terminology. I have read a lot of reviews and threads on Head-Fi, and spend a lot of time on the site; as such I know what has been helpful to me in reviews and endeavor to provide what I consider useful insight to help others make decisions about items they might want to try or buy, or avoid.
 
I listen to a variety of music genres, in particular, Classical (mostly mid 1700s to mid/late 1800s), Jazz (late ‘50s to early 70’s), Rock and some Prog-Rock (‘70s), ‘80s New Wave/Electro, and Trip Hop/Acid Jazz (90’s into 00’s). My preferred sound signature would be characterized by a good sub-bass presence, tight mid bass, and relatively linear, detailed mids and highs. I like my music quite lush and rich, but with a good level of detail. I’m not a bass-head, am not a big fan of anything too boomy, and don’t like highs that are too intense or harsh.
 
Unboxing and First Impressions
 
As usually happens when I receive a new piece of equipment, I was excited to get the Aune B1. The unit arrived by courier from Hong Kong, so first order of business was to get the protective packaging off. Thankfully, not a big job, and in a couple of minutes I had box and protective material removed.
 

 
The B1 comes packaged in a solidly constructed, textured black cardboard box. Even before lifting the lid, one has the impression of quality and pride in this product.
 

 

 
Opening the box reveals two compartments within an intricately cut and folded corrugated cardboard inlay. In the large compartment one finds the B1 amplifier, within a thin, semi-opaque plastic sheath, and in the other, smaller compartment are the Micro USB charging cable and 20cm-long 3.5mm-to-3.5mm interconnect. Under the B1 there is a basic, folded instruction sheet, with Chinese information on one side and English on the other.
 

 
The B1 unit has a good heft to it. It has similar length and width dimensions to the Cayin C5 and Fiio E12A, but is a bit thicker (E12A = 14mm, C5= 15mm, B1 = 17mm). It is available in Black with black trim, or silver with red trim. I received a black B1.
 

 
The front of the B1 is gorgeous! Two glass windows reveal a circuit board with various chips and resistors. The effect is both hi-tech and artistic, and gives a highly unique feel. The only thing on the right side of the unit is the battery level indicator; press the button and a small light blinks: 5 times for full battery, 4 for 80%, 3 for 60%, 2 for 20% and 1 for 10%).
 

 
When the power is turned on, a small green light turns on in each window, giving off a tube-like glow. When ambient light is low, the glow from the B1 is quite mesmerizing and moody.
 

 
The back of the B1 is flat with nothing but the brand name and model number, and two strips of what looks like textured leather. The leather is slightly raised, providing a soft surface for resting the unit, or for mounting a DAP when stacking (the leather helps avoid scratching). The leather doesn’t grip too well though, so a stacked DAP will tend to slip and slide unless using double bands to hold units together.
 

 
At the top of the unit you find the volume pot, and headphone-out and line-in jacks. The volume pot is metal, with ridges for grip, sits flush (not much to catch on things in a pocket) and feels tight and solid. Turning is not difficult, but it does offer good resistance to inadvertent adjustment while on the go.
 

 
On the left side you find the power control, Class A current adjuster (20MA or 40MA), and gain switch (low gain is +5dB, high gain is +15dB).
 

 
On the bottom is the Micro USB charging plug-in.
 

 

 
The silver version of the B1 is quite attractive. The red leather back is quite striking in contrast to the silver aluminium chassis. Both colours of B1 are attractive and have a quality feel about them.
 
Listening
 
In my review I did some general listening using the Fiio X3ii as source, using a variety of over-ear headphones (Sennheiser HD650, Audio Technica ATH-R70x, and AKG K7XX). I also performed several comparisons to other portable headphone amps (Fiio X3 2^nd generation’s internal amp, Cayin C5 and Fiio E12A), using a variety of IEMs (Noble 6, T-Peos Altone 200, and Havi B3 Pro 1). Some of the equipment I used in my reviews was my own, and some was provided by 3^rd parties for review purposes.
 
General Listening
 
Listening 1: Norah Jones – Come Away With Me
ALAC > Fiio X3ii > Aune B1 > Sennheiser HD650 (Low Gain, Volume 6/10)
 

1. The B1 is rated at 16-300 ohms, and the HD650 is a 300-ohm headphone. As such, one would naturally expect this combination to be at the limit of the B1’s capabilities. At 6/10 and on low gain, volume was right where I like it (I like my Vs) and detail excellent.
2. In “Come Away With Me,” there is a lovely sound of brushed snare throughout that I find beautifully soothing; this was clear and textured. There is also a lovely, low-key guitar solo half-way through the song; this was atmospheric and high notes sparkled. Norah’s voice was full, with her characteristic airy, textured tone. The B1 dealt with both song and headphone very well. Very enjoyable.

 
Listening 2: Sade – Bullet Proof Soul (from Love Deluxe)
ALAC > Fiio X3ii > Aune B1 > Audio Technica ATH-R70x (High Gain, Volume 6/10)
 

1. The R70x is rated at 470 ohms. Of all the headphones I own, this was always going to be the ultimate test for the B1. Perhaps it was unfair to even attempt this one based on power ratings, but some manufacturers under-rate their amps so I figured I’d give it a try (as an example, the Fiio E12A is designed for IEMs and rated at 16-300 Ohms – same as the B1 – but it drives the R70x exceedingly well).
2. If you’ve read any of my other reviews, you’ll know that this is my favourite song for sub-bass, and I just love the combination of Sade’s vocal with those of her back-up singers (depending on equipment, these backing vocals sometimes don’t come through very well). The B1 dealt with all challenges very well. Volume reached more than satisfactory levels at 9/10 on low gain, and 6/10 on high (high gain sounded better; on low gain I felt there was just a touch of distortion). R70x test passed!
3. My initial listen to this track was done on the low current setting. Curious about the Class A current adjustment (have never played with any Class A equipment before), I did a little reading and learned that with high powered phones or speakers, higher current beefs up bass and extends treble. Decided to give Sade a listen again on the high setting, and found this to be the case with the B1; the effect was subtle, but highs and lows had just a bit more authority.

 
Listening 3: Duke Ellington & Johnny Hodges – Beale Street Blues (from Back To Back)
ALAC > Fiio X3ii > Aune B1 > AKG K7XX (High Gain, Volume 5/10)
 

 

1. Even though only rated at 62 ohms, the K7XX is known to have low sensitivity and is notorious for being hard to drive and requiring amplification. This track is a lolloping blues number, with sultry sax, piercing trumpet, lively backing piano, and some fun, low-key guitar and drum riffs. The K7XX is beautifully driven by the B1. All instruments are presented clearly, with great texture, balance and detail. Stereo imaging and soundstage are excellent, with good space and instrumental placement. A very pleasant listen!
2. After running the B1 on high gain for around an hour through the 3 general listening stages of this analysis, I noticed the B1 getting rather warm. I wouldn’t say it was uncomfortably hot or anything, but it was warm enough that you might notice it in a pocket. Not a bad thing in winter, but perhaps not the greatest in summer.

 
Comparisons
 
Comparison 1: Beethoven – Cello Sonata No. 3 (played by Timora Rosler and Klara Würtz)
320 kbps AAC > X3ii > Aune B1 > Noble 6 (Low Gain, Volume 2.5-3/10)
320 kbps AAC > X3ii > Noble 6 (Low Gain, Volume 65/120)
 

1. This is another favourite track for testing, with the interplay of rich tonality and range of the cello with energy and sparkle of the piano. The Noble 6 is a linear, neutral IEM, and I’ve found it doesn’t pair particularly well with overly analytical sources.
2. With the X3ii+B1 combination, this piece sounded marvellous. Sound was rich, with great body, richness and texture from the cello, and a lively, realistic tone from both left and right hands of the piano. Range on the volume pot was limited at a low volume setting of around 2.5-3/10, with little room for fine-tuning of volume.
3. With the X3ii un-amped, I had more range to play with and much finer control over volume settings. That said, sound quality at equivalent volume was less satisfying than with the B1 combination. On it’s own, the X3ii produced a less lively, less nuanced, more veiled performance. Cello was smoothed, and the piano was a bit one-dimensional. There were also touches of harshness in the treble that I could see being fatiguing in a more extended listening session.

 
Comparison 2: Steely Dan – Gaucho (from Gaucho)
ALAC > X3ii > Aune B1 > T-Peos Altone 200 (Low Gain, Volume 2.5/10)
ALAC > X3ii > Fiio E12A > T-Peos Altone 200 (Low Gain, Bass Boost off, Volume 4.5/10)
 

 

1. Another favourite test track for atmospherics and micro detail, both vocal and instrumental. The Altone 200 is often described as bright (I don’t find it overly so), and delivers good, strong bass.
2. These two amps had quite different characters. E12A had great bass quality (sub and mid), along with excellent detail and texture in mids and highs. Texture and detail of snare drum, bass, guitar, and sax were excellent. Sound stage was open and had depth.
3. B1 was more mid-forward, with more subdued bass and highs. Bass isn’t as much rolled off as recessed, while there was some roll-off in trebles. Texture of main and backing vocals, and body of sax (though a bit smoothed), were more satisfying with the B1. That said, stage seemed a bit more constricted.
4. While I enjoyed the music from both amps here, I found the E12A more extended in high and low frequencies, and B1 more mid forward. I liked the range in the volume pot for an with the E12A; this was again a bit limited with the B1, which I feel may be better suited to more demanding IEMs and cans.

 
Comparison 3: Pearl Jam – Jeremy (from Ten)
ALAC > X3ii > Aune B1 > Havi B3 Pro 1 (Low Gain, Volume 5/10)
ALAC > X3ii > Cayin C5 > Havi B3 Pro 1 (Low Gain, Bass Boost off, Volume 4/10)
 

 

1. This is a great track for comparisons, especially of male vocals and energy. The dual-dynamic Havi has an almost cult following. It is known to have a wide open sound stage relative to other budget IEMs, with good texture and extension, especially in treble (some find the bass a bit on the dry side).
2. The Cayin C5 sounded fantastic, with lovely tonality of bass, “school bell” and drums in the opening of the song. Eddy Vedder’s vocal texture was clear and throaty, dry and rasping. Electric guitars were full of energy, clear, with no muddiness. High-end was a touch harsh and fatiguing. Space and good instrumental definition in performance, staging was open and wide.
3. With the B1 bass was less prevalent, again with a more mid-forward presence. Gong sounds fuller than with C5. Vedder’s vocal, guitars and drums were clean, warmer, smoother than the C5. High end less harsh, less fatiguing than from C5. Soundstage smaller.

 
Conclusions
 
There’s a lot to like about the Aune B1. It drives powerful headphones with authority, and has a lovely mid-forward sound that is easy on the ears and suitable for long, fatigue-free listening sessions. Design is phenomenal, with great looks and a quality build and feel. If I had the power to improve anything about the B1, it would be 1) greater range on the pot for fine volume control, and 2) slightly more extension of bass and treble.
 

 
In comparisons with other popular portable amplifiers, I’d equate the B1 to the Sennheiser HD650 (contolled bass, mid-forward, clean, easy on the ears) and the Fiio E12A and Cayin C5 to the Audio Technica ATH-R70x (more natural extension of bass and treble). If you’re an HD650 type, you will really like the sound signature of the B1. If you’re more into the R70x, you’ll still enjoy it, especially for longer listening sessions.

Aune B1 portable headphone amplifier Review
 

 
Intro: Focusing on achieving high quality sound at a competitive price point while utilizing premium materials and uniquely eye-catching aesthetics, Aune is a Chinese company based in Wuhan specializing in high-end audio equipment. Founded in 2004, Aune is the brand of the largest Chinese audio technology community, http://hifidiy.net/. Aune’s current product line-up include the Aune S16 (desktop usb dac at $699), T1 Mk2 (desktop usb tube dac with a solid state amplifier at $229), the X1 Pro (portable dac/amplifier at $249), and the newly released B1 portable headphone amplifier ($199). The B1 embodies Aune’s philosophy and unique approach with its distinctive styling, emphasis on premium components, and unconventional topology for a portable headphone amplifier.
 
Tech: The B1 is a fully discrete Class A portable headphone amplifier with its main amplifying circuit comprised of individual triode components. MSRP $199.
 

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Features:

1. Pure Class A output
2. Fully discrete design with no opamps in its entire amplifying circuit

1. Adjustable Current Output Control (two settings): 40mA and 20mA of static current at 32 ohms, both operating as Class A
2. Adjustable Gain (two settings): low (5dB) and high (15dB)

 
Official Technical Parameters:

1. Impedance: 16-200R
2. Size: 65*110*18 (mm)
3. Weight: 230g
4. typ THD+n <0.0008% @ 1kHz 600RZ/ -0db
5. SNR > 124dBA @ 600RZ
6. Flatness +/- 0.15dB @ 10Hz-20kHz
7. Crosstalk < 100dB @ 1kHz 600RZ
8. CLASS A: 25mW/16R, 50mW/32R, 100mW/300R

 
Official Battery Specifications:
At 32 ohms, the B1’s 4000mA lithium battery provides for 5 hours of continuous current in the high current mode and provides 10 hours continuous current in the low current mode.
 
***Will update this review with my personal real-world battery life tests***
Design: The Aune B1 is an extremely gorgeous device with a very futuristic and gadgety look. Its styling is serious and stylish enough to draw attention and be appreciated without being too gaudy or garish. It can easily sit unobtrusively in professional settings, especially if placed with the leather side facing up. My geeky side found the view into the insides of the amplifier to be quite exciting and appealing.
 
The B1 is built with an entirely aluminum chassis bound in synthetic leather covering one side and tempered gorilla glass windows to view the discrete components of the amplifier on the other side. There are two bewitching green LED lights that shine on the circuitry of the amplifier when switched on, drawing your focus towards its premium discrete components. Both sides are well decorated and aesthetically pleasing to the eye.
 
Special attention was paid to creating a high quality chassis on the B1 with all six sides of the device finished by CNC (Computer-Numerical Control). Anodic oxidation with brushing treatment is applied to final surface with lettering applied via laser. More information about CNC here. More information about anodic oxidation here. On the window side, the name of the device is written in white above the windows with white labeling inscribed at the bottom edge. The three icons are the FCC label, WEEE symbol, and CE mark. There is the inclusion of an unique individual serial number on each device, giving it a premium touch. The leather on the other side also enhances the premium feeling of the device.
 
Viewing from the ‘front side,’ the volume knob is placed at the center top with line-in jack on the left and headphone out jack on right. The American-made conductive plastic volume potentiometer functions without any flaws, turning quite smoothly throughout its range with appropriate sense of resistance. The placement of the volume control is very thoughtful. I found it was very unlikely to accidentally adjust the volume even when taking it in and out of my pockets or carrying it in a bag. It is extremely convenient to adjust the volume while it is in your pocket without taking the device out.
 
 
One con noted about the volume pot is that its entire surface is monocolor without any indicator bar to dedicate what volume level is currently used. It is difficult to gauge what volume settings are currently applied or which volume settings are commonly used with different headphones. This can result in accidentally blasting the volume of the amplifier when switching between different headphones or different source devices. I recommend getting into the habit of just always turning down the volume knob prior to usage.
 
The bottom of the B1 has the micro-usb input for charging located closer to the left side. Left side (going from top to bottom) has a gain switch, adjustable current switch, green LED power-on indicator light, and a power on switch. The right side only has a single LED indicator light for battery/charging along with a small push button to trigger the light.
 
After pressing the button the the right side, the green battery/charging life indicator will flash a different number of times (1-5) to indicate the percentage of battery life remaining. While charging, the indicator light will continuously blink. Upon reaching full charge, the indicator light will be steadily on. Do note that pressing the button while charging does not do anything.
 
 
I do believe that you will not get any additional battery saving with no music playing or lower volume level on your source since the B1 amplifier will supplies a steady continuous current at all times when it is on. I did find that the battery life per current mode seemed to average pretty consistent times quite close to the official estimates. I found it has difficult to catch exactly how long it takes for the battery life to fully charge in my tests, but I estimated that it takes at most 4 hours. In real-world usage, I do not always actively check the battery life, so the device does sometimes suddenly run out of power on me.
 
My suggestion for improvement on the battery life/charging indicator would be offering another color (such as red) to indicate when the battery life is extremely low. The inclusion of a red color can also be used to indicate charging instead of the current blinking green LED. This would make it much more noticeable when the device becomes fully charged or low on battery with the obvious color change.
 
Accessories: A bit lacking. Comes with a 24 inch total length usb to micro usb cable for charging and a 3.5mm-to-3.5mm cable with straight plugs measuring 6.5 inches when plugged in. Below I list the items I feel needs to be bundled as well as items that would be nice to have.
 
Things NOT currently included, but I think should definitely be included:

1. Short right-angle cable (3.5mm to 3.5mm) for portable usage
2. x2 rubber bands for stacking purposes
3. Longer straight-angle cable (3.5mm to 3.5mm) for desktop usage

Things NOT currently included, but would be nice additions (not as necessary):

1. Wall charger
2. Some type of carrying case

 
I personally found (for my needs) I would need to use two additional 3rd party 3.5mm to 3.5mm cables. The included cable was just a bit too short for desktop usage and just a bit too long for portable use. I would recommend purchasing an additional short right-angle to right angle cable for portable usage and a long straight connector cable for desktop usage.

 
Portable Usage: I rate the B1’s portability ranging from acceptable to great, dependent on user preferences. I personally found to B1 to work well for my needs in the portable setting.
 
The B1 has larger dimensions and a heftier weight than many other competing portable headphone amplifier designs that commonly employ Class A/B designs rather than Class A. At the same time, the B1 is smaller and lighter than the only other pure Class A portable amplifier using discrete components that I am personally aware of: the now-discontinued Just Audio AHA-120 (80*126*26mm with a weight of 332 grams). I do personally feel that its size and weight is quite manageable as a portable device in real-life usage. My personal measurements for the B1 was 65mm*119mm*18mm.
 
 
There are no rubber bands or other materials included to use in creating a portable stack. Options for stacking will likely include purchasing third-party thick ‘audiophile’ rubber bands designed for stacking portable audio equipment. I personally prefer using third-party velcro-type solutions like the 3m dual lock over rubber bands for stacking equipment, but I was unable to try this option since my B1 is a review unit. The 3M dual lock gives a stronger-than-velcro attachment between devices with an adhesive backing to attach the dual lock strips onto the devices. I can see possibilities for placement of velcro-type strips on the window side of the device above and below the windows for a secure fit.
 
I would personally recommend stacking the device with the window against the back of your portable player/smartphone as the leather material makes for a very nice grip. At home usage, I like to leave the windows face up to see the cool lights and discrete circuit design. If the light becomes bothersome, simply flip the device over.
 
One other note for portable usage: this product can get a bit warm on high gain 40mA operation. On the lower setting, I had no concerns about the heat generated by this amplifier and feel comfortable leaving it in my pocket. I personally also felt comfortable with the heat generated during high current operation, but this can be a subjective thing.
 
I think that the B1 is well-suited for portable usage as long as you do not mind its slightly larger size and weight, and the generation of a bit of heat. Despite lacking a carrying case, the B1 is extremely transportable with a very durable and rugged feeling to its design.
 
IMPORTANT NOTE: The current adjustment switch should NOT be toggled while the amplifier is on and headphones are connected. This can damage your headphones!! During my extended usage of the B1, I never accidentally toggled of the current mode switch. However, this is quite an important thing to be aware of. I highly recommend testing whether you experience any switch toggling when placing and removing the B1 from your pocket without any headphones connected. I would recommend covering this switch with a small piece of black electrical tape if you have any concerns of accidentally flipping this switch. I do think that a different switch design for the current adjustment that makes it harder to change settings is an area for improvement.
 
***Update 6/5/15: I have experienced toggling on the power switch accidentally while the B1 was in my bag. Would recommend placing it in the bag with the switch side facing up to prevent this***
Sound Quality:

1. Dell XPS m1530 & Samsung Galaxy S5 smartphone > Combination of FLAC files, Tidal HiFi lossless, and Spotify Premium Ogg Vorbis
2. Please use this resource for the definitions of the audiophile terms I am using: http://www.head-fi.org/a/describing-sound-a-glossary

 
I found it was possible to experience a dramatic improvement in sound quality by adding the B1 for headphones that require additional amplification (especially if the previous set-up was underpowered). The relative differences between different amplifiers are much more subtle. The B1 still remained quite competitive among my personal collection of amplifiers.

​

 
The first thing noticeable about the B1’s sound is that it presents a very full bodied sound, but the sound signature remains extremely clear. The B1 can initially appear a bit tonally warm due to better sense of fullness and body presented, but there does not appear to be an overemphasis of warmth (especially apparent in a direct comparison against the warmer-sounding Woo Audio WA7 tube amplifier). The B1 does strongly present a sense of richness and fullness to notes. The instrumental “presence” is very realistic, providing a very lively and engaging sound that seems to be dancing in the room with you.
 
The B1 never sounds extremely sharp or bright, but still maintains an highly accurate and detailed sound. Do note that I do not possess any pair of headphones that I find to be overly bright in their presentation. I do imagine that if paired with an extremely bright sounding headphone, the B1 will retain that tonal presentation. There did seem to be a bit of an additional sense of clarity and air for headphones that originally possessed that sonic attribute. However, the B1 would not add airiness or crispiness to headphones that did not originally have that kind of presentation.
 
I found that there appeared to a bit of softening to the transition of the notes due to the nice smoothness at the end of the notes rather than a more abrupt edgier shift between notes. The spacing between notes remained adequate, but very dependent on the headphones used to test. However, the B1 was still very capable at producing clean hard-hitting attack transients with very realistic weight and power behind each note. The bass attack was extremely realistic and punchy. The rich full body and presence underlying the tones was still kept in check with a great sense of control over the bass speed. Attack transients very well represented and extremely tight. A barely audible lengthening of the decay could be detected in comparison. This does provide a bit of a nice smoothness to the sound signature, allowing the music flows very cohesively without ever sounding too abrupt. The B1 helped tighten up the bass notes on headphones with a boomier or flabbier bass response.
 
The B1 adds a really engaging vibrant element about the bass. There may be a hint of extra mid-bass impact that really brings out a more visceral presence to the bass notes. The B1 also presents a subtly tighter bass and subtle sharpening of treble detail with switching between current modes for certain headphones (most noticeably the orthodynamic headphones in my collection). I felt like there was a noticeable improvement on the HE-560 and HE-1000 using the higher current mode. For the PM-3 and LCD-X, the differences between modes was harder to detect.
 
The texture and micro-detail of the notes within the midrange was smoothly rendered. The sonic improvements found within the mid-range varied depending on the headphones tested. Do note that changes that I will discuss in this paragraph are quite subtle adjustments. Headphones with a more organic-focused presentation such as the LCD-X became even smoother and more liquid with very fluid changes in tone. While the HE-560 already has a stellar midrange presentation with a high resolution for revealing micro-details, I did feel that the HE-560 greatly benefited from the extra sense of fullness to the body of its notes as its clinical nature sometimes gave the feeling of a bit of thinness throughout the frequency response. The AKG K553 and K7xx maintained a very good balance between an analytical presentation and an organic focus with the pairing of the B1. The PM-3 experienced a notable improvement in its overall sound quality with its smooth articulate midrange further refined. While there were variable amounts of improvements for the mid-range depending on the headphones, I found the B1 to continue to emphasis the sonic characteristics of the midrange each headphone. It did not greatly alter the overall presentation or tuning of different headphones, but presented additional polish to their respective differing sonic characteristics. I did find that the B1 to be a quite transparent and clean sounding amplifier.
 
I would not characterize the presentation as more intimate or more spacious, but the B1 accurately reflects the presence range and soundstage of the headphones and source tracks being used. It do get a very realistic sense of the instruments being in the room around me. Imaging qualities of the headphones are maintained or even improved. The sound stage significantly improved on the PM-3 as it was easy to hear the difference with the PM-3 slightly intimate presentation. For the other headphones, there was variable subtle improvements to the sound stage, but could be very difficult to detect.
 
Overall, the B1 provides a highly resolving, rich, articulate sound that stays true to the headphones’ sound signature.


 
Headphone Pairings:
*******Important Notes*******
Tested with my source volume maxed, only controlling volume via the B1's pot
Tested each headphone listed on the B1 against the same headphone with:

1. no amplification
2. the Oppo HA-2 lineout to amplifier only
3. the Schiit Lyr 2 desktop tube hybrid amplifier (best amplifier in my collection imo)

*********************************
I could not fit my thoughts on how my entire collection of headphone pairs with the Aune B1 in this review.
Link HERE for further detailed impressions on specific headphone pairings with the Aune B1.
 
Overall thoughts on headphone pairings: I do want to note that some of my comparative findings were quite extremely subtle changes that required very extensive direct comparisons and even then, I am still a bit hesitant about certain aspects of my findings. Please note that you may have different experiences due to differences in our headphone and amplifier background.
 
The B1 had minimal coloration to each headphones unique sound signature. Improves different aspects of sound quality on each headphone while maintaining the headphones’ original tuning and frequency response. Suitable pairing for headphones that you are already satisfied with its sound signature. Not suitable as a method for trying to ‘tune’ or adjust to the headphones’ sound signature, and will not ‘fix’ frequency response flaws of your headphones. Can cause a dramatic improvement for headphones that benefit or require additional power. More subtle degree of improvements for headphones that can be driven without an amplifier.
 
 
Direct Amplifier Comparisons:
*******Important Notes*******

1. Compared the performance of each amplifier against the B1 using the AKG K7xx, PM-3, and HE-1000
2. I believe the K7xx and PM-3 are very highly resolving neutral-orientated headphones that are strong representatives of high quality mid-tier open and closed categories. I also used the HE-1000 as it is the most resolving headphones in my collection with the greatest scaling potential.
3. Please remember these are my own personal subjective impressions. YMMV!!!

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Against the Cozoy Astrapi portable dac/amplifier:
MSRP: $139.99 (can be found for $129.99) - Portable usb dac with solid state amplifier (unspecified, but most likely Class A/B)
**Cannot compare against the amplifier portion only as it has no line-in**
 
Design: The Astrapi is much smaller, more compact in all dimensions, and much lighter. Very portable dac/amplifier combination. No internal battery and is powered by the connected smartphone.
Sound: Astrapi has bit warmer overall sound signature with a smoothed-over treble. While the Astrapi has very competitive sound quality at its price point, it is not as resolving and technically proficient as the B1. The most noticeable differences is that the B1 has a larger soundstage with better sense of imaging, a cleaner more neutral-oriented sound signature, more revealing of micro-details and subtle textural variations, more realistic sense of presence to the body of notes, and a better defined quicker transient response.
Overall thoughts: Astrapi has competitive performance for its price point and excels as a portable all-in-one amp/dac solution for those requiring the most minimalist slim design. Consider the Astrapi if portability, size, weight, and small form factor as your primary concerns. More suitable for those who enjoy a subtle hint of warmth in their sound signature.
Personal Pick: Application specific. I use the Cozoy Astrapi when extremely limited pocket space or when I do not want to carry a lot of extra stuff with me. The Astrapi is extremely portable and very convenient. The Astrapi does not require recharging as it draws power through the usb from the source device. I use the B1 during travel (vacations, airplane flights), commutes (subway, driving), or on-the-go when I don’t care about pocket space. Also, I would use the B1 if concerned about smartphone battery life as the B1 does not drain any power from your smartphone.
 
Against the Oppo HA-2 portable dac/amplifier:
MSRP: $299 - Portable solid state Class A/B amplifier with dac (ES9018-K2M dac chip)
**Compared against the HA-2’s amplifier section only via the line-in**
 
Design: The HA-2 is thinner, taller, and lighter with the dimension of 68*157*12 mm and weighing 175 grams. The HA-2 also is leather-bound with a metal chassis.
Sound: The sound quality between these two amplifiers was extremely difficult for me to personally detect even after very extensive direct comparisons. Only when using the HE-1000 could I really even begin to really pick what exact differences consistently. The only comments I am comfortable making is that there appears to be a bit extra sense of fullness and body on the B1. There may also be a subtle underlying richness on the B1 that is harder to detect on the HA-2. The B1 seems to have a harder hitting attack and a bit more texture to its bass notes. Perhaps a bit more cleanly defined bass and a subtle mid-bass emphasis compared to the HA-2. The B1 has a bit more breathiness. I do think the comparative differences is also dependant on the headphones that are being tested, so don’t take this comparison too seriously as ymmv! I do personally think that the differences between well-designed solid-state amplifiers can sometimes be extremely hard to pick out in a blind test. I view significant differences as sonic aspects that can be easily picked up within one or two quick direct comparisons. I had to do much more testing to find differences in performance between these two amplifiers. Overall, it appears that both these amplifiers are quite well-designed and provide extremely solid sound quality.
Overall thoughts: The HA-2 was my personal pick as an external amplifier/dac solution after extensive research, and I do personally find it well suited for my needs with very competitive performance at its price point. I consider it to be a ‘premium’ portable amp/dac combo while staying within the affordable price range. I used the HA-2’s amplifier via line-out to extensively compare against the B1.
Personal Pick: Tied. I think the different design characteristics of these two devices will primarily determine which one is more suitable for your intended application. The sound quality between the two devices are both extremely competitive and it was extremely difficult for me to consistently isolate the exact differences in sonic characteristics.
 

 
Against the Resonessence Labs Herus usb dac/amplifier:
MSRP: $350 - USB dac with solid state amplifier (ES9010-2M dac chip)
**Cannot compare against only the amplifier section as no line-out**
 
Design: The Herus is thicker but much shorter in width and length. It also weighs less. The Herus’ boxy design makes it less unsuitable for portable usage (in my personal opinion) as it does not stack well. No internal battery, so will be powered by your smartphone or computer.
Sound: The Herus has an overall brighter sound signature and sounds ‘crispier.’ Extremely clinical-oriented presentation in my personal opinion. May sound sharp depending on your treble preferences.
Overall thoughts: The Herus is more suited for desktop usage, but extremely transportable. Can possibly use portably, but not the best choice for that application in my personal option. Consider the Herus is you require a stand-alone usb dac and amplifier combination and enjoy a brighter presentation.
Personal Pick: Aune B1 (especially B1 paired with a dac of my choosing)
 
Against the Schiit Lyr 2 desktop tube hybrid amplifier:
MSRP: $449 - Dynamically Adaptive Class A/AB tube hybrid amplifier
 
Design: Desktop solution, not portable at all. Chassis becomes extremely hot!
Sound: Slightly warmer and fuller sound with subtle tube coloration. Noticeably second harmonic distortion for a “tubey” sound. I personally find the Lyr 2 to have a very well-refined balance of an engaging euphonic richness while maintaining great detail resolution and technical performance. Extremely good sound quality attributes including spacious soundstage, precise imaging, tight transient response, vivid sense of energy, sturdy control throughout the dynamic range, and highly resolving micro-detail retrieval. I do think that the Lyr 2 is a superior technical performer though the B1 remains relatively competitive and close in overall performance.
Overall thoughts: Not a direct competitor product. This is my personal favorite amplifier out of my collection and I believe it is a strong performer at its price point. The relative difference in performance was much smaller and more subtle than I expected from my direct comparisons. I was really surprised by the relative closeness in performance of the B1 to the Lyr 2 despite the Lyr being one of the most competitive options in the sub-$1000 category. While I still think that the Lyr 2 offers the best overall sound for my tastes out of my amplifier collection, the B1 is quite technically capable amplifier and stays extremely competitive. The B1 may even be preferable for audiophiles do not enjoy the slight euphonic coloration provided by tube amplifiers and are looking for minimal coloration in their amplifier.
Personal Pick: Schiit Lyr 2 in desktop applications
 
Against the Woo WA7+WA7tp desktop tube amplifier:
MSRP: $1,398 - Pure Class A transformer-coupled tube amplifier
 
Design: Desktop solution, not portable at all. Can get a bit hot.
Sound: WA7 has a much warmer sound. Very noticeable coloration in direct comparison. Pleasant euphonic distortion, “richer sound.” Soundstage and imaging not quite as large or precise with a more intimate presentation and subtle emphasis in the presence range. A subtle rounding and smoothing of notes with a blurring effect in the transient response. Spacing between notes not as tight. A bit longer decay times. Focuses more on presenting a ‘liquid’ smoothness to the textural shifts rather than highlighting the micro-details.
Overall thoughts: Not a direct competitor product. The WA7 may be suitable for people looking for an all-in-one desktop pure tube amplifier solution with a dac. I feel that the WA7 is better for people who enjoy a very warm, smoothed-over, pleasantly colored sound signature, and strongly appreciate the aesthetic design of their products.
Personal Pick: Aune B1 in both portable and desktop applications (especially with a dac of my choosing over the WA7’s built-in dac)
 
***Update 6/5/15: I have done direct sighted comparisons of the B1 against a few other desktop amplifiers using the HE-1000. Not a fair comparison I know, but I have found that I could hear a subtle differences in sound quality against the Hifiman EF100. It was more difficult to hear the difference against the Audeze Deckard. There was a significant upgrade in sound quality in a sighted test (specifically with the Auralic Taurus MKII, Beyerdynamic A2, and McIntosh MHA1000). Differences were most pronounced in the MHA1000 which I found to be the best sounding amplifier out of all the ones I tried. Extremely life-like and gorgeous sound! The direct comparision with the MHA1000 is the first time I noticed extremely significant scaling with external components. A direct comparison against Chord Hugo did not yield that much of a sonic improvement to my ears. The sonic upgrade was significantly more easily noticeable on the MHA1000 over the Chord Hugo in my opinion. The Chord Hugo alone definitely does not drive the HE-1000 to its full potential. Using these amplifiers and dacs, I could definitely see how the HE-1000 scales up greatly with different components and would recommend investing in a more high-end amplifier for the HE-1000 to maximize its potential.***
 
***possible additional amplifier comparisons (including the Liquid Carbon and the Oppo HA-1)***
 
Value Judgement: Excellent
 
I would personally always recommend an external portable amplifier or external portable dac/amplifier combination over an audiophile-targeted dedicated audio player. You can normally get more competitive amplifier and dac components at the similar price point and you have more versatility as you are not tied down to the player’s UI and can use your smartphone/laptop as a source as well.
 
Considering that many smartphones and computers have quite capable dac chips nowadays, I do believe it is quite reasonable to skip an external dac (especially for a portable set-up). The nice thing about a standalone amplifier is you can choose your own dac pairing, ranging from inexpensive budget dacs such as offerings from Hifimediy or Stoner Acoustics or more expensive options like the Cypher Labs Algorhythm Solo.
Do note that if you are looking for a compact external amplifier/dac, the B1 will not suit your application.
There are also usb stick-sized dacs with built-in amplifiers that can feature a much more compact design, but will generally not have as nice quality or powerful amplifier. Majority of these options also requires special OTG adapter for Android devices or a lightning camera connection kit for iPhones to utilize the dac. Some examples include the Audioengine D1/D3, Audioquest Dragonflyv1.2, CEntrance Dacport, HRT Music Streamer line-up, LH Geek Out, Meridian Explorer 2/Director, Resonessence Labs Herus/Herus+, and Schiit Fulla.
 
For people looking for an high-performing dedicated portable amplifier, the B1 is a very appealing high performing option with an affordable price point. From my research, I do think the B1’s price point is quite competitive for its unique topology and design even among the current market offerings.
 
Considerations for Prospective Buyers:
 
My Overall Ratings (as I believe the side-ratings on head-fi are averages):
Do note that I hardly ever give out full score ratings even on extremely good products. Reserve that rating for products that I feel far exceed and redefine my previous notions of what is capable
 
Audio Quality: 9/10
Design: 8/10
Quality: 8/10
Value: 8/10
Overall Score: 4/5
 
The greatest sonic pro of the B1 in my mind is its full, rich, detailed sound with minimal coloration. The B1 has extremely competitive high-quality sonic performance even above its price point with the versatility to work with a wide range of headphones from sensitive low impedance IEMs to high-impedance dynamics and hard-to-drive orthodynamics. It also features a stylish design and a very competitive price point.
 
The biggest con in my mind with the B1 is the lack of accessories (especially the lack of a short right-angle connector often provided by competitors even at lower price points). I do strongly feel that those accessories should be included at this price point. There is also room for improvement to its design (marking the volume pot, indicator light improvements, possible concerns of accidentally switching the current switch). Other important properties of the B1 that warrant individual consideration are listed below.
 
Important considerations for potential purchasers:

1. A dedicated amplifier only. May not suitable for those looking for an all-in-one dac/amplifier combination. Does give the flexibility of pairing with personally preferred portable or desktop dacs (especially helpful if you have different dac preferences for different headphones). This can be a pro or con depending on your requirements.
2. Class A design will generate heat and requires a larger footprint/weight compared to some of the other portable amplifiers on the market (especially compared to traditional Class A/B designs). My personal experience with the B1 was not really affected by those factors, but how those qualities of the B1 affect you will be a personal subjective call.
3. Battery life ranges from 5-10 hours. May not suitable for those looking for an portable amplifier that can last multiple days without charging (though do note whether its battery life is sufficient for your needs will be dependent on your usage habits).
4. Should work with the majority of headphones on the market as I was able to test it with high impedance headphones (DT880 600 ohms) and some orthodynamics. Do note that all Audeze and Mr. Speaker headphones are easier to drive than the HE-560 from a technical specification standpoint. However, the older Hifiman headphones such as the HE-4, HE-400, HE-500, HE-5, and especially the HE-6 are harder to drive than the HE-560 from the calculated power requirements and I was not able to test the B1 with any of those headphones. Pairing the B1 with the old Hifiman headphones will require additional research (ask for impressions from owners).
5. Does not drastically ‘tune’ your headphones’ sound signature by adding excessive coloration. Not suitable for those trying to find an amplifier to significantly alter their headphone’s sound signature.
6. Does NOT have a bass boost feature. Not suitable for those who are looking for that specific feature or are looking for a heavy bass quantity emphasis. Do note that the B1 does offer sonic improvements to the bass quality.

 
Conclusion:
 
The B1 provides ample power for all the headphones I tested with a clean black background. It adds minimal coloration to the sound signature, so the source and headphones can be heard accurately. Providing sonic improvements to the weight, fullness, and richness of notes throughout the frequency response, the B1 is extremely detailed, highly resolving, and true to source.
 
A quite strong application of the B1 that may be overlooked is using the B1 as a stand-alone ‘transportable’ amplifier. I personally found this to be the B1’s best strength. It’s small size in comparison to other ‘transportable amplifiers’ allows for a very easy carry from one location to another. Whether going to work/school, travelling between hotels, or moving between rooms in the house, I found the B1 to really shine in that setting. Plugged into a laptop, there is no need to worry about checking the battery indicator lights for battery life.
 
I personally found packing the B1 while travelling on vacations or business trips added a great deal of convenience as one piece of nice audio setup. Not only can it be used while on-the-move (flying in airplanes, sitting in subways, walking on the street), but it can be used while working at Starbucks or chilling in the park. I do strongly feel the B1’s sound is extremely competitive even beyond other portable amplifiers with performance that allows it to be used as a viable alternative to traditional desktop amplifiers. I have personally been utilizing the B1 the most often as a "transportable desktop amplifier."
 
While it is possible to use the B1 purely on-the-move in your pocket as well, the B1’s larger size and weight compared to the competition makes it bit less suitable for that specific application for the general consumer audience (in my personal opinion). I would personally recommend the B1 more for the really serious audiophile who emphasize sound quality over convenience and the portability of their audio stack. Other audiophiles I think this product would greatly appeal to are audiophiles with multiple different listening locations who would benefit from an easily relocatable  “transportable” amplifier solution. Finally, audiophiles requiring portability with multiple dacs and various headphones may appreciate the standalone approach to an external amplifier providing clean power for dac and headphone synergies to truly shine.
 
While I do personally think that Class A topology does not inherently mean a superior sounding amplifier, I found the B1 to be an good example of well-designed, well-implemented Class A amplifier with solid sonic performance. I am not aware of any other currently in production fully discrete Class A portable amplifier, so this device seems quite unique. While this device may not be for everyone, I would highly recommend audiophiles interested in high performance affordable portable amplifier to audition the B1 as it has very compelling sonic performance for its price point.
 
***UPDATE 6/5/15: Please check out this post HERE if interested in signing up for a home audition of my review unit. My demo tour will last as long as there are interested people wanting to try this item. Please post on that thread or PM me directly***
***UPDATE 6/10/15: My US tour of the B1 has officially started & has been shipped out***
 

 
Product link: http://en.auneaudio.com/html/en_products1/Portable_series/190_11.html

One of my favorite parts of this hobby that I've grown to love over the past few years is trying new things and just experiencing how different components (or combination of components) have their own unique way of expressing what is essentially the same music. So when Aune Audio began looking for reviewers of their B1 amplifier, I jumped on that train real fast. I’d like to give a big thank you to Aune Audio for providing me a unit to review and, of course, my review is solely my own opinions and I am in no way affiliated with Aune Audio.
 
            The Aune Audio B1 came well packaged in a DHL bag, a brown box, and finally its actual box. The box is sturdy and simple. Inside, you find the amp, manual, a business card, a USB cord for charging, and a short 3.5mm to 3.5mm cable. The overall presentation is simple but very nice, and Aune provides everything you may need to get the B1 up and running. The only thing that I would have liked to see is some sort of storage case, or even just a nice little bag for it.
 
 
            The Aune B1 is built like a tank, and it’s a damn good looking amp. Its chassis is built from brushed aluminum with only its volume knob being made of plastic. The B1 feels solid and has a nice heft to it. The build quality leave little to be desired and a whole lot to admire. My unit did come with two tiny tiny scratches, on at the bottom of the amp, and one on the volume knob that made me a little sad. Honestly though, build is awesome!
 
            It’s clear that the engineers over at Aune Audio paid a lot of attention to detail when designing the B1. The “highlight” of the B1’s design is obvious its two windows that show the components inside the amplifier. When I first saw a picture of the B1, I thought it was some sort of portable tube amp. I mean c’mon… looking at the tubes is half the fun! Now obviously the B1 isn’t a tube amp, but I still think displaying its internal components was a pretty cool little feature and is definitely a bonus in terms of aesthetics. The LED lights just make things even more awesome to look at.
 
            The buttons around the B1 are also well designed. Most of the functions of the B1 are controlled by sliding switches, where you slide it to turn a feature on or off. To prevent the switches from being easily changed, Aune had the chassis on the sides slightly indented. I don’t think that’ll solve the problem completely, but I personally had absolutely no problems with the amp accidentally shutting off or accidentally blowing my brains out by switching to high gain, so hey… what do I know, maybe it’s doing its job just fine.
 
            The back side of the B1 is well designed with two strips of material that keep the amp from sliding too much on a flat surface and prevent the amp from scratching. Now I won’t pretend to know what material it is, but I would guess that its pleather (I don’t think its real leather?). All I know is it looks very nice and gets its job done.
 
Size wise, I think the B1 is very reasonable. It’s a little taller than my iBasso DX90 with about the same width. The two as a pair looks very nice!
 
My only gripe about the B1’s design is that if you decide to make a portable stack by rubberbanding a DAP to it, it’ll block off the gorgeous display of its components unless you use the other side. But then that defeats the purpose of the pleathery material protecting the amp and you risk scratching the amp. Oh well… it seems inevitable.
 
Again though – Built like a tank and damn good looking.
 
 
            The B1 is quite a special little device. Not only is it a class A portable amp, which is not all that common, it also has an interesting current switch that gives it a bit more flexibility in driving more demanding headphones. In addition to that, the B1 also includes an on/off switch, micro USB charging port, battery indicator, and of course a volume knob, input jack, and headphone out jack.
 
Being a class A amp, the B1 does get quite warm after using it for some time. It remains very safe to touch though and never gets overly hot by any means – definitely still very safe to keep in your pocket or to use portably.
 
What’s kinda bizzare is the current switch. In the B1 manual, Aune quotes in RED, “Never flip [the current switch] under B1 is working.” Ignoring the slightly broken English, it doesn’t sound like Aune is messing around. I wonder what would happen if I just … …
 
            The B1 is advertised to be able to run for 10 hours with low current and 5 hours with high current. I did run the battery dry on low current and got approximately 9 or 10 hours out of it. I didn’t keep a strict count, but the battery life is certainly around what it’s advertising to be. 10 hours isn’t bad, but it is trumped by other portable amps that can last 20, 40, or more hours (The most I’ve heard of is like 80 hours or something. That’s pretty insane.). However, remembering that most high quality audiophile DAPs currently on the market can barely last 10 hours, it’s not a problem at all. You’ll just have to remember to bring two chargers along when going on a long trip! Plus, remember that it’s a class A amp and, thus, fairly inefficient, I guess 10 hours is actually pretty good.
           
            I didn’t bother running the B1 on high current to see how long it lasts, as I don’t see that as necessary. If I’m running it with high current, I’ll probably be using a fairly demanding headphone, which means it’s not portable and I’ll probably be near some sort of power source where I can freely charge up my B1.
 
                   Listening was done with my iBasso DX90 as the source running line out into the B1 and then into my Earwerkz Supra 2, HIFIMAN HE560, and HIFIMAN HE1000 (just for fun and cuz I have it with me as a beta unit… why not). Basically all genres are covered and all audio files ranging from 256kbps and up (with the exception of DSD files) are used for my sound impressions.
 
 
Noise Floor
The B1 is quiet. With my Earwerkz Supra 2, one of the most sensitive I know, it does have a tiny bit of hiss, but a VERY manageable and hardly noticeable amount. It is one of the quietest amps I’ve had the pleasure of listening to and I wouldn’t worry about it hissing at all honestly – very nice and very dark background. The DX90’s amp section still trumps it in terms of noise floor, but it’s hardly a difference at this point.
 
Channel Imbalance
The B1 does have a bit of channel imbalance issue that could be problematic, as the B1 also happens to be pretty loud. Running DX90 > Aune B1 > Earwerkz Supra 2, I had to set the line out volume of the DX90 to 200/255, which is the lowest I’ve ever had to set it, in order overcome the regions on the volume knob where the B1 has its channel imbalance. So what does that mean? Well first off, those using the most sensitive IEMs may need to do a bit more research or to give the B1 a listen first to make sure that the B1 is a good match with the sensitive IEM. And second off, those that do not have digital control over their line out signal may also need to do more research. It’s really unfortunate to see that this may be the dealbreaking point for those using the most sensitive of IEMs because of the sound that the B1 produces (hint: it’s awesome).
 
Sound (For Real Now)
            As a whole, I think the B1 is one of the most neutral portable amps that I’ve ever heard, and is certainly the flattest sounding in the sub-300 dollar range that I know of. And that’s a good thing. I really like this neutrality that the B1 has.
 
B1 compared to Amp section of DX90 (Using Earwerkz Supra 2)
            I love my DX90 and I consider it to be one of the best (if not the best) DAP currently available under 500 dollars. I do have a few gripes about it though, as I feel that it is just a bit warmer and smoother sounding than I would prefer it to be. The B1 addresses that issue for me quite beautifully. When connected to the DX90 via its line out, the improvement over using just the DX90 alone is significant.
 
            The most obvious change and improvement come in the bass department. The B1 removes the midbass bump that I find the DX90 to have, and bring on better bass extension. What you get is a much cleaner, tighter, and faster bass that retains a very fun sound all while making the sound straight out of the DX90 seem muddy and bloated in comparison.
 
            The midrange of the current firmware I’m using on the DX90 (FW 2.2.0) was a little forward and can be just a bit thin and unnatural sounding for me. The B1 also helps the DX90 out here. It pulls the forwardness back just a tiny bit while giving the midrange more fullness by presenting a flatter upper midrange that fixes the DX90’s slightly unnatural tone.
 
           The treble from the B1 extends better than that of the amp from the DX90, giving the sound slightly more air. The B1 also adds a nice crispness to the sound, but never making the sound harsh or bright.
 
            The other major improvement that comes with the B1 is the soundstage and separation. You get a significantly larger soundstage, particularly in width, which really opens the sound up. Separation is also a very big step up compared to listening with just the DX90. The sound from the DX90 alone is claustrophobic and congested in comparison to the very nice and open sound when you add the B1 into the picture.
 
            After spending some time with the DX90 connected to the Aune B1, it’s honestly very hard to go back to listening with just the DX90 as the B1 just tightens and cleans up the sound so fantastically well. This is not to discredit the DX90 of course. It’s a 400 dollar all-in-one box solution with everything stuffed into a very small box. On the other hand, the B1 is 200 dollar standalone amp that’s bigger than the DX90. Hell it better be better than the amp section of the DX90. What is awesome, however, is just how much better it is. The B1 really is a fantastic sounding amp and if you’re willing to sacrifice some portability, it is very well worth the additional 200 dollars and extra bulkiness. This thing simply sounds fantastic.
 
DX90 > B1 > HE560/HE1000
            This portable combo drives the HIFIMAN headphones quite admirably if I must say, and in the event that I’m traveling and staying at a hotel or something where I can use my full size headphones but obviously couldn’t bring along my full size amplifier, I would be happy to live with this combo for the time being.
 
            Some things that it tends to lack while driving these headphones in comparison to my Asus Essence III:
 
-The bass extension and punch is good, but it does lack the last bit of bass extension that gives the rumble that planar magnetics are so famous for
 
-Overall soundstage is a bit smaller but holds its own. The B1 tends to lack a bit of depth, and that really comes out when paired with the HE1000. The HE1000 is a fantastically layered headphone with great out-of-head imaging, and it clearly doesn’t perform its best in terms of soundstage and layering when paired with this combo.
 
-Not surprisingly, the detail retrieval of this portable set up is not on par with the much more expensive Essence III, but for the price, it does a very respectable job.
 
            So I also tried listening to the HIFIMAN headphones with different current settings, and honestly I don’t hear all that much a difference. The HE560 and HE1000 are not notoriously hard to drive. If anything, they’re some of the easiest orthodynamics on the market. I would guess that perhaps the current switch would make more significant of a difference on headphones that are more difficult to drive. I would swear that the HE1000’s treble is just a teeny tiny bit sharper when the current is set to high, but I would really not bet my money on it. For me, the difference between the two settings was pretty much nonexistent.
 
Summary on Sound
            What you get from the Aune B1 is an impressively detailed sound that is very well balanced and gives a great sense of space. I wouldn’t be inclined to call this amp warm nor cold. To me, it’s simply pleasantly balanced and uncolored. Despite that, the B1 is in no way boring to me as it has a very tight, crisp, and detailed sound that just begs you to take notice of it. I’m very happy with what the B1 offers and I think it is of fantastic value at its MSRP of 200 dollars.
 
            Aune Audio was a company that I was aware of, but never paid all that much attention to. I know they made some well-regarded desktop friendly components, and I thought their company logo was pretty slick looking, but that’s about it. My experience with their B1 amplifier really put them on my radar. I obviously hold the B1 in very high regard, and I think it’s a gorgeous piece of gear – inside and out. I would like to thank Aune again for the opportunity to demo this beautiful portable amplifier, and I’ve very excited to see what products they have planned for the future!
            Do I recommend this product? Absolutely yes. The only thing keeping me from giving the B1 a full 5/5 is its channel imbalance issue. If Aune is able to resolve that issue somehow, I think this amp would be an easy recommendation to just about anyone looking for a portable amplifier at this price. But for now, those using a DAC with a powerful line out signal combined with a sensitive IEM may want to think twice about purchasing this amp. For anyone else, go crazy! 

 

 

 

 

Introduction:

 

There haven’t, erhm, been too many Class A portable amplifiers on the market, so introducing this as part of a group is quite difficult. The Lear FSM-2 V2 may be one of the only other ones I’ve heard of, and even then only fleetingly, and at more than double the price point of the B1. In terms of power, though, there has been a few budget amps that pack a punch, including but not limited to the Fiio E12 we all love at its price point.

 

So, the point? That Aune’s B1 is quite interesting before we even start, by doing something almost nobody else had the guts to do – a fully portable class A amp, for all those that don’t want to be glued to a wall outlet (anybody? Any takers? Well, me for sure). Yeah, you could go for the E12, but what if you’re past budget-fi, and want to do justice for your more power-hungry headphones, and your X5/dx90/A&K player to boot? I was recently put in that situation, where I was blessed enough to be able to get both the AKG K7XX and the Shozy Alien. So then all I needed was an amp.

 

How hard could it be already?

 

Hard enough. I went through 5 or so amplifiers, the E12 the only one powerful enough in my opinion to drive the K7XX to a fuller sound (none had problems with volumes, but then again, volume isn’t everything, right? Quality is the beast we’re discussing here), and couldn’t help but wonder if it was limiting the wonderful sound my other two pieces of equipment were capable of producing. So I jumped at the chance to get a B1, hoping that class A was what I was looking for, while also hoping power wasn’t the only good thing the B1 was good at.

 

It’s good alright. Very, very good. But more of that in the review. Let’s begin!

 

Packaging:

 

I’m not a fan of this section in general, but while I’m at it, I am a fan of the B1’s packaging. Nice an’ simple, just the way I like it. Comes with a 3.5mm to 3.5mm cable, as well as an usb charging cable – standard, not a feared proprietary cable like Cowon’s.

 



 
Build Quality & Design:

 

Tank certified, in my opinion. Much better built than the Schiit Magni 2 Uber I’ve owned, though that wasn't too shabby either. Made almost fully out of metal, and, although I have no idea how I know this, it feels like the metal is thick as well. No hollow-ish sound I’ve had when the components didn’t exactly fit the case they were assigned to; the B1’s case feels like it was made in Germany, ja? I would be afraid of dropping it though due to the fancy see-through glass, although through my rigorous tapping tests I’ve decided it’s pretty sturdy as well. Don’t drop this though – well, make that don’t drop any of your audio equipment, unless it’s created by Apple.

 

Speaking of the see-through screen, it gives this amp a look of authority. Man, I’m usually scared of anything see-through – it reminds me of the components inside and how they could break. But with the B1, I don’t have this problem. It’s really weird, I was expecting to treat this like a vase, but instead I’m treating it like a Swedish Volvo, carrying its own weight and build quality plenty. I’ve never seen a sturdier built amp around, even with the partial see-through screen, and that’s saying something. The symmetrical led lights the amp gives when powered on is classy to the max. My initial impression when I took this out of the box was that I could probably convince my roommates it had a built-in wine flask.

 

The leather backing on the other side only confirmed my wine-flask theory. Soft and comfortable, this is another point for the B1’s classiness.

 

The volume knob is the only thing that people may take up for debate. It is made out of hard plastic, not metal. Now before people start arguing that the E12 has a metal knob and thus better, I just want everyone to know that the plastic Aune used here is just fine in this case. The knob moves smoothly, and it doesn’t appear to shake or wobble no matter how hard I try. So will it stay working for 3+ years? I couldn’t tell you, but it seems well-built enough to stand the test of time, in my opinion. Although a diamond knob would have completed the classy setup, there’s only so much you can expect for $200, you know?

 

My, they really had a wonderful designer when they made the B1; it looks like it just came out of fine dining, with no way to argue otherwise if I had even wanted to. It simply just looks really, really good all around. Sturdy and elegant, more well-designed than any other piece of equipment I ever handled. Well done, Aune, seriously. I just wish the volume knob could have been outta diamond/platinum, ‘cause that’s really the only thing that anyone could ever nitpick about.

 

Basically, Aune did well in this department. Not only is it built like a tank, they managed to add the see-through-glass/led-lights/leatherback for a classy, well designed look.

 



 
Buttons/Switches:

 

I’ve already discussed the knob, so moving on one side there’s the power switch, current switch, and gain switch. On the other side there’s the power indicator 


button. All of the first 3 seems well done, and doesn’t look like they would be switched on/off accidentally, which is what I was hoping for, especially given the fact that so many got it wrong in that regard. At the same time, though, they’re also not hard to use if you try, albeit a bit on the safer/heftier side in that regard. I’ve been furious for a while that the E12’s side buttons (gain, crossfeed, etc.) are meant to be used with a toothpick, and even when 3 inches from my nose is incredibly hard to use. Fun fact: I actually thought when I got the E12 that the buttons fell off and I was seeing the mechanics behind it. Like, yeah. So all I’m saying is I’m happy the B1’s buttons are very useable.

 

The power indicator button works fine, and I’m glad Aune incorporated it, as it’s a brilliant way to check and see how much battery is left.

 

As for the switches themselves, the power switch is self-explanatory, so I’ll continue with the other two. The gain switch provides a 10db or so volume boost, which works well for the K7XX, but isn’t a shocking jump, when using full-sized headphones. With IEM’s, such as the SA7, it’s a bit of a jump if you hit it by accident, but I don’t see that happening anytime soon. The current switch goes between 20MA and 40MA, although even with power-hungry headphones like the K7XX I could barely hear a difference; I think the 40MA current provides slightly more authority to the sound, although the difference is so small I’d be more than happy if I had to live with only the 20MA. The reason why I’m saying this is because the battery gets halved (more on that later) when under the higher current, and many of you are probably wondering if it does well on the “low” current as well, for more portable uses. But fear not; both sound amazing, and the 20MA doesn’t sound thin in the slightest. If I understood correctly though, both of them are class A currents, so there’s no real “low current” here, only high and higher.

 

It is important to note that Aune strictly advises against switching the current when powered on, so many might nitpick with that. But to me, if it’s not prone to accidents, and you have the foresight to keep Aune’s warning in mind, there’s nothing to talk about.

 

Battery:

 

Let’s take a step back and consider what current this lion is giving us. Fully class A. Now taking that, let’s consider its battery life; 10 hours for the 20MA current and 5 for the 40MA. At first glance, this would make people recoil. But after you consider the wattage we’re getting here, it suddenly turns into a gem. 13 hours on the Oppo HA-2? No problem, we’ll get you a Schiit Asgard current in a portable package straight away.

 

Seriously, though, if you know what we’re dealing with here, 10 hours should raise eyebrows. And especially since you probably won’t even need to use the high-current when you go outside (unless you’re using 300 ohm IEM’s,) you'll only have to worry about the ten hour battery, not the 5 hour one. I’m usually not a fan of current switches, as they’re usually an indicator that the low current is not enough, but with this I’m keeping it in low current and taking the 10 hours with me. Low current still powers my headphones like a boss. For a Class A, truly a remarkable feat.

 

*Now, I wish Aune told us whether the 10 hours is in low gain or in high gain, but I should be able to find out soon enough. Get back to you guys later on that.

 

Heat:

 

Since this is a Class A, can you fry eggs on it, as with many other infamous Class A amps? (I’m talking to you, Schiit Asgard 2!)

No, and a big relief at that. I’m happy to say that when using it all of today, the Aune B1 only gets slightly warm, never hot to the touch. A potential issue that many were worried about, Aune seems to have found a good lid for heat control on this one.

 

Size, Weight & Portability:

 

Size is small enough and at a good size, being exactly the same size (L x W) as the E12, while being just a tad thicker. Weight, though, is quite hefty. Obviously it’s liftable, but it may not be what you have in mind for your ultra-light setup. This is probably due to the components inside, so it’s all for good cause. Just thought I’d make a mention that this is not a featherweight amp by any means, and as a class A amp I wasn’t expecting it too. It should be great in backpacks and in inner coat pockets, but not in jacket/pants pockets, and definitely not while jogging. However, if you could get past the weight, portability is fine. Pictures:

 



Note: On the left is the Fiio E12, on the right is the Aune B1.
 

Amplification & Volume:

 

Volume is quite plenty, especially if you keep it in high gain. As far as amplification goes, my main IEM gains massively from high gain, while with the K7XX it’s not that much of a difference. If I had to point it out, high gain gives more of an edge to things, which in turn makes it feel more refined. With my KRK KNS-8400 and the Bang & Olufsen H6, though, low gain is also quite fine, although high gain still has a *slight* edge. So it seems that the SA7 at 50 ohms is the only one who doesn’t like low gain. It does beautifully on high gain, though, so there’s nothing to worry about here. As I have said, volume is not a concern with the B1, and the B1 works fantastically with everything I’ve thrown at it.

 

As I'll mention later on, the B1 is way ahead of the Fiio E12, especially when it comes to detail retrieval, clarity, and overall balance, all of which I will discuss in the sound section. As for the Schiit Magni 2 Uber (from memory; I haven't had the Magni in a good month or two), the Magni 2 has absolutely no viable edge to my ears when it comes to power because let's remember yet again that the B1 is a Class A amp. So besides for the fact that the B1 is powerful and portable, the B1 sounds yet better to my ears; Detail and musicality probably being its winning factors, but really the B1 -portable or not- is a step ahead of budget-tier amplifiers to me. The overall sound of the B1 is more than I could ever ask out of the Magni 2 Uber, possibly excluding the soundstage, which may or may not have been better on the Magni 2 (I can't really remember all that well now). In all other respects, though, I'd pick the B1 any day.

 

When comparing the B1 to the Heir Audio Rendition 1 amp ($330) - by memory, it seems that the Heir wins by a small margin when paired with IEM's, as that's the only thing it's geared to do. However, the B1 is not lagging far behind, and definitely takes the cake when it comes to over-the-head headphones, whether they be closed back like the KRK's or open-back like the K7XX. It's not really a fair comparison to begin with, as there's no reason to buy a Class A amp just for IEM's. The B1 has a lot more going for it than the Rendition 1, unless your entire collection is built entirely of IEM's, like @ClieOS .

 

Hiss:

 

The B1 has a very black background, and there's not much hiss at all unless I strain my ears to hear it on the highest volumes with my IEM, and even then I’m not sure if I’m imagining things. So no worries for your IEM’s here.

 

Sound:

 

Here’s the good part of the review, it’s as good sounding as it is classy. Much of the E12, and it should be, at its price point. Much more controlled in the lower end, detailed in the highs, and overall balanced. Here’s the breakdown:

 

Lows/Bass: Exactly where I want them, quantity and quality, like an iron arm. Doesn’t overpower my K7XX’s like some other amps do, and keeps everything quite even. I wouldn’t call this lacking in bass though, as when the song requires it to pack a punch, it does very well. Details on the low end are done very nicely, no uncontrolled bass lows on the K7XX’s anymore, which is more than I could ask for. The bass is very fast, which is the first time I’ve ever been able to pick that up on a piece of equipment, so I may be off or hearing something else there. I’d like to emphasize here that although I’m usually not quite impressed with the lows, the bass here really give definition and balance to the music.

 

Mids/Vocals: Vocals have no complaints from my end, especially when so many have failed me there. Guitars and other instruments are at its prime here, though. I’m savoring everything from the good ol’ Sultans of Swing up to my OCRemix albums that came out last year. Chrono Cross’s OST, when I played that game at 5 years old, doesn’t fail me here either, which makes me smile. Overall, mids are a beast, and instrumentals are glory with this one.

 

Highs/Drums: I was expecting some kind of roll-off here, as what can be perfect? But, contrary to my expectations, highs are as crisp and detailed as they come, without being bright to my opinion. Not emphasized, but with a strong presence, as they should be. I should remind everyone again that the B1 is very balanced, so it should go without saying that the highs don’t overpower anything, or even feel bright. I just came from a treble roll-off amp and my ears don’t feel fatigued at all, even after 3 hours, if that helps. The highs sure are precise, though.

 

Coloration: None. Sound is very natural, and is as good as your source DAC/DAP, so however that’s supposed to sound you’ll get it.

 

Tonality: A warmer sound, though at no time muddy; the B1 stays extremely detailed for its price even with its warmth. It creates a very inviting and comfortable sound that you just want to sink into, though sacrificing a big soundstage.

 

Soundstage: Well-defined, although I do have to say it’s a tad on the smaller side, due to the B1’s warmth; but within the presentation it gives, it remains very 3D-like. I’m left satisfied, and frankly I’m fine with the way it is. Coupled with a big soundstage from the K7XX, it stays comfortably large, albeit not huge. With the KRK KNS-8400, it has no indication of being small though. So whether you want to use this with open-back headphones or closed-back ones, they’ll both sound wide enough for leg room.

 

Imaging: Well done; whatever the soundstage may lack, the imaging more than makes up for it. The components of the song are all around you, not only front and center, and I can tell where everything’s placed.

 

Separation: The separation would be the only non-strong point of the B1, if I had to pick one. The B1 is more of a musical amp than an analytical one. As such, components tend to blend together musically than staying completely separate where you can pick them out. However, due to the nature of the B1, this helps the amp stay musical and the music flow. This isn’t an analytical amp though, as I’ll mention soon.

 

Frequency shape: Flat, but doesn’t have a flat-ish sound. Every part of the spectrum is lively. Does that make sense?

 

Detail: Very detailed in highs, mids, and lows, I’m proud to say. I’m quite pleased with the amount of detail it presents overall. Detail is definitely one of the B1’s strongest points.

 

Accuracy: It’s hard not to love the accuracy the B1 provides, especially given its detail. Sound is fast and on point to my ears, and being both very accurate and detailed just makes the B1 a deadly competitor and a king in this department.

 

Balance: Also great; I wouldn’t have imagined that the sound sig could be the way it is without having something boosted in some way. But I have to say, the balance of this amp is near perfection, especially compared to the amps I’ve tried before. Definitely makes my K7XX and KNS-8400 sing.

 

Coherency & Flow: A very musical amp, this is the type that makes you want to sit back on your couch and sink in. It doesn’t sound unnatural though, and doesn’t blend in together too much. It flows just right to me.

 

Reveal Factor: The B1 is quite revealing, something that’s going to be coupled with any very detailed amp, I’m afraid. To illustrate, I was a bit shaken when I was hearing recording mistakes in my songs I had no idea existed, even with any of my other amps. However, feed it quality stuff, and it’s very rewarding.

 

Immersion Factor: I have to mention that this isn’t a very analytical amp in the sense that it sucks you in, so don’t expect to be paying attention to every little detail, because in the end, you’re going to space out and have to rewind. That’s why reviewing this is so darn hard; I have to listen to each song 3 times until I can finally pay attention to how good it is. That’s the immersion factor to you.

 

Sound Summary: It sings. That’s the best 2 words I can use to describe it. You won’t be analyzing your music anytime soon, as the B1 will invite you in and shut the door behind you, until you realize you’re not doing much analyzing and rewind back 3 songs later. Very musical, detailed, and 3d-like presentation, all the while keeping a steady coherency and flow that won’t leave you disappointed. The most important part of this review -the sound- the Aune B1 excels at, especially given that it’s a portable amp.

 

Value & Conclusion:

 

The B1 is a serious threat to other amps, even just given it’s features, which, let me remind you once more, is fully Class A in a portable package. Yet Aune didn’t stop there; the B1 excels at sound given its price range and looks wonderfully classy to boot. Quality heating control, and battery life is very decent given its specs. Size is in a great form factor, although the B1 is on the heavy side. Almost all definite positives, while having very little that there’s not to like.

 

I would recommend this completely to those who don’t want to be glued to wall outlets while powering heavy voltage-needy headphones at home, and also want an extremely potent portable amp for their daily travel with portable/closed-back headphones. For those looking for a sole IEM amp, I’m not sure why you would look at a Class A amp to begin with, but hey, it does well with those too.

 

All in all, the Aune B1 really packs a punch given everything it has going for it. If I had $200 to spend on a portable amp that could double for desktop headphones, I’d most certainly buy the B1 in a heartbeat. I couldn’t find anything wrong with it if I tried.

 

-Avishai

 

P.S. – the B1 sample I just reviewed is going on tour in a week or two; the application thread is open here http://www.head-fi.org/t/768275/aune-b1-usa-tour-application-thread for those that live in the U.S.A and want to give the B1 a try. Good luck!

 

Video review:

 



 

A few other Pictures (that didn't make it to the review):

 

Aune is the company with their own, unique approach to audio gear. Their products are unusual and offers interesting features, absent in competing solutions.

Their new headphone amplifier B1 looks like no other, and differs from other by its schematic. It utilises class A output stage built with discrete elements, and offers possibility to chose amplifier's current: 20 mA or 40 mA. Aune created nice page, describing B1 unique ideas, so I will not repeat them.

First of all, specs.

• Frequency range: 10 Hz – 20 KHz ± 0,15 dB
• THD+N: <0,0008% @ 1 KHz, 600Ω
• Signal/noise ratio: >124 dB @ 600Ω
• Channel separation: > 110 дБ @ 1 КГц, 600Ω
• Output power: 25 mW @ 16Ω, 50 mW @ 32Ω, 100 mW @ 300Ω
• Headphone impedance: 16Ω — 300Ω
• Battery: 4000 mA/h
• Life time: 10 hours for 20 mA, 5 hours for 40 mA
• Size: 65 mm × 110 mm × 18 mm
• Weight: 230 g

So, by size it's a little bit smaller than Fiio E12, but somewhat thicker.

B1 is sold in small box from black cardboard with silver print. It's similar with others Aune products and looks pretty stylish for $200 device. Besides amplifier you'll get small 3.5 mm cable and Micro USB cable for charging.

Aune B1 exterior is very stylish. It's built from solid aluminium, back panel have leather inserts on it. This protects devices from scratching, if you'll decide to make a stack with your smartphone or player. There are two color options available: black case with black leather and silver case with red inserts. Both look really cool.

On front panel designers placed transparent windows that allow you to see main feature of B1: discrete triodes output stage, working in class A. Really nice touch, like in swiss watch you can see device's complex interior. When B1 is turned on, two green LEDs are lightened inside. Not sure, if they are necessary, but they look great.

Major part of controls are located on left panel: power switch, gain switch and amplifier current selector (it's labeled "Class A").

On bottom, located charging micro USB, on top — volume control and input-output sockets. On right side there is button and LED, indicating remaining charge. Press button and count LED's flashes: 5 is 100% charge, 4 is 80% and so on.

Of course, the most interesting thing for amplifier is sound. And B1's sound is unusual. It's not as powerful as OpAmps solutions, but it still got enough power to drive almost all headphones with ease. It has almost black background, I didn't got any noise with all headphones I've tried. Discrete output stage allows B1 deliver really great amount of details, still remaining musical and pleasant sounding. B1 tries not to add anything to source's sound to preserve its natural form. Thus, if you need amplifier, boosting amount of bass, it's not B1. B1 adds more control and texture, but not amount.

Mids are lively and transparent. You'll get all emotions, present in record. Highs are detailed and delivered with confidence, but if your headphones/source are bright, you can get too much treble, as B1 doesn't hide anything.

Current switch is neat idea for power-hungry headphones. Boosting it to 40 mA reduces lifetime to 5 hours, but B1 drives headphones with mach more confidence: more tight bass, more transparent treble.

So, Aune made really interesting amplifier with great exterior and unusual schematics, delivering great sound.







I've made simple video, to showcase B1

[VIDEO]https://www.youtube.com/watch?v=k2NHszPLlqs[/VIDEO]