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Aune B1

Rating:
4.34211/5,
Tags:
  1. nmatheis
    Aune B1 Quick Review
    Written by nmatheis
    Published Aug 22, 2015
    3.5/5,
    Pros - Unique aesthetics. Powerful. Good soundstage and separation.
    Cons - Mid-centric. Plastic volume knob and switches don't inspire confidence. Too powerful for IEM.
    IMG_2352.jpg
     
     
    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!
    IMG_2375.jpg
    IMG_2376.jpg
     
     
    Open the box and you see the B1 and accessories.
    IMG_2377.jpg
     
     
    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...
    IMG_2378.jpg
     
     
     
    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.
    IMG_2345.jpg
     
     
    On the back, we see the micro USB receptacle.
    IMG_2346.jpg
     
     
    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...
    IMG_2347.jpg
     
    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.
    IMG_2348.jpg
     
     
    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.
    IMG_2353.jpg
     
    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!
    IMG_2351.jpg
     
     
    How big is the B1?  Just about the same footprint as my E12A but about half again thicker.
    IMG_2336.jpg
     
     
    Here's another view with the Shanling H3 thrown in for comparison.
    IMG_2333.jpg
     
     
    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!
      hakushondaimao likes this.
  2. LostInMyDream
    A bit of suprise...
    Written by LostInMyDream
    Published Aug 11, 2015
    3.5/5,
    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.
      aluweer likes this.
  3. miceblue
    A Solid "Portable" Amplifier for the Price, With a Unique Twist
    Written by miceblue
    Published Jun 14, 2015
    3.5/5,
    Pros - Overall aesthetics, sound quality, silent background, discrete Class A design, Class A switch sonic characteristics, voltage output, price
    Cons - Build quality, volume knob, not stackable, thickness, too much gain, current output, I/O placement, battery life, battery charge time, charge noise
    DSCN9285.jpg



    [rule]
    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



    [rule]
    Video Review


    0:16 - Thank you to Aune Audio
    0:41 - Sound quality A/B test methodology
    1:39 - B1 vs OPPO HA-2
    2:20 - B1 vs FiiO E12
    3:35 - B1 vs JDS Labs C5/C5D
    5:54 - B1 vs JDS Labs Objective 2
    7:53 - Sound quality overview
    8:36 - Price-sound quality value
    8:51 - Gain switch voltage output
    10:02 - Class A switch current output
    11:05 - Class A amplifier design overview
    11:41 - Battery life
    12:23 - Class A switch's sound
    14:05 - Aesthetics overview
    15:03 - Mute relay
    15:27 - Input/output overview
    15:42 - Volume knob
    16:43 - Front panel window and component overview
    18:52 - Size and portability
    20:24 - Stackability
    21:39 - Aluminum chassis overview



    [rule]
    There's not much in here:
    • Aune B1
    • Aune business card
    • B1 user manual
    • USB A-microUSB cable
    • 3.5 mm-3.5 mm straight interconnect

    I made a silent unboxing video on my YouTube channel if anyone is interested in it. It was made for ASMR purposes, so it'll be really weird to watch for 99.99% of the people reading this review.

    Video Table of Contents:
    4:30 - Box overview
    6:32 - Opening the box
    6:49 - Aune business card
    7:01 - B1 user manual (Chinese)
    7:25 - B1 user manual (English)
    7:55 - USB A-microUSB cable
    8:03 - 3.5-3.5 mm interconnect
    8:24 - B1 overview (I wanted the camera to focus on the component window, but it didn't work sadly; it's in the video thumbnail though)
    9:40 - Turning the B1 on
    10:25 - B1 size comparison with Nintendo 3DS



    [rule]
    I won't go into great detail here but I think the power output, size, mass, and battery life specifications are pretty important to know.
    Full details:
    http://en.auneaudio.com/html/en_products1/Portable_series/190_11.html

    Power output and derived voltage and current outputs from Ohm's Law:
    16250.63239.528
    32501.26539.528
    3001005.47718.257


    I received official confirmation from Aune themselves that the B1 outputs 3 Vrms in low-gain mode, 6.5 Vrms in high-gain mode at 1 kHz 0 dBFS signal.

    The maximum input signal into the B1 is 2 Vrms.


    Size:
    • 65 mm (width)
    • 110 mm (height)
    • 18 mm (depth)

    Mass: 230 g

    Battery Life:
    • 10 hours while operating in the 20 mA mode
    • 5 hours while operating in the 40 mA mode



    [rule]
    Classes of amplifiers are determined by how the amplifying transistors are biased (with current). Class A amplifiers always have the amplifying transistors always on and always biased. The amplifying transistors are thus never turned off and are always active whether or not there is a signal to be amplified. Because of this, they are extremely inefficient in terms of power management, and that's why they tend to get warm due to energy being dissipated as heat.

    Two advantages for this kind of amplifier design though is that it's extremely responsive since the amplifying transistors don't need to have a wait period between turning on/off, and it's extremely linear. Class A amplifiers have the ability to amplify a signal linearly with little distortion as long as they are properly biased to operate in the linear region.

    The Class A switch of the B1 alters the static current, or Class A bias. Of course demanding a higher, always-on, current correspondingly affects the current draw from the battery, and thus lowers the battery life. No surprises there. I also don't think it's just coincidence that the highest current output of the B1 is also the number for the high-current mode, 40 mA.



    [rule]
    The overall aesthetics of the B1 are simply stunning in my opinion. An all-metal chassis, viewing window to see the interior PCB and discrete components, and synthetic leather on the back all make it look very impressive.
    DSCN9264.jpg

    DSCN9227.jpg



    The term "discrete components" just denotes basic electronic parts with no special integrated circuit components such as operational amplifiers (op-amps). The Class A amplifying circuit is built entirely out of these individual transistors and no op-amps are used.
    DSCN9208.jpg

    DSCN9216.jpg
    ^ the black rectangular pieces with 3 solder joints are transistors

    Also used in the B1 are round, no-lead, MELF resistors, which is relatively unheard of for an amplifier in this price bracket (to my knowledge).
    More information here:
    https://en.wikipedia.org/wiki/Metal_electrode_leadless_face
    DSCN9306.jpg

    DSCN9294.jpg


    Although the overall aesthetics are really good, the build quality itself is a bit lacking to me. For one, the volume knob, which appears to be silver and suggests that it's made of metal like the chassis, is in fact plastic. The feel of the knob is very lame too. It's hard to grip, there are no volume indicators on it, and it seems to have variable resistance when turning (becoming easier and harder to turn depending on how far it's turned). It's definitely not the kind of quality I expected upon seeing it for the first time and it's underwhelming to adjust.
    DSCN9259.jpg

    DSCN9261.jpg


    The input/output ports of the B1 are poorly placed relative to the volume knob, especially with 90˚-angled jacks. Yeaaaaaaaaaaaaaaaaaah......good luck with that!
    DSCN9396.jpg

    DSCN9410.jpg
    ^ portable rig = ruined and unusable


    Just like the volume knob, the switches themselves are plastic and feel a bit cheap on the otherwise really nice chassis.
    DSCN9265.jpg

    DSCN9303.jpg

    DSCN9302.jpg


    The synthetic leather itself is just a sticker, and the edges are roughly cut upon closer inspection.
    DSCN9272.jpg


    Although the chassis is made of a single piece of aluminum, this aluminum also appears to be pretty soft. I don't recommend taking the B1 with you if it has the risk of falling onto a hard surface. I had the B1 on top of a piece of paper on my desk and the paper got moved by accident. *Thonk* The B1 fell on top of a glass table lamp I have nearby and the edges of the metal chassis got pretty banged up. The metal is now sharp at the edge and I am not going to stack anything scratch-sensitive on top, or underneath it. The glass lamp is fine though.
    DSCN9445.jpg

    DSCN9446.jpg

    : (


    Speaking of stacking things on top or below the B1 though, the package contents don't contain any adhesive rubber feet, nor silicone bands. Without those, you really have no viable options for stacking things on top or below the B1, which is unfortunate. The front face/top of the B1 is all aluminum with only the two glass windows. I ain't going to stack any metal or glass objects on top of that. On the back/bottom of the B1, it's basically all aluminum too with the synthetic leather inserts providing basically zero millimeters of padding between the B1 and the adjacent surface. I ain't going to stack any metal or glass objects underneath that either. For most of my time with the B1, I've been stacking the it on top of my OPPO HA-2 since the real-leather cover of that won't get easily damaged, and it provides some height to wrap my fingers around the volume knob to actually grip and turn it. I am most certainly not going to put the B1 in my pocket attached to a DAC/portable media player in fear of getting them scratched to death.
    DSCN9268.jpg



    As for the heat it gives off, it's really nothing worth mentioning, seriously. Yes, it's a Class A amplifier. Yes, it's extremely energy inefficient. No, the 40 mA current mode isn't going to get super hot. My iPhone 4S gets hotter than it when watching a YouTube video, so don't even worry about heat.


    Regarding power, the B1 might not have as much power output compared to other portable headphone amplifiers. However, I don't think power is really an important thing to use for a determination of sound quality unless you actually need 100+ mW for headphones. I used the 688 Ω AKG K240 Monitor, as measured by Innerfidelity for my specific unit, with the B1 on low-gain just fine. Taking into account my listening preferences, low-gain mode makes absolutely perfect sense for how I listen to music. It takes 0.447 Vrms at 688 Ω for my K240 Monitor to reach 90 dB SPL. My average listening volume is somewhere between 70-80 dB SPL as determined by a calibrated audio system from a local meet. I take into account +25 dB peak requirements from music as headroom for an amplifier, which makes the peak requirements 95-105 dB SPL. Indeed, calculating out the power requirements for the K240 Monitor, it would need 2.514 Vrms, 3.654 mA, or 9.184 mW to reach 105 dB SPL, all of which are perfectly within the B1's 3 Vrms output in low-gain mode as well as 20 mA Class A mode. For a low-impedance headphone that's relatively insensitive such as the HIFIMAN HE1000 on the other hand, the B1's limited current output starts to make the power output relevant since its cap is 40 mA.

    The gain switch affects voltage output; the Class A switch affects the current output. I find the low-gain output to have too much gain even still. I can barely use the volume knob for sensitive headphones like the OPPO PM-3, and I would say the volume knob is useless for in-ear earphones. I personally wouldn't recommend the B1 for these cases because it's simply just too loud. The volume knob has the typical channel imbalance at low levels, and then gradually diminishes as the knob is turned further. By the time I get past the channel imbalance region for the MEElectronics M9, even quiet music is too loud for me in a home environment. This is just unacceptable to me and it makes normal, non-quiet, music unlistenable at a comfortable volume level.


    Regarding the battery life, 9 hours for a portable headphone amplifier is on the low-side from what I've seen. If you're planning to use the B1 portable amp as a, well, portable amp, I would have liked to see at least 10 hours. Five hours in the 40 mA mode is even more of a setback, but I personally don't like the sound out of the 40 mA mode and I wouldn't use it anyway (more on this in the "Sound Quality" section below).

    Charging time for the B1 is also pretty slow. From 0-100%, I clocked in roughly 4 hours' worth of time while using a microUSB-USB A cable to my MacBook. That's a long time to charge a portable amplifier and if I want to use it as a portable amplifier, I would have liked to see a 2-3 hour charge time instead.

    While the B1 is charging, the device has an audible noise problem. It's audible with in-ear earphones, as well as full-size headphones like the HIFIMAN HE1000. It sounds like a fluttering/buzzing sound and it's pretty annoying. Trying it with different USB ports reveals that it's dependent on the connection. Through a normal USB-hub, the noise is audible even at low volume levels. Through my MacBook's USB ports, the noise is only audible when the volume knob is turned up. Through the LH Labs Linear Power Supply 4, the noise is pretty minimal. On high-gain, the noise is definitely amplified, no questions asked.


    In terms of its size, I think the B1 is way too thick to be consider portable, hence why I have "Portable" in quotes for my review title. It's nearly as thick as my Nintendo 3DS handheld gaming console and I already consider that to be a huge burden to carry around in my pocket since it's also smartphone-sized in terms of length and width. Carrying around a Nintendo 3DS-sized metal brick on top of a portable media player or other source prevents the B1 from being portable in my honest opinion. To me, it's more transportable than portable.
    DSCN9233.jpg

    DSCN9429.jpg

    DSCN9438.jpg





    So...yeah, the build quality and some of the design elements are things to be desired in my opinion, hence why I gave the Quality and Design ratings 3.5/5 and 3/5 respectively. It's good enough for the job, but I feel that a lot of things could be improved upon for future consideration.



    [rule]
    Overall, the B1 sounds pretty good to me! There are two things main things about the B1's sound that I experienced:
    1. I prefer the sound from the 20 mA mode over that of the 40 mA mode
    2. It compares favourably next to other portable and transportable amps I have at hand

    An overview of how the B1 in general sounds to me:
    • Slightly woolly-sounding bass
    • Slight warmth in the bass/lower-midrange area
    • Slight etch or emphasis in the upper-upper-midrange area (4-6 kHz-ish)
    • Treble roll-off
    • Wider-than-deep soundstage
    • Good, but not great, instrument separation
    • No background hiss

    Again, these impressions are all with the low-gain mode because I find low-gain to offer plenty of voltage for my listening preferences, let alone usage of the volume knob.

    I did a ton of listening sessions between the 20 mA and 40 mA modes. At first, I hardly heard a difference between the two modes. I was thinking maybe the 40 mA mode had a larger soundstage, but I would be pulling strings to say I would be able to pass a blind test with it. Those listening tests were done with just a DAC and the B1. Aune specifically recommends not adjusting the current switch when the B1 is in operation, so I would listen to the B1 in one mode, turn it off, switch the Class A switch, and turn it back on. The time it took to do that process probably skewed the results.

    I later did A/B tests against other amplifiers while using the FiiO HS2 as a switch and I was able to more reliably, and accurately, hear a difference between the two modes. In summary:
    20 mA mode:
    • Slight warmth in the bass/lower-midrange area
    • Wide soundstage, little depth
    • Decent center imaging

    40 mA mode:
    • More warmth, and a slight sub-bass boost
    • Wider soundstage, more depth
    • Lack of center imaging

    It is because of the better center imaging that I prefer the 20 mA mode over the 40 mA one. The 40 mA mode reminds me of the AKG K 701's infamous soundstage and imaging abilities: much wider-than-deep soundstage and a lack of a center image. It just sounds plain weird to me. However, you may prefer that kind of sound, so your mileage may vary.

    Were I to blind test the 20 mA and 40 mA modes now that I have a better understanding of how they sound with an A/B switch, I'm pretty confident I would be able to pass it just because the weird center imaging of the 40 mA mode was so strange-sounding to me.



    Now, against other portable headphone amplifiers I have at hand, the B1 stacks up pretty well against them. All of these tests were volume-matched by ear with pink noise and 1 kHz sine wave signals generated from Audacity. I toggled between the 40 mA and 20 mA modes for these tests too, so the following impressions are more or less an average of what I heard. I still prefer the 20 mA mode though.
    DSCN9383.jpg

    Setup:
    • MacBook Pro + Audirvana Plus 1.5.12 (hog mode, integer mode, no upsampling)
    • LH Labs Linear Power Supply 4 for a clean USB power source
    • Objective DAC + RCA outputs
    • Y-splitter to go into two amplifiers
    • B1 and other amplifier to compare to
    • Outputs of amplifiers to HS2
    • Headphone of choice

    Headphone of choice included any of the following, and I did tests with all of them for each amp comparison:
    • AKG K240 Monitor (high impedance, low sensitivity, voltage-demanding)
    • AKG K701 (medium impedance, low sensitivity, current-demanding)
    • HIFIMAN HE1000 (low-impedance, low sensitivity, current-demanding)
    • OPPO PM-3 (low-impedance, high sensitivity, current-demanding)

    FiiO E12 (~$129 USD) vs B1:
    • E12 sounds grainier
    • E12 sounds much brighter and harsh
    • E12's bass sounds more woolly
    • E12's soundstage seems much more narrow in width
    • E12's instrument separation is much more blurred
    Hands down I would pick the B1 over the E12, no questions asked.

    JDS Labs Objective 2 ($130) vs B1:
    • O2 sounds smoother
    • O2 has better treble extension
    • O2 has better bass control
    • O2 doesn't have upper-upper-midrange emphasis
    • O2's soundstage is more rounded overall
    • O2 has more rounded imaging abilities
    • O2 has better instrument separation
    It's a tough call for me. I do like the B1's wider soundstage since it gives the illusion of a larger room in width, but I think the O2 would technically be a better amp sonically overall.

    JDS Labs C5 ($189) (in my case I used the C5D since it has a lower output impedance from my older C5 unit, but the amplifier is exactly the same other than the bass boost switch which I didn't toggle) vs B1:
    • C5 sounds slightly smoother
    • C5 has better treble extension
    • C5 has better bass control
    • C5 sounds brighter in the typical 2-4 kHz area versus the 4-6 kHz region of the B1
    • C5's soundstage is more limited in width
    • C5's center imaging is much better
    • C5 has better instrument separation
    Again, it's a tough call for me. I might give the B1 a slight upper-hand here because it doesn't have the bright sound of the C5, but at the same time, I do like the C5's instrument separation and center imaging more.

    OPPO HA-2 ($299) (keep in mind that this is a DAC and amp, so you get more for your money there) vs B1:
    • HA-2 has better bass control
    • HA-2 has better treble extension
    • HA-2 has better instrument separation
    This was by far the hardest test for me. On the 20 mA mode, the two sounded basically identical to me. The B1 might have had a little more warmth, but it was really hard to hear reliably. I give the upper-hand to the HA-2 in this case due to the better treble extension on the other hand.


    All in all, this was a pretty interesting testing session. It's been commonly accepted that Class A amplifiers "sound the best" amongst amplifier classes. This may be true, or may not be true. The design of the amplifier is of the most importance to me though, not the class. Obviously I think the O2 overall sounds better than the B1 in a technical sense, and the O2 is a Class D amplifier that uses operational amplifiers. The OPPO HA-2 sounded nearly identical to the B1 and it uses a Class AB architecture.



    [rule]
    Pros:
    • Great sound
    • Unique internal design of discrete components and Class A architecture
    • Class A switch might be worth experimenting with for various headphones
    • Excellent voltage output
    • Fairly competitive price

    Cons:
    • Slightly low battery life
    • Disappointing, but overall okay build quality
    • Some pretty important design flaws that could be remedied

    A thumbs up from me for sound quality by itself at its price point, but a thumbs down for practical use (as a portable device) and overall shortcomings of the design and build quality.



    Thank you again to Aune for letting me have this opportunity to listen to the B1 with my own setup for these past two weeks. It's been a fun learning experience for me and I look forward to seeing what products you release in the future!

    As always, thank you for taking the time to peruse through my review and I hope you got a thing or two out of it.


    DSCN9419.jpg
    1. View previous replies...
    2. Peter West
      Don't know where my last message came from re text editor...sorry about that...

      I'm reviewing the B1 right now and I'll post in a couple of days. We may have to agree to disagree on some points. The B1 really makes my LCD-X come alive especially when compared to my more laid back Picollo amp. Haven't got to testing out my in-ears yet. So far I'm very impressed.
      Peter West, Jun 26, 2015
    3. miceblue
      That's why we have multiple reviews for a product!
      I tried to make my review as objective as possible without directly measuring anything, and I made numerous comparisons between other amps and other headphones of varying impedances and sensitivities with those amps.
      miceblue, Jun 27, 2015
    4. hqssui
      Excellent review . Thanks a lot..
      hqssui, Aug 11, 2016
  4. bhazard
    A very good Class A portable amp
    Written by bhazard
    Published Aug 18, 2015
    4.0/5,
    Pros - Sound, Build Quality
    Cons - Low battery life, Large.
    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.
  5. derGabe
    Der B1 ist ein potenter Kopfhörerverstärker mit geringen Schwächen im Design
    Written by derGabe
    Published Jul 12, 2015
    4.0/5,
    Pros - genug Leistung für die meisten Kopfhörer
    Cons - Kanalschwankungen im untersten Lautstärkebereich, Schwächen im Design
    AUNE B1 / Portable Headphone Amplifier


     
    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.

      thelonious58 likes this.
    1. derGabe
      This is the German Review for the Aune B1. An english Version is coming in the next Days.
      derGabe, Jul 12, 2015
    2. Wildcatsare1
      Thank you, my German is a bit rusty!
      Wildcatsare1, Jul 13, 2015
    3. h1f1add1cted
      Haha ich dachte ich lese nicht richtig, ein deutsches Review auf Head-Fi :) Hättest auch gerne z.B. im Hifi-Forum berichten können, aber dennoch danke. Mich würde das Grundrauschen vom B1 interessieren, gab es da keins mit dem StageDiver 2?
      h1f1add1cted, Aug 5, 2015
  6. ClieOS
    Full Discrete Class A portable amplifier
    Written by ClieOS
    Published Jun 13, 2015
    4.0/5,
    Pros - Sound Quality, Build Quality, Price.
    Cons - High Output Impedance, Short Battery Life, Relatively Low Output Power.
    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?
     
    [​IMG]
     
    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
     
    [​IMG]
     
    [​IMG]
     
    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.
     
    [​IMG]
     
    [​IMG]
     
    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.
     
    [​IMG]
     
    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.
     
    [​IMG]
     
    [​IMG]
     
    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
     
    [​IMG]
    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
      zhibli06 and money4me247 like this.
    1. View previous replies...
    2. Evshrug
      Nice review! Sounds appealing, though for something high-quality portable like this to NOT suit equally high-quality portable like the higher-end IEMs with 3-12 drivers does seem to be a head-scratcher. Good that it breathes new life into the classic Etymotic though!
      Evshrug, Jun 14, 2015
    3. AuneAudio
      Hello , thanks for the good review , we will upgrade  the headphone impedance in the next version of B1 , thanks 
      AuneAudio, Jun 15, 2015
    4. ClieOS
      Good to know. While under 1 ohm will be great, I think anything under 2 ohm will be good in my book.
      ClieOS, Jun 15, 2015
  7. creatip
    A little amp with class
    Written by creatip
    Published Jun 7, 2015
    4.0/5,
    Pros - Very stylish and elegant, good sound, long running time, good value for the price
    Cons - A bit big, gets warm with use
    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
     
    IMG_0669_zps5ua4onng.jpg
     
    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. 
     
    IMG_0679_zpsidc5gqq7.jpg
     
    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.
     
    IMG_0717_zpsr7b82xlg.jpg
     
    IMG_0774_zpsvwvxz0ie.jpg
     
     
    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.
     
    IMG_0816_zpsvrol3pi4.jpg
     
    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. 
     
    IMG_0804_zpslxu83vdr.jpg
     
    IMG_0834_zpsg3g007fk.jpg
     
    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.
     
    IMG_0805_zpsbhxhut7f.jpg
     
    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%.
     
    IMG_0807_zpsrtuaeiiz.jpg
     
    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.
     
    IMG_0809_zpsc7mq0bjj.jpg
     
    On the bottom side, there's a micro USB input for charging. 
     
    IMG_0739_zpspcbqofvi.jpg
     
     
    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:
     
    [​IMG]
    *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...[​IMG] 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
     
    IMG_0823_zpsi47ntmhn.jpg
     
    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. 
     
    IMG_0759_zpssdqcplp8.jpg
     
     
    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. 
     
    IMG_0829_zpsrocaudwj.jpg
     
    The 'siblings', T1 tube DAC/amp and the B1 Headphone amp. Zippo for size.
      aluweer and Synthax like this.
  8. money4me247
    Unique Affordable Portable Amplifier with Clean Sound
    Written by money4me247
    Published Jun 3, 2015
    4.0/5,
    Pros - great value, stylish design, versatile, clean sound signature & solid SQ, unique topology/design as fully discrete Class A portable amp
    Cons - amplifier only, larger & weight size compared to some competing portable amplifiers (Class A/B), lack of accessories, room for design improvements
    Aune B1 portable headphone amplifier Review
     
    2015-06-0219.58.09redsidecropped.jpg
    1. Review unit provided by Aune during its worldwide review tour. Link to program details here
    2. Extensively tested over a period of more than full week (with an extended out-of-town trip)
    3. Will continue to use the B1 for the remaining one week period allocated for the review sample & will update this review as needed
    4. ***UPDATE 6/10/15: I have shipped out the B1 review unit on a USA demo tour (sign-up here)
    5. This is an unpaid and uncensored review covering my own personal subjective thoughts and opinions. I am NOT a professional reviewer. As always, I hope this is an enjoyable and informative read, and remember that ymmv!
     
    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.
     
    2015-06-0219.08.57blackshadowcropped.jpg

    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.
     ​
    2015-06-0220.05.50redleather.jpg
    Aune B1 Leather Side
     
    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.
     
    2015-06-0218.59.12blacktopedgesideshot.jpg
    Top View of the B1 (minus sign obscured by the glare)
     
    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.
     
    2015-06-0220.00.52switchside.jpg
              ​
    2015-06-0219.00.35blacktopedge.jpg           
    2015-06-0220.00.20batside.jpg
       B1's Left Side with switches                   B1's Top Side with volume control        B1's Right Side with battery indicator
     
    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.
     
    2015-06-0219.58.58redglowslash.jpg
          ​
    2015-06-0220.06.21rednoglow.jpg
     ​
    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.
     ​
    2015-06-0219.05.31blackwires.jpg        2015-06-0219.05.54blackwindowswires.jpg
    B1's leather side while connected to source                             
    B1's window side while connected to source​

     
    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.
     
    2015-06-0220.03.14ha2vb1front.jpg
    Size Comparison between the Aune B1 vs Oppo HA-2
     
    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.
    2015-06-0220.11.34-redglowcropped.jpg

     
    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.
    I decided to use a sampling of currently popular songs from the Billboard top charts as test tracks in addition to my usual test tracks. Covers a wide variety of genres. My list of usual test tracks can be found in my other reviews. List split by genre and ordered alphabetically by artist
     
    Alternative: “Uma Thurman” by Fall Out Boy, “Renegades” by X Ambassadors
    Asian Pop: “Haru Haru” by Bigbang, “Adoration” by David Tao, “Tornado” by Jay Chou, “If Only” by JJ Lin, “The Third Person And I” by Jolin Tsai, “Love Song” by Rain, “Wedding Dress”“by Taeyang, “Heartbeat” by Wang Lee Hom
    Classical: The following is all performed by London Philharmonic Orchestra and recorded by Abbey Road Studios, Royal Festival Hall, and Henry Wood Hall. “Adagio for Strings” by Barber, “Bagatelle In A Minor, WoO 59, Für Elise” by Beethoven, “Nocturne No. 2 In E-Flat Major, Op. 9” by Chopin, “Suite bergamasque, L 75: Clair de Lune” by Debussy, “Symphony No. 5: Adagietto” by Mahler, “The Magic Flute, K. 620: Overture” by Mozart, “Canon In D Major” by Pachelbel, “Finlandia, Op. 26” by Sibelius, “The Four Seasons, Op. 8, Spring: Allegro” by Vivaldi, “The Valkyrie: Ride of the Valkyries” by Wagner
    Country: “Smoke” by A Thousand Horses, “Little Toy Guns” by Carrie Underwood, “Say You Do” by Dierks Bentley, “Sippin’ On Fire” by Florida Georgia Line, “Wild Child” by Kenny Chesney, “Girl Crush” by Little Big Town, “Take Your Time” by Sam Hunt, “Diamond Rings And Old Barstools” by Tim McGraw
    Electronic: “Waiting for Love” by Avicii, “Outside” by Calvin Harris, “Get Low” by Dillon Francis & DJ Snake, “Love Me Like You Do” by Ellie Goulding, “Lean On” by Major Lazer & MO, “I Want You To Know” by Zedd
    Jazz: “I Didn’t Know About You” by Duke Ellington, “Blue Train” by John Coltrane, “The Dreamer” by Jose James, “Songbird” by Kenny G, “There WIll Never Be Another You” by Lester Young, “What A Wonderful World” by Louis Armstrong, “So What” by Miles Davis
    Folk: “Thinking Out Loud” by Ed Sheeran, “Budapest” by George Ezra
    Funk: “Uptown Funk” by Mark Ronson & Bruno Mars
    Indie Rock: “Shut Up and Dance” by Walk the Moon, “Geronimo” by Sheppard
    Pop: “I Really Like You” by Carly Rae Jepsen, “Heartbeat Song” by Kelly Clarkson, “All About That Bass” by Meghan Trainor, “Fight Song” by Rachel Platten, “American Oxygen” by Rihanna, “Elastic Heart” by Sia, “Bad Blood” by Taylor Swift
    R&B: “One Last Time” by Ariana Grande, “I Bet” by Ciara, “Worth It” by Fifth Harmony, “Want to Want Me” by Jason Derulo, “Nobody Love” by Tori Kelly, “Slow Motion” by Trey Songz, “Earned It” by The Weeknd
    Reggae: “I Need Your Love” by Shaggy
    Rap & Hip Hop: “Energy” by Drake, “Trap Queen” by Fetty Wap, “GDFR” by Flo Rida & Lookas & Sage, “Be Real” by Kid Ink & Dej Loaf, “Time of Our Lives” by Pitbull & Ne-Yo, “See You Again” by Wiz Khalifa & Charlie Puth
    Rock: “Bright” by Echosmith, “Sugar” by Maroon 5, “Believe” by Mumford & Sons
    Trap: “You Know You Like It” by DJ Snake & AlunaG
    Soul: “Honey, I’m Good” by Andy Grammer, “Take Me To Church” by Hozier, “FourFiveSeconds” by Rihanna & Kanye West & Paul McCartney
    Soundtrack: “Skyfall” by Adele, “My Heart Will Go On” by Celine Dion, “Atlas” by Coldplay, “Accidentally in Love” by Counting Crows, “Tron Legacy” by Daft Punk, “Will Hunting Main Title” by Danny Elfman, “Let It Go” by Demi Lovato, “I See Fire” by Ed Sheeran, “Lose Yourself” by Eminem, “May It Be” by Enya, “Aggressive Expansion” by Hans Zimmer, “Concerning Hobbits” by Howard Shore, “Spirited Away - One Summer Day” by Joe Hisaishi, “Star Wars Main Theme” by John Williams, “I See the Light” by Mandy Moore & Zachary Levi, “The Godfather Love Theme” by Nino Rota, “Everything Is Awesome!!” by Tegan & Sara & the Lonely Island, “I Will Always Love You” by Whitney Houston


     
    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.
     
    2015-06-0218.58.43blackside.jpg
     
    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!!!
    *********************************
     
    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.
     
    2015-06-0220.03.48b1vha2side.jpg          2015-06-0220.05.05ha-2vb1top.jpg
    Oppo HA-2 vs Aune B1 Side View                                                 Oppo HA-2 vs Aune B1 Top View

     
    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.
    Fiio E6 ($27.99)
    JAD Labs cMoyBB v2.03 ($59)
    Fiio E10k ($75)
    Creative Sound Blaster ($49.99)
    Fiio E11k 2 ($59)
    Fiio E12 ($129)
    Cayin C5 ($159.99 on Amazon, MSRP $239)
    JDS Labs C5 ($189)
    HeadAmp Pico ($349)
    Ray Samuels Audio Emmeline P-51 Mustang ($375)
    Ray Samuels Audio Emmeline Hornet ($370)
    HeadAmp Pico Slim ($399)
    Ray Samuels Audio Emmeline SR-71A ($450)
    HeadAmp Pico Power ($475)
    **Just Audio AHA-120 (~$535 in 2013, discontinued): fully discrete Class A portable amplifier
    Fostex HP-V1 tube amplifier ($549)
    Cypher Labs Algorhythm Duet ($599)
    iQube V5 ($699)
     
    **Note: Just Audio AHA-120 is a discontinued portable Class A amplifier using fully discrete components with a slightly different feature set that retailed at the $500+ price point.
    Do note that if you are looking for a compact external amplifier/dac, the B1 will not suit your application.
    Fiio E07k Andes ($89 on Amazon - MSRP $99.95,)
    Fiio E17k Alpen 2 ($139.99 on Amazon - MSRP: $249.99,)
    Fiio E18 Kunlun ($159 on Amazon - MSRP: $299.95)
    Creative Sound Blaster E5 ($199.99)
    Leckerton UHA-4 ($199)
    Beyerdynamic A200p ($219.99 on Amazon - MSRP $349)
    JDS Labs C5D ($249)
    Leckerton UHA-6S MKII ($279)
    Oppo HA-2 ($299)
    Sony PHA-1A ($299)
    Leckerton UHA760 ($399)
    Fostex HP-P1 ($449 on Amazon - MSRP $799)
    Sony PHA-2 ($449.99 on Amazon - MSRP $599.99)
    iFi Audio micro iDSD ($499)
    CEntrance Mini-M8 ($599.99)
    Centrance HiFi-M8 ($699)
    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***
     
    2015-06-0219.11.09woodglow.jpg
     
    Product link: http://en.auneaudio.com/html/en_products1/Portable_series/190_11.html

      aluweer, CPhoenix, Anjolie and 6 others like this.
    1. View previous replies...
    2. WhiskeyJacks
      I had never even heard of this, when did it come out?
      WhiskeyJacks, Jul 24, 2015
    3. money4me247
      @WhiskeyJacks, I am not 100% sure the exact release date, but it came out this year. Earliest thread discovering the B1 on head-fi is here (1/21/15). First head-fi review written by @cleg (2/14/15). Aune's official sponsored thread posting on the B1 here (4/8/15). Aune's head-fi review tour announced here (5/10/15) with an impression thread created here on 5/21/15.
      money4me247, Jul 25, 2015
    4. yacobx
      excellent review!
      yacobx, Mar 6, 2017
  9. Army-Firedawg
    Small powerhouse that provides tube like sound and musicality but with the ease of use of a solid state.
    Written by Army-Firedawg
    Published Apr 3, 2016
    4.5/5,
    Pros - Amazing sound and build quality
    Cons - Aluminum strip on the back can lead to scratches, un-indicating indicating light for the battery
         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. 
     
    I'm a 25 year old firefighter currently for the U.S. Army North Carolina National Guard. I was formerly a civilian firefighter in Kentucky with the Millard Fire Department before I enlisted and moved to my current location in Charlotte, North Carolina. My current goal is to begin my career again in the civilian fire service, and yes, I am the cliché of wanting to do that since as far as I can remember.
        My interests/hobbies are powerlifting, fishing and relaxing to audio products and reviewing them to help other decide on what products would work for them. On that note over the years I've really came to an understanding of what it is I like and look for in audio products.
        What I look for is a relaxing, warm and sensual sound that just drifts me away in the emotional experience of the music being performed. Yes, accuracy is still important but I will happily sacrifice that if I'm presented with a clean, warm sound that can wisp me away into an experience that makes me yearn for more.
        My ideal signature are that of respectably forward mids and upper bass range with the bass being controlled but with some slight decay. I like my treble to have great extension and detail reveal but I don't like artificial treble in order to achieve that. Examples of products that have given me chills and keep giving me the yearning for more feels are the Bowers & Wilkins P7, Oppo PM-1/2, Empire Ears Hermes VI, Audeze LCD-XC, Meze Headphones 99 Classics & Stax SR009.
     
     
                    20160325_212024.jpg
     
    20160325_212044.jpg
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    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.
     
    20160325_211422.jpg     20160325_211555.jpg      20160325_211616.jpg      
     
     
     
     
    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?
     
                                                                                                  20160325_211922.jpg
     
     
    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.
     
                                                                                      20160325_211538.jpg
     
     
    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.
     
     
     
      thelonious58 and thejammonster like this.
    1. View previous replies...
    2. emrelights1973
      Will it be good addition to zx2 euro for driving sony z7? 
      emrelights1973, Apr 6, 2016
    3. Army-Firedawg
      @emrelights1973 Though I've personally not tried either of those two, I don't see any reason why it shouldn't. On high gain it drove my HD650's with ease
      Army-Firedawg, Apr 7, 2016
    4. Hi-Fi'er
      This is a pretty bad ass amp. It's my new best portable amp. It rivals my other top end portables for way more than half the cost.
      Hi-Fi'er, Apr 11, 2016
  10. Buhagim
    Who says retro style impacts sound quality? Think again, Aune have bags of both with this stunning little performer
    Written by Buhagim
    Published Jun 8, 2015
    4.5/5,
    Pros - Transparent - deathly silent, built for being thrown around. Class A amp with a 10 hr. battery. Enhances smartphone audio experience
    Cons - Limited accessories. USB can't charge smartphone - only charges the B1. Volume knob needs a mark to show degree of rotation. No case or rubber bands.
    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)

    D71_2585-001.jpg D71_2587package.jpg
     
    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. 
    D71_2607-002hipflaskshape.jpg
    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
     
    [​IMG]
    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)
     
    D71_2691-001hipflask1.jpg D71_2687-001hipflask2.jpg
    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.
    D71_2613-002circuitwindow.jpg
    Close up of the circuitry through one window. (Click for larger file)
    D71_2684usb.jpg D71_2650volumeknob.jpg
    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.
     
    D71_2653-002batteryindicator.jpg D71_2654-001gaincontrols.jpg
    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:
     
    D71_2683-001MDACandSonos.jpg D71_2667-001.jpg
    Sonos played through MDAC and TIDAL played through Samsung S3 , B1 and NAD Viso HP50's.
     
    D71_2657NADandAUNE.jpg
    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 [​IMG] 
      aluweer and nick n like this.
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    2. money4me247
      enjoyed reading your review. great selection of test tracks with Mahler! :) love that song!
      money4me247, Jun 13, 2015
    3. avitron142
      Nice review! Well done!
      avitron142, Jun 13, 2015
    4. Buhagim
      Thanks guys. Appreciate your feedback
      Buhagim, Jun 14, 2015