Quick Read Conclusion
The Aune B1s ("
B1s") is a head turning pocket amplifier very well suited to more sensitive headphones, including IEMs that benefit from a little more oomph and a low noise floor. Although it makes a lovely, warm sound it is hard to recommend without question because it suffers from mobile phone interference, and does not drive that loud. An IEM only amplifier is a niche offering!
Introductions and General Bumf
Test Kit: I have tested the B1s with Shure SE215, SE425, Sennheiser HD600, Ultimate Ears UE900s, Campfire Audio Polaris and KEF M500 headphones/IEMs. As input sources, I hooked the B1s up to a Schiit Modi 2, iFi iDSD Nano BL, Samsung Galaxy S8, Note 8, Pioneer XDP-30r and an Astell and Kern AK70.
Preparation: I did not give the B1s any burn it, but as I was about the fifth person on the tour to use it, I figure it should have had a decent burn in by the time it got to me. It gets reasonably warm in operation, so I always gave it an hour or so to warm up before trying to listen critically.
Me as a listener: I am not a pro by any stretch of the imagination. I have always enjoyed my music, and my tastes are pretty broad. I go to live music ranging from rock and pop concerts to orchestra and opera. I would not describe myself as having a trained ear, but I am attentive and my ears are in pretty good nick for a 34 year old.
My tastes: neutral to warm, but I do like good punchy bass and I love to hear decent instrument separation.
Test tracks: I've tried to keep it broad and I have cited my music sources below, so (where possible) people can download the tracks themselves.
1) Wiz Kalifah – On My Level (320k MP3, Google Store)
2) Norah Jones – Turn Me On (24/192 FLAC, Qobuz)
3) John Williams – Throne Room from Star Wars performed by Prague Philharmonic Orchestra (16/44.1 FLAC, Qobuz)
4) The Verve – The Drugs Don’t Work (16/44.1 self-ripped FLAC)
5) Ed Sheeran – Castle on the Hill (320k MP3, Google Store)
6) JS Bach – Brandenberg Concertos, 1 (allegro) (16/44.1, self-ripped FLAC)
7) Hilltop Hoods ft. Sia – I Love It (256k m4a, iTunes)
8) 30 Seconds to Mars – Stronger (Radio 1 Live Lounge Cover) (16/44.1, self-ripped FLAC)
9) Pearl Jam – Yellow Ledbetter (320k MP3, Google Store)
10) Rage Against the Machine – Wake Up (292k m4a, iTunes)
Disclaimer: The B1s was temporarily provided to me for review, as part of the European tour organised by @tenedosian. I am in no way affiliated with Aune and have received no inducement to provide this review (other than the chance to participate in the tour).
So, on to the main event. [/General Bumf]
Unboxing
This is another premium experience. Well packaged in good quality, thick card, the Aune B1s is an absolute treat to open. From popping off the lid, you are greeted by a warranty cards and instruction card, followed by the amplifier itself (packed in matte effect plastic covering). The box I received had already been opened and as a result, the included 3.5mm male to male cable, usb charging cable and rubber rings were sent to me in a separate bag. I presume in the original retail boxing, these are packaged below the main unit.
I didn’t bother with the included 3.5mm cable, much preferring a sturdier Fiio cable I bought myself on amazon a while ago. In particular, the included cable fouled on the covers to my mobile phones whereas my Fiio cable does not. I also particularly liked the charging cable – it was a well manufactured cable, with gold coloured (presumably gold plated?) connectors. Given these are not intended to carry data to the unit, only power on recharging, this seemed an unnecessary but aesthetically pleasing addition.
mmmmmm golden
Practicalities
My measurements, match those on the Aune website (125x65x18). That makes the B1s sort of chunky iPhone SE sized! The biggest to say though, is that the finish on this thing is absolutely beautiful. Reminiscent of the Continental dual mono (including the light up side by side windows to the internal electronics – lit by LEDs in the B1s rather than valves in the much more expensive Continental amp) the brushed, anodised all metal exterior and (in my test unit, black) pu leather on the rear of the unit create a real high quality feel.
So what if I'm a magpie. Shiny impresses me!
The back is beautifully tactile
The satisfyingly solid switches to the sides of the B1s also add to this, and the only criticism of materials I have is that the conveniently wedge-edged circular volume control is made from a cheaper feeling plastic than anything else on the B1s. As this is the part of the B1s you touch the most, one would have thought Aune might have gone knurled aluminium or similar – but this is splitting hairs on an otherwise beautifully built piece of kit.
A focus on that average volume wheel, but did I mention it's shiny?
It feels solid in the hand, and is a real eye catcher. I had more questions about this unit in my office than just about any other piece of audio kit I have had in there… perhaps because of those shiny front LEDs and window panels.
On the top of the B1s are the 3.5mm in and out sockets and that volume control. Worth noting here, that that 3.5mm output is single ended only, and the B1s has no ability to drive headphones in a balanced configuration. To the left side from the front, the gain, voltage and power switches, to the right (from the front) the slightly weird battery charge indicator light (which gives a number of flashes to indicate charge rather than a more customary red, yellow green set up) and button, and on the base the micro usb charging port.
In my test the unit took around 5 hours to charge from a normal phone USB charger, and I was getting 6-8 hours of playback depending on what headphones (and volume) I was using. So battery life is about 1 day of normal use for me, which is fine, but if you buy a B1s you will also need to ensure you don’t stray too far from a wall socket if you will be using it more heavily.
So then, on to the first of my two main criticisms of the B1s. RF interference. It wasn’t until I took the B1s on a train trip with me, having forgotten to charge my AK70. As the DAP died, I thought the time was perfect for having a play with the B1s hooked up to my phones. Unfortunately, the results were a little disappointing. Whilst the sound quality and amplification were in line with comments further below, there was the noticeable click and buzz of mobile phone interference. I tried a few tricks to resolve, but found that turning off 4g data was the only solution. Which meant no Tidal. I suspect the majority of people who will be purchasing a B1s will be doing so to use alongside a mobile phone (see criticism 2 below) and hence I think this is a material issue for anyone who wants to stream music on the move.
And the second criticism? Volume. This is an amplifier, but it does not amplify that loudly. Whilst it does a good job of amplifying the output of a mobile phone, and pushes well beyond comfortable volumes when driving IEMs, it simply did not drive my HD600s to unlistenable levels. I cannot therefore recommend this for anybody with low sensitivity cans. This said, there is a plus here, which is sweet, sweet silence. On maximum voltage, gain and volume there was no audible hiss from any of my IEMs (including the CA Polaris, which tends to be less sympathetic than my other IEMs). So an amplifier for IEMs perhaps?
The Sound, Comparisons and Matching
As this is an amplifier, I haven’t done the standard highs-mids-lows review. Ultimately, this is an amplifier and so should just be making the existing signal louder. It undoubtedly helps some kit perform a bit better – the Shure SE425s for example, I always think sound better amplified, and the B1s drove them well, creating that wider feeling and greater clarity which the SE425s only deliver under amplification.
This said, there is a definite colouration of sound from the B1s, placing a greater emphasis on mids and low mids, and delivering a warmer sound. I have seen reviews which compare the B1s to valve amps, and compared to my Vali 2 (with the stock Schiit tubes), it sounds good – warmer than the Vali, with a greater emphasis provided on (especially male) vocals.
The net effect of all this, is that I found the B1s a little picky with headphones, especially when running from a source which has a lean to the warm anyway, like the Nano iDSD BL. With the Shure SE425s and to a lesser extent the Kef M500s, mids swamped out both the bass and the treble, resulting in a harsh almost shouting quality to music that I have not heard before. This was most evident on Yellow Ledbetter on the 425s, with guitars lost in the background and the soft vocal jarring in my ears.
Too long a chain to sensibly be mobile, but it did sound good.
In complete comparison though, the B1s sounded great with the CA Polaris, which is a little light in the low mid range. This was a dream pairing, sounding airy and clear on every track I listened to, but (from my phones and XDP-30r particularly) bringing the voices of Ed Sheeran, Bruno Mars and Frank Turner back to the front of the recording. It also sounded very good with the HD600s, where I heard a noticeable clarity and separation compared to other sources, especially my phones.
The CA Polaris and B1s played together very nicely. So well, I'm seriously considering buying a B1s just for the Polaris.
Other thoughts
The problem is, I just don’t get who buys a B1s as their first foray into mobile amplification…if you want pure amplification, the Nano BL and the XDP-30r and AK70 (esp. in balanced mode) drive louder, and there are any number of more versatile DAC/Amps in a similar price band that provide more amplification and do the DAC stuff. But don’t get me wrong – I want one. It is beautiful, it lights up and it does make a satisfying noise, especially with my CA Polaris.
Finally, one more thing I knew I would missing when sending the B1s on for the next leg of its tour. When you switch the B1s on, there is obviously some sort of reed switch circuit performing some internal sorcery. For the first second or so on turning on the B1s, it does nothing but light up – then you hear (and feel if you are holding the unit) a solid and thoroughly satisfying click as the reed switched circuit is engaged. It sounds and feels like an old valve amp clicking on. Puerile exuberance ensues. Honestly, it is beautiful, and adds to that quality feel that the B1s constantly exudes.
Conclusion
Plain and simple, I want one. It makes my CA Polaris sound even lovelier, looks great and oozes "quality product". Well matched, with the right IEMs, this is a wonderful amplifier, but the low power output and electrical interference move this from 5 stars to 4 for me.