sclaimer: Aune provided the B1 for the purposes of this review, free of charge. It goes for just south of 250$ USD. You can find out more about it here.
Finish and Design
Talk about cleaning up: especially under single light sources, the Aune B1's bold lines border on sexy. It is a symmetrical box, ins and outs arrayed evenly either side of the half-a-flying-saucer volume pot, dual windows down the front, dual brake pads down the back. Sexy, and yet almost Sony-esque in its reliance on branding and other graffiti. It doesn't need massive FCC, recycling, and other passed-test icons. I say hide them along the B1's, ass; they take away from what otherwise, is a perfectly modern version of Vincent, from Disney's The Black Hole. The Made in China text, not to mention the website, should be much smaller, if not hidden. What really counts are the model name, the brand, and important interface labels.
Interestingly The B1 is the second China-made amp I've tested clad at least partially in 'leather'. The other one being the Oppo HA-02 . The B1 splits faux animal skin along its bum, with enough space between cheek for yet another duo of Aune and B1 trademarks. And once you've got headphones and source plugged in, and its circuits switched on, its green eyes light up. Vincent. My Fujifilm X-T1 even detected a face in the photo taken on my kitchen table. Go figure.
I should point out that the B1's metal chassis is rock solid. And while I'm no Rock, I'm no 50kg weakling either. And, twisting hard left, and wringing hard right, I've tried to bend it. There is no flex anywhere. Its volume pot is part of that: while it may look like Vincent's cap, it glides from its lowest to its highest setting with Leica ease. Sexy. And, impressive.
Just as impressive is the work that went into the B1 commercial photos (not mine). They are well shot, and comely. Good job.
And then there are the parts that show that Aune could have used a real interface designer. Symmetrical lines and stuff are not enough. Case #1: the B1's interface buttons appear to float in metal wells, but they do not. They are just improperly aligned. Not a one perfectly lines up with the case, and each cants right-wise. The B1 Manual does little to illuminate what the middle one is for. But reading between the lines, I reckon it doubles the amount of wattage to which the B1's battery has access. And then, there's the self-destruct function. Here's what the manual says (verbatim):
Never flip this button under B1 is working.
-which I translate like this: never, under any circumstances, move that easily-moved switch, or you'll blow up.
WTF? Can someone say Tree of The Knowledge of Good & Evil, for me? If there's an easy to press button somewhere and I shouldn't press it, sure as shit, I will press it. It's Murphy's Law. Aune, let's look at this seriously: if engaging the CLASS A button hurts the B1, it shouldn't be so easy to press, nor so starkly out there. Well, I took the warning as a challenge, though not necessarily on purpose. Several times, whilst prying the B1 out of my front pocket, I moved the CLASS A to the 'up' position. Whilst putting it back in, I moved it into the 'down' position. Ditto the gain gain switch. Of course the amp was on. Thankfully, the mostly innocuous power button is far enough removed from prying fingers. I've never accidentally bumped it off or on. And fortunately, the self-destruct function appears to be faulty. This is a bad design.
You may have defter fingers than me. You may never accidentally switch on the self-destruct button. But I guarantee that you will accidentally nudge the 'ear self-destruct' button, aka the gain switch, which adds about 12dB to the signal. If you've got earphones in, it may be the last time you use them.
Finally, while the battery seems to last well (I kept recharging it so I have no idea how much farther past 7 hours the 20mW setting (the lower of the two CLASS A settings). I assume that 8 to 9 hours is the most anyone would realistically get out of it. That isn't bad. It's actually sort of a recent trend. Battery life is getting worse. But Aune is biased for Class A operation, so it should tear through batteries. I'm surprised by how long its battery life lasts.
inal niggle is its countersunk in/out ports. Because they neither sit flush with the case, nor in wide-mouth wells, certain headphones/connectors may have connection problems. It's not that the jacks themselves are shallow, and their mouths just tapered out; I can plug thin-line plugs flush with the socket. It's that the case protrudes beyond the jacks themselves. Ditto USB jacks. I've not had trouble, but I foresee certain plugs not going all the way in. The B1 is designed with style in mind, but its form does not appear to follow anything but a stylistic vision. It's a shame. Its aggressively 1960s HiFi lines are incredibly handsome. Had they been followed by safe-to-handle gain and CLASS A switches, B1 would be a freaking classic.
The main reason for that is that it sounds good. It's got enough detail, and good drive power, but better than that, it has a quasi-comfy-chair sound, which you can relax into. Its treble doesn't drop off, or anything, but its stereo channels bleed into each other a little, which makes harsh headphones a lot easier to listen to. This amp is another one that really really makes the Beyerdynamic DT880/600 sound its best. And it has hella enough power to make that headphone sing.
It effortlessly drives my DT880 even at full gain/volume, with only the slightest rise in IMD distortion. At normal listening levels, it supplies wonderful power and quality signal for most, if not all home headphones. It reaches its current ceiling when driving low-resistance, semi-sensitive headphones such as Mr. Speakers Alpha Dogs whose bass, after a twist of about 50%, rattles like a can full of broken glass. Have no fear though, at normal to high volume levels, it powers them perfectly, and every other headphone I've tried, perfectly. The B1's high gain is incredibly aggressive, but not backed by heaps of current, and thus is best suited for high-resistance headphones that are never starved for current.
I am most comfortable listening to both the DT880/600 and the Mr. Speakers Alpha Dog in low gain at a setting of around 40-60% of the B1's pot.
As you can imagine, pairing sensitive earphones with the B1 is somewhat tricky. My two favorite universal earphones are the Ultrasone IQ and the Grado GR10 The first reaches borderline uncomfortable levels right as the B1 balances the difference between channels. The latter is about the same. The slightly less sensitive Grado GR8e can handle slightly more volume, but just barely. What does handle the B1's aggressive gain is Earsonics Velvet, and EM32. The thing about the EM32 is that it is a bass-and-mid earphone, which, I think, sounds best paired to sharper-sounding amps. The B1 is gracefully extended, and warm and atmospheric in the mids and bass. Its handling of distortion is beautiful.
The biggest shame is that the B1 doesn't really hiss. At all. Its background is blacker than any other amp in my arsenal. In fact, I put it ahead of the PURE II and two steps ahead of the Portaphile Micro It simply doesn't hiss. My ears tell me that it may have a bit more background noise than the Mezzo Hifi MZAK100, but only barely. And so here I am, an earphone guy, really wanting to enjoy my GR10 through it, really wanting to enjoy my Noble K10 through it, but because of its aggressive gain, I have a very hard time.
It supplies good current to low-Ω earphones, but it's not perfect. I've not measured its output, but I'd guess it's between 2 and 4 Ω. Easy-to-drive earphones: GR8, ER4s, Velvet, SM3, etc., are in tip-top condition from the get to, and suffer much less from the aggressive gain. But those expensive ones, you have that detect the hiss in the vacuum of space: those don't pair as well.
So, my petition is this: Aune, fix your gain. The B1 is a dream. A bloody dream. It is lush, powerful, and its channels bleed so sweetly. This is an amp that deserves the comfy chair, the whiskey, and a good long go at Vibrasphere, or Chicane, before hitting Wu Tang Clan. And sometimes, that comfy chair fits on the train, or bus, and props up elbows and ears stuffed with high-end earphones, not just full-size headphones. I can promise you this: nail the gain, clean up the switch problem and, BAM! the B1 will be a winner. In its current state, it is simply a wonderful sounding amp that in many ways takes the crown for doing the clean, comfy listen perfectly: but only for the big guns.
And when on the go, scale really does matter.