To B or not to B, is the question... corny jokes aside, most portable amp manufacturers don't mention what class their amp operates in. Simply because each of the different modes have their own benefits and drawbacks. How ever, the exception to this rule is with Class A!
What sets a Class A amp apart is it's always on or always conducting operating mode. Which lends itself to a faster response times in theory because the components are always ready. Now you may be wondering, if Class A is indeed the best why doesn't every one use it for everything? Well two things, it's very inefficient, being always on means a lower battery life is expected and there will be heat, how ever when implemented correctly as executed by Aune I found neither of these "draw backs" to be troublesome!
Priced at $229 the Aune B1S certainly proves it self an amazing value! In stock as of this writing from both Amazon and Penon Audio.
Build Quality
Aune's B1S is beautifully constructed, with a brushed metal chassis encasing a beautiful clear panel with either a red or black textured back. I found no visible gaps in the chassis, nor any chips, cracks or even scratches. The entire design is seamless, beautiful and inspires confidence!
The 3.5mm and micro usb jacks are solid, with no play,wiggle or action on them! Firm, solid connections every time.
The volume knob is smooth and precise, I had no problems with volume jumps or channel imbalances. Additionally the side sliders have a good solid action.
Function
The B1S offers both a voltage gain slider and a current slider, allowing it to operate in both 20mA and 40 mA current modes. For the purposes of my review I keep current at the 40mA output and adjusted the gain as necessary.
Functionally, the B1S had plenty of space on it's front side for everything. There was no crowding even with thicker 3.5mm inter-connectors, I was easily able to adjust the volume even with the largest of my 3.5mm cables. Plus that fact that everything was front mounted made it pocket friendly. It drove everything from my HD 800 to my Hifiman HE 4XX with ease and authority, but it will not however drive larger or less efficient planars such as the Audeze LCD 2 my HE 4 or less efficient dynamics like my AKG K240 or my ZMF Eikon. Aune did not create this product to be a power house, but rather carefully crafted it to deliver a phenomenal quality of sound for use with more efficient headphones and iems.
Sound
Just how phenomenal is the question no doubt. Typically I associate a sort of thickness or warmth with Class A amplifiers. The B1S how ever did not meet my exceptions, rather I found it to have much more clarity and edge than I was expecting! If fact what little warmth it brought was almost always non invasive.
The B1S characterizes it self with a natural presentation steeped in an inky blackness paired with impressive resolve. Transient information really stood out while using this amp, though there was a slight lack of macro dynamics or aggression. Micro dynamics or small changes in volume were vary apparent, how ever larger more sudden shifts lacked a little. Frankly though with so many headphones and DACs offering a more aggressive sound I found this minor drawback to be mostly harmless.
To help gain some insight on how the amp performed I pair'd or compared it with each device pictured and used my Modified ATH ES-10 as a reference point. I also took the time to compare how the single ended performance of the B1S compared to the balanced output of my Shanling M3S and Geek Out v2+
Shanling M2S Line Out into B1S vs M3S SE and Balanced Out
Overall I found the M2S to be a poor partner for the Aune B1S, as both have a more natural sound. The music as a whole lacked excitement. The M2S and B1S are voiced similarly and as such didn't really impress me. How ever you guys may likely remember that the Line Out of the M2S didn't really scale all that well, all in all I think single headphones owners of the M2S would be better off upgrading to the M3S and utilizing it's balanced out put.
Specifically speaking, the M2S and B1S combo had a wider image over the single output of the 3.5mm Single End output of the M3S. While the M3S offered a better sense of both height and depth, resolve and transients response was similar between the two. The single ended M3S had a slightly more energetic envelope, with a slight de-emphasis on the decay and release of notes. On the other hand, the M2S and B1S had a touch of emphasis on the decay and release of notes.
When using the balanced output of the M3S, the B1S and Shanling M2S only had their uniquely magical romantic mid-range as an advantage. An while I LOVE the M2S, I do feel it brings the most value when it's alone.
Now, I would imagine the Cayin N3 would make a good partner for the Aune B1S. It had a distinctly exciting almost dry sound and it's line out scaled better.
Shanling M3S Line Out to Aune B1S vs Geek Out V2+
Wow, this combo tough to part ways with. Priced at about $500 for both THIS combo is in my opinion the golden middle ground in portables. And what's best about it is that it's NOT balanced! Going balanced can cost anywhere from $60-120 per cable per headphone. The price varies depending on what headphone that you have, so for those of you who own a single primary headphone that you use both at home and while traveling will likely find going the balanced route worthwhile. How ever, if you have more than one primary headphone then the balanced option because less cost effective and can be almost cumbersome.
That said, let's break down how it compared again'st both the SE and Balanced output of the Geek Out v2+ as well as how the M3S own Balanced Output compares to the Line Out combo with the Aune B1S.
Lows;
M3S Balanced vs M3S LO Aune B1S; Comparatively the M3S balanced output was consistently drier and sometimes tighter. This was most noticeable with synth bass lines, with EDM and some Hip-Hop I found a little bit of emphasis and smearing in the low end with the B1S. Though for most bigger stringed instruments and drums especially the B1S had the advantage. It's slight touch of decay made for a more natural envelope overall in comparison to the artificially faster M3S.
M3S LO Aune B1S vs Geek Out SE/Balanced; Sadly, for the Geek Out v2+ it's SE output sat in the middle of this pack. It did nothing wrong but it wasn't as clear as it's balanced output and wasn't as engaging as the Aune B1S.
For the most part balanced out of the Geek Out v2+ proved to be the more technically correct presentation, with a better sense of power and overall resolve. On the flip side the Aune B1S again had a more natural envelope. This most obvious with natural skinned drums, the Geek Out V2+ was sometimes too percussive lacking some of the body or resonance of the instrument itself, just a lot of attack with too little decay. With the Aune B1S there was enough attack and never too much decay, an every single time it's envelope was just more natural. Though, the Geek Out V2+ did better with some headphones than it did others.
Mids;
M3S Balanced/Geek Out V2+ [SE & Balanced] vs M3S LO Aune B1S; Tactility and edge stand out the most with the M3S/GeekOut v2+, never too hard though always distinct. How ever, there was just something magical about the B1S, with a well balanced headphone in every instance.
In the event that you happen to have an already soft romantic headphone and you'd like a bit more edge and aggression, than the Geek Out v2+ or M3S Balanced out will suite your needs best. However, if you don't mind a gentle'r more polite tactility, you'll find that even warm headphones like the HE 4XX pair nice with the Aune B1S!
Specifically, with the HE 4XX I found horns and vocals to have an added creaminess to them. Never lacking any airiness or breathy notes. Even heavily distorted metal guitar riffs had plenty of bite and were beautifully offset by gorgeous creamy solos! Though, while never overly saturated, the Aune B1S was still has a rather wet mid-range presentation.
Highs;
M3S Balanced vs M3S LO Aune B1S; Native balanced out from the M3S proved to be a little too sparkly some times, while this helped draw attention to ambient noise present in the track it also detracted a little from some mid-range textures. Though the balanced output of the M3S had a nice sense of excitement!
The Aune B1S wasn't as hard but was at times a bit under-defined. In some cases I found snare drums and other snappy percussive instruments to be a bit taken back compared to the M3S. Though there was a nice added sweetness to metal bells.
M3S LO Aune B1S vs Geek Out v2+; The Geek Out V2+ has an amazing sense of excitement and presence up top with no lack of detail or resolve. In most cases, it's drier presentation helped define vibrato more readily in bells and more clearly defined string/fret noise in guitars and other hand operated instruments. Unique though to the Geek Out V2+ as well was it's sense of space, while having it's own top end emphasis it did not take away from the mid range any.
The B1S presented it self more smoothly in every instance and often lacked resolve and clarity when compared to the Geek Out V2+.
Imaging;
M3S Balanced Out vs M3S Line Out Aune B1S; Imaging and precision were very impressive on the Aune B1S. In comparison, the M3S while equally wide, was often not as deep nor as precise. It's often more emphasized top end sometimes detracted away from the sense of spaciousness.
M3S Line Out Aune B1S vs Geek Out V2+; Once again the B1S impresses, for the most part the two were on par. In some cases with a more intimate master, the Geek Out V2+ balanced was airier, but otherwise both were excellent.
Resolve;
M3S Balanced Out vs M3S Line Out Aune B1S; The M3S had more resolve on both ends of the spectrum but was overall just behind the Aune B1S in the mid-range resolve. It's top end emphasis brings out more ambient noise, breathing, spoken words in the back ground, foot steps, the occasional air conditioner compressor starting up and things like these. How ever this added attention to ambient noise does sometimes take away from detail in the mid range.
The Aune B1S on the other hand often missed out on some of this ambient noise in exchange for providing a clearer picture in the mid range. The slight variation in tone of strings as they come to a rest, a change in a singers voice just after they take a breath a little bend at the end of a Guitarists solo. Details like these were more apparent with the B1S. Not to say the M3s native balanced out lacked any of this, but these details were not as vivid from the M3S as on the Aune B1S
M3S Line Out Aune B1S vs Geek Out V2+; The Aune B1S for the most part did not match up to the Geek Out v2+ sense of resolve especially with darker headphones, the only time it did was with brighter detail oriented headphones such as the HD 800.
Overall;
What I found was overall, the Aune B1S paired with the Line out of the M3S did the most right with the widest range of equipment. While the M3S was very impressive it only really shined with darker or more relaxed headphones and requires use of the balanced output. An the Geek Out V2+ can be very polarizing, with some headphones I love it, with others I absolutely hate it. Again, the combined line out of the Shanling M3S,and Aune B1S check all of my boxes and provide what was the most enjoyable presentation and timbre overall. It was by no means the most technical listen, but rather put emphasis on the details that I enjoy the most while keeping a perfectly natural timbre. An better yet it allowed me to finally enjoy my HD 800 on the go!
In keeping things balanced, as impressed I was with the Geek Out V2+'s balanced performance, it's lavish praise ends when the Aune B1s is sourced with an even more resolving Digital Audio Player.
With what I felt was a top of the line source, the B1s personality shown the brightest. It brings a touch of warmth and smoothness to what ever you pair it with. In the mid-range DAP market you'll find clearer, brighter more energetic ESS Sabre implementations will pair wonderfully with it. How ever with the HM 901 which is itself quite linear, in that it has neither emphasis nor de-emphasis, the Aune B1S was hit or miss. While this system was consistently better than the Geek Out V2+, it was equally as polarizing.
With the 901 as source, the B1S maintained every bit of clarity and precision the 901 offers, I did use the hm 901's HD filter however as opposed to the Vintage filter that I personally prefer it with. The problem however, arouse with the timbre. At times there was too much sweetness in the mid range and a lack of resolve in the lows and clarity up top. Not to say that the Aune B1S is a warm amp, but it does add a bit of decay, and body into the mid range. That said, it will work best with brighter headphones if your planning to pair it with a top of the line Digital Audio player.
The most relevant comparison if of course to my Head-Amp Pico Power. With the HM 901 I prefer the vintage filter as this helps to de-emphasis the top end glare that's inherit to some ESS Sabre Dacs by using a high pass slow roll-off filter. The Pico Power reflects this nicely, adding virtually nothing to the tonal presentation and only improving the existing clarity and resolve. The Aune B1S on the other hand sounded best with the HD filter which maintains a linear top end response from the DAC.
I will also mention that I can NOT stand my HD 800 with this system... regardless of the filter or the amp. As I just find it to be too boring... very non engaging.
Still let's break down how the two amps compared with my modded Audio Technica ES 10.
Lows;
HM 901 Line Out Aune B1S vs HeadAmp Pico Power; Wood winded stringed instruments were often a bit too thick with the Aune B1S, while there was a nice amount of fret noise there was often too much decay.
Bass guitars and larger drums found a slight lack of power as well with the Aune B1S. There was a marginally diffuse nature to their presentation, with the Pico Power presenting a more defined leading edge or attack.
Switching to the HeadAmp Pico Power resulted in a nuanced more clearly resolved and articulate presentation. The envelope with the Pico Power was cleaner, a more defined decay that transitions into a very clear release. The vibrato or slight variation in tone of some of the larger stringed instruments was a bit smeared with the B1S. Again, swapping to the Pico Power I was able to more clearly follow the slight changes in pitch as the notes slowly faded beneath our threshold of hearing.
Mids;
HM 901 Line Out Aune B1S vs HeadAmp Pico Power; Each of these amps had it's own strengths and weakness in relation to the mid range. With busier sections of music the HeadAmp Pico Power maintains it's clarity and purity. With Classical duets, such as those featuring only two instruments, it can at times demonstrate some dryness. Though this is likely a result of the HM901 and less of the amp it self.
How ever, the Aune B1s having just a touch of sweetness does better with these classical Duets. Though with busier sections of music it does not retain as much of the HM901's clarity and can smear the sound ever so slightly.
Highs;
HM 901 Line Out Aune B1S vs HeadAmp Pico Power; Again the HeadAmp Pico Power takes the cake, keeping more true to the source and presenting more resolve. If though you want to add a little sweetness up top than the B1S is the way to go!
Imaging;
HM 901 Line Out Aune B1S vs HeadAmp Pico Power; This one was tough, in most cases the HeadAmp Pico Power proved to be a bit deeper and more spacious, how ever the Aune B1S was consistently a bit wider. Not that it lacked space but it wasn't always as airy, though the added width does create the perception of airiness especially with headphones that are themselves very spacious. Though with more intimate headphones, the slight decrease in air and spaciousness is noticeable.
Resolve;
HM 901 Line Out Aune B1S vs HeadAmp Pico Power; Again, the HeadAmp Pico Power proved to be more resolving, having no emphasis nor any de-emphasis. While the Aune B1S wasn't far behind, it did in some cases simplify some transients as a result of it's slightly emphasized decay.
Overall;
All in all I think the Aune B1S plays best in the market it's priced around. While it does scale nicely, when compared to what I feel is product designed especially for a top of the line portable digital audio player, it doesn't prove as competitive. How ever, tonally speaking if your looking for something that adds a bit of sweetness than the B1S is perfect for you!
Of the various portable systems I own, to date none of them has been good enough for my HD 800. Most are either too technical and just joyless to listen to, or a lot of fun but technically lacking. The idea of owning a flag ship headphone is to have the very best! Thus when I'm listening I have no desire to lug around this massive headphone to listen to a either a fun system or a technical one. Even my own HeadAmp Pico Power proves to often be a poor amp for the HD 800... as it's inherit flaws are by no means masked by the almost invisible Pico Power, making for a very technical but mostly lifeless listen.
That said, the Aune B1S and Shanling M3S proved to be the FIRST portable system that combined both pleasure and technicality into the HD 800. An while most of you will not by stepping outside with your HD 800s, some of you may want to enjoy them away from your desk/office/bedroom or where ever you have your main system!
That said, while the pairing was not the most resolving, not the most spacious, didn't have the tightest bass, nor the most extended top end. It was with my HD 800 simply pleasurable to listen to! With the Aune B1S and M3S I truly had the best of both worlds!
The B1S added just a touch of meat to the low end that the HD 800 needed, additionally it presented a phenomenal sense of resolve pair'd with a pure creamy mid range. An the top end had exceptionally clarity with just a touch of sweetness. So thus those of you who own headphones with a neutral tuning will find that for portable use the Aune B1S is really top notch, especially with some of the very dry portable products it's priced around.
An when I pair'd the HM901 with the B1S I found the bass to be too intrusive, the HM 901 it self has a some what powerful sound signature. Thus when pair'd with an amp that is anything less than invisible, it often winds up having too much of something. In this case the combo just had too much emphasis in the lows for my tastes and enough enough texture and clarity. While this was nice on some tracks with the HD 800, it was not on others.
In conclusion and all things considered the B1S proves it self an incredibly pleasurable portable amplifier. Going back to the HD 800 Shanling M3S and Aune B1S combo, that was a $500 system that I found drove a $1000 headphone beautifully! An it did so better than portable systems that cost in some cases three times as much! An while there is always better, what the Aune B1S delivers is value and balance. In the land of diminishing returns the B1S is with out a doubt designed and priced in such a way that makes it by far one of the best bang for your buck purchases as it does so much right. Chasing after upgrades is often met more by differences than true end over end improvements and really requires an almost super specified system in the end.
For example, I have two portable amps in my collection. My HeadAmp Pico power and my iBasso PB2. My Pico Power is single ended and has a specially selected Li-Ion batteries to help it sustain more current for power hungry but efficient Planar Magnetic Headphones and easier to drive dynamics. My iBasso PB2 on the other hand has an entirely separate battery pack, upgraded Op Amps and current buffers, it specifically drives balanced headphones that require a lot of power. Such as my Hifiman HE 4 or my AKG K240. Each of these amps ran me around $500 after all upgrades and modifications, and both were the result of quite a bit of trial an error. The iBasso PB2 is also now discontinued... so while better does exist, it doesn't come easy in portable systems.
Hence, going back to the Aune B1S it's got an amazingly black back ground, a wide sound stage and unique magical mid range! It's euphoric sweetness is unmistakable and really adds something special to any system that finds it self uninviting! It's uniquely sweet tonal balance gives it enough flexibility to help patch up imperfections in both your source or headphones, while also bringing out the best both! An what more can you ask from an amp, that to simply add enjoyment and pleasure into your listening experience!
