B1 Review, E12 comparison and
General ramblings Part 1.
Some preliminaries - Aune has been soliciting reviewers for the B1 amp. At some point (or it's already happened), Aune will announce/inform the "winners" who I guess will receive a free B1 amp for review. I am NOT one of those "winner/reviewers". I purchased a silver model of the B1 through Amazon for $189.99US plus shipping. I own it, it's mine and it now represents a sunken cost as does my Fiio E12 amp. I have no affiliation with either Fiio or Aune. So, as my grandpappy used to say - I ain't got a dog in this fight. I've read a few heavily biased comments concerning the B1, so for the sake of neutrality, let's all hope that those comments didn't come from one of the "winner/reviewers". As to the silver model, I think royal blue would have been a better choice for the color of the faux leather inserts instead of red. Nobody ask me though.
Most everyone has seen pictures of the B1, so I'll comment on the little windows. I suppose this is so you can see the discrete circuitry of the B1. Although from the Aune site, it appears that the word discrete doesn't translate. What I primarily see are two Japanese NEC 2SB772 transistors per channel. Per the datasheet, these are medium power PNP bipolar transistors. A cursory check of aliexpress shows these at 11 cents each in 100s. Aune uses the term triode in their product description of the B1. This is also in the description of the 2SB772s at aliexpress. Maybe that's where they picked up this erroneous term. It may be a three terminal device, but it's not a voltage-controlled glass-enveloped device with a heater. The general product pages at the Aune site for the B1 are a general CF. And yes, the first word is cluster. I think it does a disservice to the B1 and to Aune. Information is scattered throughout the pages, in different fonts, font sizes and over backgrounds that make some of the text almost unreadable. It's shown with a pro-series Sony portable digital recorder. I don't know - is this their target market? I think it might be better for Aune to contract their site management to someone in Hong Kong - say someone in their mid to late thirties with a proper British accent and some knowledge of western audio marketing jargon. If you're going to market your products to us brash, loud-mouthed, arrogant Americans, you best get your ducks in a row.
Specifications - they are sparse. I was particularly interested in the output impedance. It was nowhere to be found. In fact, specs in general, are a little light. One can make some inferences from this, but I won't. I did find it was spec'd at a 100mW at 300 Ohms. This showed promise. The lower power at the lower impedances wasn't too awe inspiring though. I managed to extract that the B1 uses +/- 9 volt rails from the product pages. This also showed promise as I was looking to use this amp with a pair of Sennheiser HD650s. What? That's right, 650s. Those of you who read my iBasso DX90 review know that my wife has co-opted my Fiio X5. Now after using it with my E12, she's slowly absorbing it. I found myself with a need for another portable amp. I like to sit on the deck and not have to run extension cords to plug up a desk top amp. My wife doesn't want "clutter" on her desk. The Fiio X5 is about it. The amp stack suits her fine. So, why not just another E12? That's too easy and where is the fun and adventure in that? Try something new and different when you get the opportunity. If I had any bias at all, it was hoping the B1 was at least as good as the E12 with the 650s. I wanted my E12 back. My wife is a pretty astute listener in her own right. She wasn't going to be fooled by something that she found lacking.
And what about that 20mA/40mA switch? Well, I still don't know. You can find, if you're patient, that the amp operates in Class A regardless of the switch position. It alludes to offering a higher source current for... I'm not sure. So, I emailed Aune asking 1. What is the output impedance and did it change with the gain setting and 2. Can you explain the purpose of the 20mA/40mA switch. I waited 7 business days with no reply. I re-sent the email. That was 2 weeks ago. Still, no reply. Hmm... I thought of 3 reasons for the silent treatment. 1. No one there could translate English. 2. No one there actually knew the answer to my questions. 3. They knew the answer and decided not to share that with me as I indicated that I was doing a review for Headfi. One can speculate about the current switch - are they moving the bias point along the load line because it seems like a cool thing to do? It certainly affects battery life and later, as we'll see, it did have some effect on the sound.
Since we're talking about battery life, I'll note that I got no more than 9.5 hours of use in the 20mA position. In the 40mA position, it was 5 hours and a few minutes. This was tested and timed over 18 cycles. The general battery life for the E12 is 13.5 hours. Recharge time for the B1 is 6 hours. I tested that with my Ipad charger, my Nexus 7 charger and a Belkin charger. These are 2 Amp, 10 Watt chargers. The E12 required around 3 hours for a recharge. Something to consider depending on how you plan to use your amp.
Much has been made about the heat signature of the B1. Yes, it does get warm, even warmer in the 40mA position. Hot, uncomfortable to the touch -NO. Generally warmer than the E12 - YES. My IR thermometer is out on loan. When it returns, I'll make some thermal measurements. And since Aune won't tell, I'll measure the output impedance too and report back at a later date.
Size/weight - The B1 and E12 are about the same length and width, 118.1mm X 64.8mm vs 119.3mm X 65.5mm. The thickness difference is noticeable. B1 at 17.6mm and the E12 at 14.8mm. (All measured with calipers) The B1 seems to have gotten into a stash of Big Macs and Krispy Kreme doughnuts, It's a little chunky. The B1 weighs around 8.1 oounces (230g) and the E12 at 5.6 ounces (158g).
I don't know whether a burn/break-in period is a factor with the B1 and I wasn't interested in establishing one. After a few hours of general listening to assure functionality and no gross sound issues, I pre-conditioned it for 90 hours. This consisted of nine (9) five hour periods and five (5) nine hour periods. The Fiio X3 was used as a source and the load varied between the Sony MDR-7520s and the Senn HD650s. I should note that the load had no effect on battery life. I even ran a 5 hour cycle with no drive and no load. The battery still lasted only 5 hours. In general, this is normal for Class A operation as there will be little change to collector current in idle state vs operational.
One picky issue - Aune makes a point of noting the input and output labels are laser cut. This might be fine on the black version, but it's almost indescernible on the silver model.
A few E12 comments - the E12 offers a bass boost switch. This may be attractive to some users. It also offers a switchable crossfeed circuit. It's not terribly aggressive, but it does help.
Both amps offer a gain switch. I did not use it for this review. It was unnecessary for the headphones I used.
If it seems like I've been pooping on Aune, I have - a little. Aune, like Fiio, is another small Chinese company trying to get established with some interesting and useful niche products. I wish more of this was going on in the US. Well, we do have our Schiit. They remind me of the early days of Musical Fidelity and the now-defunct (but resurrected?) Audio Alchemy. I want Aune, like Fiio, to succeed. If I seem a little rough, well, good. The company is still listening to its customers, now is the time to heap it on and push them to do things that will assist in their success.
OK, I suppose it's time I should begin waxing poetically about the sound - but wait. Soapbox Alert! What follows is an opinionated rant. You can skip to the next section for the review.
May I just say a few things about the overworked and sometimes misused term of soundstage. Oh, and imaging. Of course, this is just my opinion - my truth. If you hold my truths to be non-evident and irrelevant, that's fine. I applaud your independent thinking as long as your truths come from your own evaluations and judgment - not because you were told something is a certain way and you just accepted it as an unshakeable fact. I'll probably unleash a scatological tempest, but here it is. The first time I heard the term soundstage was around 1970/71. It was in High Fidelity magazine and related to a particular LP of a classical music concert. The concept was intriguing, but really didn't have a lot of relevance to me and my little system with the speakers placed in opposite corners of my bedroom. I saw more and more references to soundstage in the months ahead in other audio magazines. It was generally in reference to an LP - not equipment. This seems to have coincided with the advent (no pun intended) and proliferation of acoustic suspension speakers. This may, in fact, have nothing to do with that. It's just one of those correlations you make in your mind from a jumble of unrelated facts. It was much later before I read about it in the context of an equipment review. That doesn't mean it hadn't happened already - just not in the magazines I was reading at the time. There were some explanations of the concept and I felt like I was beginning to understand it more thoroughly. With my meager system and speakers and my mostly pop/rock records, it wasn't likely to be actually experienced any time soon. As I came to understand it, perceiving a soundstage when listening to music was a psycho-acoustic effect. It required that the source recording was mixed with the soundstage in mind and that your speakers were properly placed and of the type that had excellent dispersion characteristics. Sitting in the "sweet" spot was an absolute. Given that your room didn't have a lot of negative aspects to it, the stage would sonically appear between and often outside of your two stereo speakers. There would be a blend that filled the area between your speakers. This effect would attempt to recreate elements of the venue in which the performance was created. But most important was the source material. As time progressed, I saw the term often used with speaker reviews. A known recording was played and the speaker's ability to create the effect was judged. I'm not sure of when it drifted in as an equipment metric. Imaging was described as a delineation of orchestral groups such as the string section or woodwinds within this stage. It was seldom applied to a single instrument. It was rarely, if ever, used with pop/rock recordings. Electric instruments were normally recorded in the studio as a line input to the console. Drums or any other non-electric instrument was mic'd. Those were the exception, not the rule. Any sense of stage was formed only in the mix engineer's mind as a real one didn't exist. Even live concerts were handled much the same. The point source would have been the amp stack anyway - not the instrument. I don't think many recordings were made with a microphone set in front of an amplifier. Imaging was often seen as an earlier indication of resolution. The ability to not muddy-up the mix. One aspect of the soundstage effect was that it involved both ears hearing the output of both speakers. The left ear would hear a predominance of the left speaker along with L+R and a L-R phase and timing oriented component. The same for the right ear. Anyway, that's my understanding and now to muck it up a bit. I believe it was a Len Feldman article/column (Popular Electronics maybe) on tape recording. Len warned that using the headphone monitor on your deck would not give an accurate picture of the soundstage. With headphones, you had a clump of sound on the left, a clump of sound on the right and a clump of sound somewhere in your head and never the three will meet. It was impossible to hear a proper soundstage with headphones. That wasn't too big a deal then - I rarely listened with headphones. Fast-forward to the mid-1990s and headphone listening was becoming somewhat popular. I became interested as it was an excellent way to discover nuances in the music that you might miss because of room-effect aberrations. I've never had an ideal room, so compromises have always been a part of my listening to music. I have had numerous opportunities to hear outstanding systems in excellent rooms over the years and the effect of a proper soundstage can be mesmerizing. I've yet to ever hear any thing close to it through headphones. Attempts were made in the 90s and early 2000s to address this shortcoming with headphones. Several amps had variations of a passive crossfeed circuit and there were some outboard active spatial processors. These helped but it seems now, this whole idea has been left on the trashpile of audio history. So, basically, if you haven't experienced a proper soundstage recreated from a recording utilizing a system with speakers, you haven't heard a proper soundstage. This is not to say one doesn't experience a sense of "spread" using headphones, but an actual soundstage, no. So, yeah it does bug me a little when someone is recounting the soundstaging of various headphones in the most adamant way with sprinkles of imaging references. I don't know if the reason for this is to try to convey some sense of reviewing prowess or knowledge, but it just comes across as a little sad to me.
And since I'm on the topic of reviewers, something else that bugs me are the omissions I find in most online reviews. I read the prolific descriptions of what the reviewer heard, often excruciating levels of detail and minutae. I think to myself sometimes what a sensitive and discerning ear they must have. They could probably hear two fleas in a pillow fight and go so far as to note one of the pillow cases was made of Egyptian cotton and even declare the thread count. What's missing is any list of the source material they listened to or even a hint as to what they used to hear all these obvious differences. Also missing is any mention of their associated equipment. What was used in conjunction with the device under review. From some of these reviews, I can only surmise it must be some megabuck equipment involved. Resolution out the doopty and noise floors approaching 150db. But who knows, nothing is ever listed. I have, on occasion, attempted to ask these questions of some of the reviewers. It's often met with a defensive or combative response. What's worse is that his buddies on the forum jump in and start piling on. I know that I can come across as a cynical fargin' icehole sometimes (I'm still working on that). But I've had my wife screen my query before I posted it to make sure it did not sound in any way as a challenge or hostile - just a simple question. I started asking via PMs instead to avoid any public incursions. Sometimes I would get an answer or again a combative response or no response. Some of the reviews have had at least a song list. Looking over it, I realize I've heard of no one there or the songs, but that's OK. There's lot of music/artists I haven't heard of. So I do a search on these songs. Most show up as a YouTube video or as a low data rate MP3 download from a bands website. I'll PM the reviewer to see if that was his source for the music also. In most all cases it is. That at least allows me to place the review in some relateable context. Often when I receive a reply concerning associated equipment it goes something like "I'm streaming from Pandora through my Macbook Pro and listening directly using the computer's soundcard". That's fine, we all started somewhere. And if he believes he heard all that stuff in his review of those headphones, that's just fine too. Now I know how to treat the review as it pertains to my interests. I may think he's bonkers, but if he shares those details, there may 20,000 other folks out there who have the same setup. If they choose to believe he actually heard those things, it's something they can identify with despite what I or anyone else may think. I just want a chance to assign my level of relevance to a review by knowing the full story. I still cling to the antiquated notion that if you're going to claim you hear certain things in a review, the source (LP, CD, file) should be of sufficient pedigree and content as to provide those elements. The intermediary equipment used should be of sufficient quality and resolution to allow the elements of the source recording to be transferred to the device under review. It seems I'm becoming a minority in this regard because these reviews are posted with no source material list and no mention of the other equipment used. Beware if you decide to ask. Maybe we should demand a picture of the reviewers equipment - making a list of expensive equipment is easy. I've posted pictures of some of my gear in the DX90 review and have no reservation about doing so with this one.
Review continues-
OK, enough already. How does it sound, Doc? Is it head and shoulders above the E12? In a word - No. Don't tell me they sound the same. They don't and I'll cover that in some detail.
Well, that's part 1. I'll finish compiling my listening notes tonight and if I can still log in, I'll post part 2 tomorrow. Please, no hate mail, yet.