loud enough? That hardly seems to be an issue...I am currently using my formula s/powerman 6 watts at 16ohms with my chord dave/blu2 and have no problem with volume on my susvaras and the bakoon is twice the power of the formula s and everything I have read speaks of people loving the susvara out of the Bakoon
As I understand it (and I have no real understanding of electronics, so please correct anything I say!): power is related to slam/grunt//headroom (measured in watts); gain is related to volume, stated as dBs. Gain is a measure of usable amplification, essentially the ratio of maximum output voltage for a given input voltage at a specified THD. (THD of 0.5% is not just a measurement, it can be heard. That's why I was asking for 0.1%, which I think most audiophiles would agree is negligible. Quite possibly the gain will be almost as much at 0.1% as 0.5%, but still it would be good to know.) Anyway, how much gain the amp provides tells you how loud you can play it before it distorts. (In general, amps sound better if you don't have to push the power supply to near its rated max.)
SNR is measuring something else, a different kind of distortion - how much volume range can you get out of the amp, from its maximum gain to where the signal disappears into the inherent background, operational noise of the amp. This noise is not the same as THD, which is related to the accuracy of the amp in reproducing musical signals.
That's why the spec that Koven got from Bakoon doesn't help much. 96 dB S/N is very good, certainly, but if you want to know how loud it will play into a particular load (60 ohms in this case), power ratings alone won't tell you that, nor will SNR. And as it turns out the SNR was measured at 5 watts into 8 ohms, which is 2 watts more than the amp will provide at 60 ohms, so it can't be very meaningful.
I did email Bakoon asking for gain figures and got this response from So In Chae:
Thank you for your email and interest in our AMP-13R. I followed up the head-fi thread and indeed our AMP-13R is getting discussed there quite a bit. It’s rather unfortunate that I do not own the Susvara, as I know that there are many happy customers and professionals around the world. I certainly hope we can manage to get one pair soon.
As for your questions, we have limited answers available for now, as our R&D center in Japan is closed due to pandemic, and we don’t have direct access with all the measuring equipment there. For now, I can answer that the SNR of 96 dB was measured at 5 watts at 8 ohms. Though we have not tested the AMP-13R at higher impedances, like the Susvara’s 60 ohms, we can expect better “numbers” due to easier load, but will have to confirm later when we get back to our R&D (hopefully soon!)
I want to add one more thing that we have opted not to disclose some of these data, as sometimes it leads to misjudge our products without actual listening. This goes the same for those parts makers, chipsets, etc. Simply put, lowering THD as much as possible was not our main design goal. Quite possibly the most important one was the bias stability, which also lead to greater benefits of removing source resistors, which can be considered a form of feedback. So the AMP-13R is now completely free of feedbacks - and even though this new bias circuit increased THD, it lowered output impedance to about a quarter compared to previous circuit. This was our best design choice, and it delivered much better listening improvements and I believe many are now very fond of.
Low output impedance is a good thing, however I don't understand how a 60 ohm load is easier and will give better "numbers" than a 32 ohm load (which quite a lot of headphones I think are designed to). The higher the resistance the more work the amp has to do, the lower the power it can provide.
), familiarity with any audio product but stretched in time is important. Someone in here already wrote something about how his view of that Bakoon changed, I think it was @koven.
Sure 0.5% can be heard, if you're listening to test tones in an anechoic chamber. Otherwise in more practical applications, THD is more or less irrelevant unless it is extremely high or low, e.g. at <0.001% you can probably have full assurance of zero distortion and vice versa at I don't know, let's generously assume >1%. Anything in between is essentially a gray area on negative audibility, masked by your music, even your room. 0.5% THD translates to -46dB attenuation [20*Log(0.5/100)], if you assume the average listening volume as 80dB, that is a 34dB SPL distortion peak i.e. not constant, so maybe millisecond occurrences. Take your SPL meter, or download one on your phone, and check the ambient noise level in your 'quiet' listening room, I bet it's +/- 30dB, probably closer to 40dB if you have a computer, air purifier, open window, or whatnot. Compound that with the fact that you're listening to music, not test tones, and personally I wouldn't put money on being able to distinguish 0.05% vs 0.1% THD reliably. Yes technically THD, IMD even more so, is an objective reflection of accurate reproduction, but pragmatically it says little about the subjective perception of sound quality. In fact many consider added low or 2nd order harmonic distortion as euphonic and desirable, which is somewhat inherent to many tube topology.
