Delightful DAC Week :~)

[Jud]

Doesn't support DSD or anything above 192 kHz either. So far just been listening through the USB input.

 

This DAC really proves the numbers don't mean a thing in and of themselves.

 

First of all, woot! Fun times!

 

Second the numbers mean plenty; just have to try to understand which numbers mean what. Lots of misinterpretation by well meaning folks who want to oversimplify the world (aided by marketing that is only too glad to tell you if you've just got the Wizz-Bang 101 process happening inside your DAC, it's the *best* *sound* *evah*!!).

[Jud]

Chris, if you can grasp it, please explain to us what is Closed-form digital filter... I have read the schiit but...sounds like a foreign language...thanks.

 

What "closed form" means in mathematics is a problem that can be solved in a reasonable number of steps using "well known" mathematical functions. Without computers, it implies there is an exact solution rather than one that must be in some sense estimated (e.g., approaching a limit, as in calculus). When there is a computer or similar resource involved (such as apparently the Yggy chips), the notion of "well known" expands a little because there are "numerical" (non-exact, but very quickly done by computer) functions that can be included.

 

Therefore Schiit's claim could be read to mean that instead of the normal tradeoff between aliasing, ringing and phase distortions all DAC filters have had to negotiate, their filter resolves the input exactly. That would be quite a strong claim, as you can imagine. Whether that is really what they are claiming (and what the Yggy does), I don't know. But it at least appears to be implied by their statements.

[Jud]

Very very few recordings are true 24 bit .

 

There's no system capable of rendering a 24 bit dynamic range. 20-21 bits gets down into the thermal noise of the electronics.

[Jud]

I struggle with buying anything I cannot pronounce!

 

How hard would it be for you to say "Lamborghini"?

[Jud]

Just to let all know, that I am Co-Founder of Schiit Audio, the designer of all Schiit Digital products and therefore quite partisan.

 

Designer of the first (Theta) and second (Schiit) DACs I owned and thus responsible for 25 years or more of my listening pleasure - thanks.

 

I am not sure it's possible to answer all my questions about the filter, just due to the level of my curiosity. If it gets tiresome, I'm sure you'll have no problem not answering.

 

The problem other filters have with frequency and time domain being conjugate variables, so as one is optimized the other is "pessimized" - this isn't a universal problem brought on by real world conditions not meeting the Sampling Theorem's requirements, and doesn't apply to your filter? So it doesn't ring, neither does it alias? Or it does?

[Jud]

JoeWhip, we've been leading the same life. Also a customer of Jack's, chatted with Mike by phone in the early days, started with the Pro Basic and upgraded it, went to Bifrost....

[Jud]

Hmm. You'd think this would actually be easier to do mathematically -- that is, keep the original samples and just interpolate between them for the extra samples. So it is puzzling why "everybody" doesn't just do it that way. But I am undoubtedly vastly underestimating the difficulty of doing so...

 

The other thing to address is that the Yggy, being a true ladder DAC, is advertised as only being able to express at most 21 bits of depth. I know the traditional defense for that is "you can't hear the lost bits anyways above the noise floor", but that is kind of a lame defense IMHO; it's exactly the argument that opponents of HiRes audio throw at it in the first place. I wonder if the best PDM DACs are equally unable to express the equivalent of that bit depth. If not, then the deficiency is shared, but if so, then that could be a point against the Yggy.

 

Regarding "mathematically easier" - intuitions based on simple arithmetic do not translate well to a world of Fourier transforms, matrices and such.

 

Regarding bit depth - no, it's really not a problem. It's explained in an FAQ at the Schiit website, and has been discussed here in other threads.

[Jud]

So for decades nobody else has thought of publishing or even implementing a sample-preserving/phase-shift-minimizing upsampling algorithm for PCM? Again, seems hard to believe. Is there nobody out there with the necessary knowledge willing to examine these claims critically?

 

Folks have, which is why I'm curious to find out more about the Schiit filter. Miska I believe has mentioned he has done filters that keep the original samples, but likes them less well than others he provides with his software.

 

The other thing I see people say Oh Wow about regarding the filter is the 15,000 taps. First, this is actually not necessarily a high number. iZotope SRC bundled with A+ can be adjusted to use a couple million taps if desired. Second, higher is not necessarily better. Taps can be thought of as the number of times the filter touches or adjusts the signal, and therefore more taps = steeper cut = more ringing, ordinarily.

 

What I'd love to know is whether this filter is claimed to solve the conjugate variable problem.

[Jud]

Mike, I'm glad you didn't resist. What you wrote is exactly what I was looking for. It all looks really good, and I look forward to hearing you and meeting Yggy at RMAF.

[Jud]

Audio equipment changes hands all the time for various reasons. Compatability, tastes, finances, WAF, etc.

 

It shouldn't be interpreted as meaning there's an issue with the product.

 

Especially when it's a grand total of what, 3 or 4, out of hundreds?

[Jud]

CMedia is not only only maker of USB interfaces for DACs. There are Amanero, XMOS, etc. If Schiit really wanted to, they could have upgraded the dated USB Gen 2 board in Gungnir... but that would really shrink the difference between Gumby and Yggy.

 

Yeah, there's got to be a nefarious explanation. It couldn't possibly be that the supplier that makes the part they've specified for their design, and with whom they have a contract, has limited supply.

[Jud]

Back in the early 1970s, before I founded Theta Electronics, the tube audio products company, I had a busy part time biz rebuilding Dynaco Tube Amplifiers. At that time I had converted to the tube based practice for my own system, convinced that tubes sounded better than the solid state gear of that era. In my ramblings, I met John Koval, a man who had designed a modification for the old Qual ESL loudspeakers which made them sound much better. “The mod gets rid of a 5 db bump in the 200-400 Hz region which makes them much flatter” he explained. I told him that I was enchanted with the sound of tube amplifiers and preamplifiers. He explained that as long as the frequency response was the same and the levels were precisely matched, there was no way anyone could tell any amps/preamps apart in blind A/B tests. He had built a custom box that matched levels and randomized any two amplifiers or preamplifiers with a pushbutton to switch between them. Bullschiit, I thought, what about the solid state A/B box and its sonic signature.

 

 

Intrigued, I built a similar box with passive relays and a passive attenuator. Damn, if he wasn't right. It is really difficult to tell differences in an instantaneous blind A/B test between tube gear that I built versus some commercial gear that I was not particularly fond of. I used to bet John beers that I could tell the difference. Usually, I won at 7 out of 10 picks or so – the best I ever did was 9 out of ten. But it was really hard.

 

 

This whole deal made me wonder if I was crazy hearing differences between amps. If what John said was true, and many others have said in the passing 40 years or so, there is no point for an audio hobby involving anything other than transducers. WTF?

 

 

So I tried something new – I still did the blind A/B tests passively, matched levels, but allowed long-term listening to each; at least an hour or two with known recordings. Guess what! Suddenly I knew which was what. I tried it out on John B and Mike and Dave and all my other audio buddies. They called it too – tubes vs a bad solid state preamp. Every friggin' time. My enthusiasm had returned. This taught me that the human ear is an integral, NOT differential device. The audio science police traditionalists no longer dampened my enthusiasm.

 

 

 

So much for the blind A/B instantaneous naysayers. All that matters is frequency response, they say. People can't hear anything much above 20KHz in their prime, less later. The ear has a short memory, it is all bias, blah, blah. They should take up a different hobby, say stamp collecting.

 

 

Thanks to Dr. Heil, the inventor of the Heil AMT speaker who shared this experiment with me over 40 years ago, Consider this: I am 67 years old – my high end extends to just under 15KHz (not bad for and old fart). I can play two pulses 200 microseconds in length separated by 20 microseconds and clearly hear two pulses. Not unusual until one considers that 20 microseconds corresponds to a square wave of 50KHz. And then, there is the time domain – home of spatial cues which audio science measurement traditionalists ignore. I believe that in the quest for the best sound, an open mind is the most important asset. I will even listen to cables, even though I believe in my heart that all technology about cables is well known. Who knows, even an old fart like me could be surprised.

 

 

 

Until then, yet another retelling of my old John Koval saga is 40 year old news to me.

 

I did a dual blind test here, in a thread I keep promising to resurrect and write a conclusion to. The test was two different acoustic guitars playing at the same time; here are pictures of the guitars, guess which one is in which channel. Self-declared objectivists got a two-second sample followed by one second of silence, repeated 10 times (total of 30 seconds); self-declared subjectivists got an uninterrupted 30-second sample from the same portion of the same track. So no audio memory, just what's best at telling the difference between two acoustic instruments heard simultaneously - brief snippets, as is thought best for A/B/X testing; or a longer listen, which objectivists will tell you (correctly!) is problematic when (at least one kind of) audio memory is involved. (I note "at least one kind of," because if I heard even a bad recording of the voice of my father, who passed away 5 1/2 years ago, I'd recognize it in a microsecond.)

[Jud]

Bow down to the Norse Gods . I have drunk from the Tree of Life , The Mighty Yggdrasil and have eaten its Schiit .

 

It taste good !

 

Hey, I'm supposing I'll like Yggy too, but - eeww, gross.