Hi don,
I don't mean to sound snarky, but there are lots of myths, half-truths, misinformation, and even some dysinformation concerning computer-based digital audio out there. Also, this is in no way meant to criticize bottlehead as hardly anybody outside BH has heard their dac so far. That said, a few things...
usb, when ddone right (and that does not mean async necessarily) is perfectly suitable to superb digitial playback. Secondly, there are a huge variety of asio drivers, and none of them can gurantee bit-perfect playback as there is much much too much going on inside the PC, even when carefully stripped downwith nLite) to guarantee bit-perfect playback. I also don't agree that it takes tons of money to get superb playback, but software can be a very important part. After loads and loads of experiments by myself an friends, it is clear that a windows based transport is in third place witha single-board linux box in second place and a tweaked Mac Mini, clearly ahead of everything out there atthis time.
Hi Jim,
I don't think that you have a snarky bone in your body, sir. I realize now, after re-reading my email from last night, that I could have been a bit overenthusiastic (read: inebriated) regarding friend's hardware that I have heard, and the virtues of high resolution audio files. Thank you for your patience with me, I'm new here. And thanks for the welcome, too.
Regarding USB for audio, I actually downloaded and read a fair amount of the USB Device Class Definition for Audio Devices today (yeah, I'm a bit weird). Also interesting that Release 1 of that doc was dated 18 March 1998... not nearly as old as the CD-DA standard, for sure. And you are 110% correct - USB _was_ designed with high quality audio in mind. From the Management Overview section, pp17:
An essential issue in audio is synchronization of the data streams. Indeed, the smallest artifacts are easily
detected by the human ear. Therefore, a robust synchronization scheme on isochronous transfers has been
developed and incorporated in the USB Specification. The Audio Device Class definition adheres to this
synchronization scheme to transport audio data reliably over the bus.
So what I'm reading here - at the risk of oversimplification - is that the USB standard supports high-quality audio, but very few have built software that takes advantage of this capability.
Hmmmmm. Sounds like an opportunity. In the meantime, those of us who don't have the right chops will be stuck with S/PDIF, I think. I totally welcome a USB audio implementation that sounds correct. If someone could build it at the "right" price-performance point, they'd be overwhelmed with orders.
That being said, Jim - I still think that the 16-bit / 44.1khz standard for CD-DA is flawed - but then, the Red Book was first published in 1980. I guess that my real issue (and I know that you got this) is what I said in italics near the bottom of my rambling: "...what the heck to do with these 800+ Nyquist-theorem-crippled 44.1khz/16-bit CDs?" I think that the solution looks like this:
1.) bitperfect FLAC rips of CDs (with a tool like dbpoweramp)
2.) bitperfect output from the pc to the DAC - (USB, S/PDIF... don't care - as long as it's correct)
3.) time-domain coherency in the reconstruction of the audio waveform and
4.) enough amplifier power to drive the transducer of choice
I think we got #1 and #4 nailed. Still waiting on #2 & #3.
I've been applying "gearhead techniques" to this problem here at our Casa - mainly because I'm a gearhead, and that's all that I know. I'll have to rely on folks like Doc, Paul J, Paul B, Grainger and others to come up with an elegant solution to the task of converting 1s & 0s to smooth, spacious, grain-free sine waves at a price point that I can afford. And, if it's a kit that I can actually build, it'll be awesome.
Thanks again, Jim. Great to meet you!
-Don