Yoder,
Sorry, I keep using toslink and optical interchangeably but what I generally mean is optical. You can indeed run 24/192 on optical but you have to use ST (a.k.a. - AT&T) adaptors and cabling) The HiFace Evo, for example delivers 24/192 via optical. However, even if we limit the discussion to official Toslink, people have run it at 24/176.4, as long as all devices in the chain meet or exceed the manufacturing toleances for the interface chips.
The IEEE can say whatever they want, but I know people running 32-bit 384khz via usb 2.0 with no problems. There's so much bad press onusb, but it can be done right and my ears tell me it sounds quite fine -- still my favorite dac I've ever owned is usb only, and mostly because the company has so far not been able to get the spdif version sounding as good.
I don't know where you're looking, or not looking, but I have a growing collection of 24/96, 24/176.4 and 24/192 recordings and even on a 16/44.1 dac it is very easy to tell the difference.
Amarra won't upsample? Not that I use it as upsampling pretty much destroys the integrity of the music, and I'd expect just about any device that upsamples to be a compromise somewhere, somehow.
Does Amarra support integer mode yet? BTW, even if it does, it won't do so under Lion as Apple did not include a usb driver with integer support in Lion -- you have to go back to SL for that feature, and it is a great one, especially if your dac, like mine is limited to 44/16 and the higher bit rate files have to be downsampled -- different from upsampling in that it is interpolation instead of extrapolation.
Pure Music and Audirvana both support integer mode, and Decibel may now too.
Yes, the software is a big part of it -- especially anything that does away with the iTunes playback engine (Quicktime), which is most of the 3rd party apps. However, digital audio is so vastly complex and multi-faceted that it's nearly impossible to single out any one aspect as the most important. Like amplifiers, it's a combination of circuit, components, tubes, execution, and some dumb luck thrown in for good measure.
As for predicting where this business will go, I'll leave that to the psycchics -- they're probably as reliable as anybody else.
Case in point: back in the late 80s when I was a top tier IT guy at a very large company, all the industry rags were predicting the impending death of ethernet -- with the exception that it *may* still have some use in industrial automation systems. The wave of the future was Novell and IBM token ring networks. Seen any of those lately? And where did that ethernet go? Around the globe, and around and around, and around, and everywhere in between.
I thnk all of these are viable interfaces and all of them will be or some time.
And yes, there are 32-bit 384 khz digital files available, though not many, and it's absurd anyway (with the possible exception of dithered digital volume controls.) Even 24 bits is basically insane and not really fully used -- that's 144 dB dynamic range -- show me a recording that can even come close to that.
Me, I'd be very happy with a 20 bit, 250 khz dac, but no such standard exists, nor will it ever, but to me that seems to make the most sense in terms of reproducing music.
When my Metrum Octave arrives (probably another month yet) I plan o try it with both the audiophilleo AP2 -- at a maximum of 24/176.4, and directly from he mini toslink port on the mini, which will limit everything to 24/96, which means the usb converter only gives me the benefit of 24/176.4 in native mode instead of downsampling to 24/88, and until I try it, I wo't know which is better, but my suspicion is that a glass optical connection with everything above 24/96 downsampled (in integer mode) by a factor of 2 -- meaning that 24/176 will play at 24/88 and 24/192 will play at 24/96. Not a bad compromise, but to my ears the sampling frequency is much more important than the bit depth once you're beyond 16 bits (or 20 if you have the few files in that forma, whatever it was called -- now owned by microsoft and supported on only a handful of CD players.
-- Jim
