USB DACs with 24/192 via USB

Can you use FireWire instead of USB? The Focusrite Saffire has AD/DA, mixing, and a lot of different format conversions (e.g., SP/DIF I/O) for a street price of $349. As for audiophile quality, Alan Taffel, who did the series on USB digital audio in the Aug. issue of TAS, much preferred the results of the Focusrite Saffire's format conversion of FireWire-to-SP/DIF over what the Bel Canto was able to do with USB-to-SP/DIF.

And he wasn't blaming the Bel Canto; he just feels that FireWire's additional bandwidth creates a better digital stream. That may also explain why this fairly inexpensive and easily accessible gizmo does 24/192 while you strain to find a 24/192 USB DAC.

I read that series of articles too. I think it would have been better to bring
more reviewers in on that series, as all the articles about the negative aspects
of USB conversion came from one author. And as has been mentioned, if
you're going to make sweeping statements about USB DACs, bring
Wavelength into the discussion. There are some who believe a PC into a
Wavelength Cosecant trumps just about any other 16/44.1 playback.

One other thing that piqued my interest, though, was the Focusrite Saffire.
While its list price is the same as the Bel Canto, it can do many more things,
the Firewire-to-SP/DIF sounds even better than USB-to-SP/DIF, and the
Saffire's street price is $350 at any music store chain. The LE version goes for
$299.

I have a MacBook with a Firewire output, so if I decide to up the sound quality
of my iTunes on it, I'll probably go with the Saffire to extract the digital
stream from the computer. Less money, better sound. What's not to like?

I posit that the 24 bits vs. anything less is far more important to sound quality than 192 Khz vs. 96. I'll take 24/48 over 20/192 any day. 24-bit has 16 times the amplitude resolution as 20-bit. 96Khz is plenty high enough to maintain phase relationships in the treble, overtones, and soundstage.

07-29-09: Kops
upconversion is wrong way.....native is needed

I get the impression that the PS Audio DAC III is 24/192 in native mode. It upconverts lower sampling rates and shorter word lengths to 24/192. Therefore, I presume that if it receives a 24/192 digital bitstream, it will decode it in native mode as there's nothing to upsample.

BTW, the $299 Musical Fidelity V-DAC also runs internally at 24/192 and has a USB input.

07-24-09: Restock
There is something to be said for Firewire too - the best computer DAC implementation I heard to date uses Firewire (the Weiss DAC2/Minerva). But that requires extra drivers as well for 24/192 operation.

That Focusrite Saffire, in addition to having two FireWire ports and RCA SP/DIF In and Out, also has built-in A/D *and* D/A converters with a max rate of 24/192.

List price $500 (same as the Bel Canto USB-to-SP/DIF converter), but typical street price is $350. And if the DAC isn't up to snuff, one can always send the SP/DIF signal to a Benchmark, Lavry, or what have you. (PS:Lavry eschews 192K intentionally).

Bigamp
Are there any "audiophile" quality DACs that can receive a 24/192 input via USB?

It appears that the PS Audio Digital Link III has an internal native mode of 24/192KHz. It also has a USB input. As to whether it can actually receive 24/192 over the USB link, I don't know, but if it gets a 16/96 or 24/96, it's going to upconvert it to 24/196.