USB -> SPDIF 24/96+ units

[padam]

Berkeley Audio Design has come up with one as well, also uses StreamLength (really pricey though)

[grawk]

The apogee duet 2 is a USB 192/24 converter. Mac only, tho.

[Shahrose]

I've owned the several soundcards (to use as transports including the Essence ST/STX), Teralink-X2, the Musiland 02US, stock HiFace, and the jkeny modded HiFace (MK1 and MK2) (https://sites.google.com/site/hifacemods/home/mk2-boxed-hiface-1)

With all of my DACs, the modded HiFace was the best by a large margin. I was surprised to learn that the USB/SPDIF conversion makes as big of a difference as the DAC itself in my system. The modded HiFace is very transparent...which what a USB/SPDIF bitperfect converter should be. It also sounds detailed and natural and has solid drivers.

Another option is the Audio-GD Digital Interface, but personally, I would exercise caution in purchasing from Audio-GD...build quality isn't the greatest and new products/revisions are released at a furious pace, making your new purchase obsolete quickly. Anyways, the DI also processes the signal so it's not even bit-perfect (though apparently it sounds pretty good). I don't want to take anything away from Kingwa from Audio-GD though...he is a great guy to deal with atleast.

My recommendation would be to give the battery modded (jkeny) HiFace a shot. He has suspended production but I saw a couple of units floating around in the sale forums on Head-Fi for cheap. Watch out for customs thinking the batteries are bomb-related though...they ripped apart a jkeny HiFace MK2 I shipped to the US...though I guess that's more to do with Homeland security in the States...

Edited April 15, 2011 by Shahrose

[NwAvGuy]

Just a footnote to this thread... If this guy's measurements are to be trusted, the Halide Bridge does offer measurably better performance over the direct USB connection using the Cambridge DacMagic:

Halide Bridge Tested on DacMagic

His results, however, could be specific only to that DAC. I suspect there are plenty of other DACs that wouldn't have the jitter problems in the first place.

[Ben Gramain]

Have you thought about something like the Fireface UC? http://www.rme-audio.de/en_products_fireface_uc.php

The Totalmix might have a slight learning curve but the signal routing capabilities are excellent. Quality is generally class-leading from my experience of the other interfaces and any of these IMO is a nice piece of it.

Unfortunately it's the only USB/Firewire interface from RME that I *don't* own but I have no complaints about the rest of the lineup.

It may even be feasible as a direct feed into your KGSS.

Edited April 21, 2011 by Ben Gramain

[deepak]

Birgir get a Squeezebox Touch install the software on a random PC with all your music and forget about this USB nonsense

Touch will do 24/96 through digital out, it has been rock solid for several months here

[spritzer]

But the USB allows me to use any software I want and feed 4 dacs at the same time. Who said it was easy being a gear whore...

[PFKMan23]

But the USB allows me to use any software I want and feed 4 dacs at the same time. Who said it was easy being a gear whore...

So what did you end up getting?

[spritzer]

Nothing yet. I'm spending 12+ hours a day at work so this is on hold until things cool down a bit. I'll probably get the M2Tech Evo and build some nice PSU for it.

[Ben Gramain]

No interest for the RME? You'll get e.g the multiple outs you wanted.

Edited April 21, 2011 by Ben Gramain

[Filburt]

Just a footnote to this thread... If this guy's measurements are to be trusted, the Halide Bridge does offer measurably better performance over the direct USB connection using the Cambridge DacMagic:

Halide Bridge Tested on DacMagic

His results, however, could be specific only to that DAC. I suspect there are plenty of other DACs that wouldn't have the jitter problems in the first place.

I just glanced at this real quick but it sort of looks like there's a digital PLL and the resolution stinks and so you get that periodic behavior.

[NwAvGuy]

I just glanced at this real quick but it sort of looks like there's a digital PLL and the resolution stinks and so you get that periodic behavior.

Yeah, something weird is going on either with his PC, or with the DacMagic in those tests. I agree a poorly designed PLL could do that. It's like it's using two clocks and has to drop samples periodically when the relative sync error becomes too great to correct? A PLL, of course, is supposed to prevent such things not cause them.

I'm working on a blog article about Async USB, vs ASRC (Async Sample Rate Conversion) vs the more typical adaptive USB + PLL techniques. There's been quite a bit already written, but it's rather scattered and much of it biased around how a particular manufacture does it. And some of it is just plain wrong.

The world is clearly moving away from CD's so but there's still, by comparison, a lack of good information about what matters most when trying to play content off a PC, storage appliance, streamed from the cloud, etc.

[padam]

The Stereophile review has some measurements as well

[Filburt]

Yeah, something weird is going on either with his PC, or with the DacMagic in those tests. I agree a poorly designed PLL could do that. It's like it's using two clocks and has to drop samples periodically when the relative sync error becomes too great to correct? A PLL, of course, is supposed to prevent such things not cause them.

You can get periodic drift/pull behavior with DPLLs because accuracy is bounded by its resolution. So, it drifts until it passes a boundary, then snaps back. With that said, I'm used to seeing a somewhat different behavior than is depicted (and at a lower magnitude), so it could be a combination of factors that is producing this effect. Could also be, as you said, a problem with the host.

Edited April 24, 2011 by Filburt

[mypasswordis]

So something like Bresenham's algorithm applied to DPLLs?

[NwAvGuy]

Generally the more boxes involved (different PC hardware, operating systems, drivers, "bridges", DACs, etc.) the less likely it will all play nice together at all sample rates, bit depths, etc. While products like the Halide Bridge might work magic in one set up, in another it might amount to overpriced snake oil and offer zero benefit over the much cheaper V-Link.

I personally think most are generally better off with as much of a "one box" solution as possible. That way one designer had control over much more of the data/clock/signal path and if say J.A. at Stereophile verifies it all works right, it probably will also work right for whoever buys it. The same can't be said of mixing and matching digital hardware. Even in the pro-sound world there are frequent compatibility issues. And few have the ability to run tests that properly show jitter problems, etc.

Excluding a few "roll your own" custom FPGA solutions, I can almost count the Class 1 and Class 2 USB Audio 24/96 "chip" solutions on one hand including a few Taiwan manufactures with little convincing public data available for their parts. Most of the better known products are all using variations of the same few chips and some are even using the exact same code (i.e. from Centrance). The implementation certainly matters, but each chip ultimately can only do so much.

That's a long way of saying some of the 24/96 USB products might be more alike than many realize. Hopefully there will be more and better parts on the market soon. Right now the pickings are rather slim. But I would still put more faith in a decent USB DAC that's known to work well. I think S/PDIF's days are numbered along with optical disc transports.

[Filburt]

I think that's a reasonable take, although solutions which appear to utilize something based on standard UMS protocol (what I understand the "no drivers" solutions to be?) seem to experience the fewest problems. Aside from that, I think in general people worry too much about jitter. In terms of audibility, I think analog output stage design makes a bigger difference and that's where a lot of products are lacking (including USB DACs).

[Shahrose]

I agree. Matches my experience. (NwAvGuy / Filburt).

[Filburt]

So this is interesting - http://www.psaudio.com/ps/forum/viewthread/854/

[spritzer]

Indeed. One has to wonder if this is also true for the Evo...

[Filburt]

Is there any indication that the Evo is different architecturally from the hiface on the USB interface side? When I read the m2tech site it doesn't exactly sound like it is but I can't really tell. Would have been nice if McGowan had given more detail.

[spritzer]

Could very well be the same as such is so often the case. This is the best internal pic I could find of the Evo...

[trevorlane]

I'm not sure what static noise they're talking about. I haven't heard it through the SDS/LCD-2 or the KGSS/O2. I've got my Mac Pro running Fidelia > Evo/AES > D2D/I2se > SFD-2. I bought a ST cable but it's probably wrong (it's a simplex, single mode) because the D2D doesn't get any sort of signal lock from the Evo. Only major qualm I have is that compared to the Mac Pro toslink out, the Evo has about a half second delay with audio and video sync on movies. I've also run it from toslink from the Evo to the DAC, still no static, but the delay is there. I've had the same results running the Evo directly to the Hertsens DAC as well.

Edited April 30, 2011 by trevorlane

[ManBeard]

I've never experienced any static with either the normal Hiface or the Evo. Nor did I have any of the driver issues that guy had with Win 7 64.

I wasn't too impressed with the normal Hiface. It didn't sound much different from the USB input on an old el-cheapo DAC that I had. The Evo on the other hand was a noticeable improvement over the Hiface. Overall I'm happy with the Evo. It does what I need it to do and seems to do it well.

[Shahrose]

1) I've never experienced any static with either the normal Hiface or the Evo. Nor did I have any of the driver issues that guy had with Win 7 64.

2) I wasn't too impressed with the normal Hiface.

Same.

Edited May 1, 2011 by Shahrose