empirical audio or lynx aes 16 sound card

15 feet is supposed to be the limit for usb cables, unless you get something like an Opticis optical usb cable. I had the same issue, went with the Opticis for a while, but it had trouble with 24 bit data streams. I now have a mac mini on my stereo rack connected to an Empirical Audio Offramp that feeds the digital input of my Wadia 860x cdp. Having the mac mini on my rack means I can use a short usb cable. Buy a good one as they do make a difference.
As to the Lynx sound card, I suppose you could run a 20 foot (7 meters?)length of aes/ebu cable to the stereo...

Forgot to mention, I runs an S-video cable from my mac mini (using a DVI-to-video adapter) to my TV, and can use the tv as monitor for the mac mini. So, no unsightly monitor on the stereo rack.

You can run a long AES/EBU cable from either of these. Long cables are not exactly a great thing but the higher voltage of AES/EBU is the better way to go - even better than a long toslink.

I found the Empirical Offramp 3 with Superclock 4 to sound a touch better than the Lynx aes16. The Lynx sounding a little flatter, the Offramp a little more vivid.

IMO, the answer is it depends on one thing: If you are using a DAC that doesn't do 2-dimensional jitter reduction, then I recommend using the EA converter. If you use a DAC that does 2-D jitter reduction, then it doesn't matter whether you use USB (with or without the Empirical Audio converter) or AES out of the sound card.

I have a 30 meter Opticis USB cable from my PC to my rig. I also have an 80 foot AES cable, plugged into Lynx AES16, from PC to rig. And I have an EA Turbo2 that I can use to convert USB to AES, if needed.

Until recently, I used a Meitner DCC2se dac. It sounded better when I ran USB through the EA Turbo2 compared to when I ran AES from the Lynx directly into the dac. In fact, the sound with USB+Turbo2 was equal to using my Meitner CDSDse transport. So I ended up getting rid of the transport because I never used it. I believe the USB+Turbo2 sounded better because it had lower jitter than Lynx+AES.

Moving forward to present day, I now have a Playback Designs MPD-5 dac. The PD dac uses 2-D jitter reduction, so it doesn't matter what kind of digital signal you use. Whether I use Lynx+AES or USB+Turbo2 or USB directly into the dac, it always sound the same. To me this is a game changer. There is no need for expensive converters or worrying about which signal to output from your PC. My strategy was to save the money that I would have spent on an expensive converter and put it toward a better dac that doesn't need the converter.

That must be a very good DAC. But a claim to be completely immune to jitter is a very big one, and one that has many times before been made, only to prove to be untrue.

I would be very interested to hear more about the so-called 2-D jitter reduction. I read what is said on their site and it is pretty obtuse, but you get that with web sites - it doesn't mean they are not onto something.

Reading between the lines, they seem to be using the same jitter reduction process as used in a number of DACs, but maybe with a twist. I am guessing they are doing the over-sampling trick used by Bel Canto and Benchmark, where you upsample to a very high rate and then downsample just before the DAC chip. While this more or less eliminates jitter it simply maps jitter to broadband noise - ie jitter turns up as bit errors. The sound is at first impressive but ultimately sounds unnatural, particularly timbres of real instruments.

The process can also add errors due to any imprecision at the very high clock rates used. What they appear to be hinting at is that they do the same thing as say the Benchmark but then fix the bit errors. This is conceptually possible since the original jittery signal can be used as a reference, since it is likely to be bit perfect. But there is a "so what" here. Eliminating jitter is theoretically possible without using this particular strategy. There are many such strategies, and using ethernet for bit transport is probably the most promising of them. The tough thing is implementing it in real time, and the ethernet products we know like the Logitech products are not at all perfect. So far, I don't think anyone has done it, including Wavelength with their asynchronous USB, but it would be a massive breakthrough if someone did.

I wouldn't throw around the "must be a 2-D DAC" mantra too much. All they are saying is the DAC should attempt to eliminate jitter - that is all they mean by 2-D. Therefore there are a lot of 2-D DACs out there. Their implication that no other DAC attempts to deal with timing issues is not a fair comment. The only interesting thing, is their implementation - if it does indeed work as completely as they claim.

From your comments Big-amp, they have had some success. Experience to date makes me remain a skeptic about the claims of complete elimination of jitter, for the moment at least - but I now want to listen to one of these DACs, if I can get my hands on one at this end of the world.