USB - SPDIF on Eastern Electric DAC


I've recently gotten the upgrade bug and am looking to replace the stock USB input of my EE DAC with an asynchronous converter. I've tried a few USB to SPDIF converters, namely the Halide Design
Bridge, and the Stello U2 (which isn't asynch) fed into the RCA SPDIF input of the DAC. I've been having
some issues with the sound dropping out suddenly every 30 seconds or so
with both units. This doesn't happen at all when I use the stock USB
input, but does happen in both the RCA and BNC inputs when fed by the
USB->SPDIF converter. At first I thought it might be because I was using
a long USB wire, and the USB-> SPDIF converters (both being passive
devices) weren't getting enough current from the USB port. However, I put a 1 amp powered USB hub into the equation and also tried shorter USB
cables, but am still having the same problem. Have anyone ever heard of this problem or know of any remedies? Also I am using a macbook pro with OSX 10.6.4 and itunes if that helps. I'm thinking of trying either the musical fidelity V-link or ART legato, but am wary that these will have the same problem. Has anyone had any luck with any usb to spdif on this dac. Thanks, greatly appreciated.

Ron
linaeum66
I am not going to ask why would you want to go this route (limiting yourself to only 24/96) instead of upgrading to a DAC with async USB built-in, (which could give you 24/192) but I'll ask this: Have you tried with another computer, just to eliminate the chance that what's happening is due to the computer/software?
"But actually, an external USB to SPDIF converter might outperform the device's own USB input?"

Some USB implementations are sub par...
I use the M2Tech Hiface and BNC into the EE Tube DAC and have never experienced any problems. I did have difficulty with a cheap DVD player and CD player via optical into the EE DAC, but once I used a high quality transport I consistently got a lock. Apparently the 9018 chip doesn't handle high jitter sources as well as the old chips. However, the sound is wonderful. I see no need to think about another DAC just to have 192 USB. Especially for the price of the EE DAC. So, to answer your question.....if the USB-SPDIF is located next to the computer, how long is the digital coax? What kind of digital coax are you using? Is it possible to temporarily move the computer and EE DAC close to each other and see if you maintain a lock? If all of that fails, contact Bill at Morningstar Imports ([email protected]). He has been very responsive to all of my emails and we have talked at length on the phone several times about audio and music. He is very friendly and helpful person and would want you to be happy with the unit.
USB converters/interfaces all use different drivers and firmware. Some have higher latency than others. Your computer must have a fast-responding I/O system in order to avoid drop-outs with some of these. I have personally had great results with Toshiba laptops and the Mac Mini. Terrible results with Dell. It can help to remove all other USB devices and kill virus scan and other unnecessary apps etc..

And the concept that an external USB converter (particularly async) might be better than the one built-in to your DAC is not so far-fetched.

Steve N.
Empirical Audio
If it is true that the 9018 chip is particularly sensitive to jitter, that may be the issue since the halide bridge and stello U2 both have jitter around 300-400ps. Has anyone else tried the EE dac with the hiface or other converter. I believe the hiface has only around 45 ps of jitter, so it may be worth a shot.