Yes, me. The very same symptoms you describe also happen when connecting my iMac via USB to my Schiit Bifrost DAC. I purchased a special USB galvanic isolator, which makes the problem even worse: With this galvanic isolator the time until the static screeching returned was much shorter than without this device. Trying another USB port didn’t help.
Switched back to an optical Toslink connection. If I would have known this before I placed my order I could have saved the US$ 100.- for the Bifrost USB option.
Thanks for the info Werner. I'm not certain where the static stems from. With other dacs, I never had issue with the particular usb port I was using when the static appeared. I've switched ports and will see if I can replicate the problem.
Btw, I'm still using Snow Leopard and suspect the Lion issue with usb (powered?) dacs may be unrelated.
Have any non mac users encountered this problem?
Tried another usb port and had no issue for about a day. Loaded up iTunes/BitPerfect and the first song degraded to static screeching halfway through. Went back to Fidelia again and no issue for a while until this afternoon. There doesn't seem a set amount of time before the sq degrades and I haven't identified how to replicate the issue. I'll test the optical input next.
edit: Optical is nice! Not as warm as the usb input (which I usually prefer), but it sounds clearer, more extended in the top end. The overall presentation is noticeably more coherent than usb, with a better sense of depth and imaging. Anticipating some glare and edginess depending on track, but have yet to encounter it.
Edited by olor1n - 1/29/12 at 11:47pm