After trying a couple of inexpensive DAC/headphone amp combos, I decided I liked the sound of the HiFiMan EF2A, and wanted to make it my primary portable DAC/amp for the moment. Unfortunately, it seems to be causing a very disturbing problem. Now and then, the sound will either stop entirely, or worse, a loud static will suddenly begin.
1) If the sound simply stops entirely, in order to restore any sound at all, I have to unplug the USB cable, reinsert it, then restart playback. Until it happens again.
2) If the static thing happens (instead of silence), I can stop what's currently playing and restart it without unplugging the USB cable, but if I don't unplug/reinsert the USB cable, there will be some level of background static during resumed playback.
This doesn't happen when I'm playing music through the speakers (in this case, USB digital output to Schiit Bifrost DAC, then to amp), or with my other portable DAC/amp, an Audioengine D1. Only seems to happen with the HiFiMan EF2A. This is really unfortunate, because this was my preferred choice in terms of sound quality for the portable headphone kit.
I'm currently using Foobar 2000 for playback on Windows 7. Just to be sure it wasn't Foobar, I tried it on WinAmp as well, and the same thing happened. In any event, I'm not sure I have all the correct settings in either Foobar or Windows "Sound" (control panel), but this problem does seem to happen only when using the EF2A.
Has anyone experienced this issue with this particular DAC/amp? Any suggestions?