Yes, I can help.
Is it the same flac file dropping the audio? You said for about half a second so that means it instantly comes back and continues to play? So far has this only occurred once per play or if you leave it on longer than 10 minutes looping a number of flacs it occurs again?
Any flac file will do it in my experience (
sendspace link), and it is program/playback indescriminate. I just have a file I've constructed (tone and pulse) to make it easier to visually verify without listening when it occurs. It only occurs when using the USB playback (and affects all outputs). I've tried feeding it an optical signal with great success, so it's something related to the USB signal.
The original email I sent to SD:
occasionally (with no consistency of frequency) when
playing back audio to the usbpre2, I experience a momentary dropout of
sound, approximately 1/8 to 1/4th of a second in duration.
Firmware: 1.01
Operating System; OSX, 10.5.8
Operation; playback over usb (has not occurred over optical, no way to
test SPDIF on this machine)
Powering: Does not lose power (metering decays appropriately during
dropout and resumes when signal is returned.)
Buffer: I've increased the buffer on my playback program from 2000ms
to 4000 and then 10000ms with no improvement. Frequency or consistency
of occurrence does not change (both are still at random).
Occurs when running nothing else after rebooting and when running all
sorts of stuff. I have a USB hard drive attached, a usb keyboard,
mouse, and the usbpre2. I've tried inducing load on the hard drive,
keyboard and mouse all simultaneously (to proverbially "starve" the
usbpre2 due to traffic over usb) to no avail. I can occur as
frequently as once every 3 minutes or as infrequently as once every
couple of hours. Do you have any tips on trying recreate it with
consistency or to isolate whether it's the usb data traffic, the usb
power (although unlikely due to the decay demonstrated), or something
else?
edit: added sendspace link.