BBB Audio playback issues

Using a number of different programs to play audio, I'm finding some glitching with the audio output from my BeagleBone Black. The simplest case is the ALSA speaker-test program. I'm playing audio through an audio-technica ATR2USB dongle. This same dongle works fine on OS X and Ubuntu in a VM on OS X with speaker-test.

I think the glitches are the result of buffer underruns. I've tried specifying larger buffers to the various tools, all to no avail. Some feedback suggested I look at CPU load and for errors in the logs or interrupt contention, but looking in /var/log and at /proc/interrupt, nothing immediately jumped out as problematic. CPU load is very low.

I'm going to try using the HDMI audio output when I get home, to see if it has similar output issues, but I'm not sure how hard this will be to try.

Any other suggestions?

Thank you,