Okay, well I went back and forth on enabling and disabling, moving back and forth on my git tree and the juce git tree. The modules branch complicates that, of course.
Still having a lot of trouble pinning it down. The output thread isn’t getting starved - I always have the right data for it, so possibly the buffer thread is innocent. I did suspect the resampling source, but tone is OK, and A/V sync is off, but seems consistent.
So - one thing I found is that when I cranked the output buffer size way, way up - max of the audio setup dialog - 42 ms, it starts to sound better. Still very choppy, but better. It was fine at 11 ms before.
So - it’s a Mac, OS 10.6, tip tip Juce. Did some thing happen in outputs or the mac audio output specifically?