Yes, I am. It's the default kernel in Ubuntu Studio. I get almost no
Xruns in JACK too, so as far as I know, its a separate problem. I have
noticed though that one of the few times I'll get one or two Xruns is
when I switch instruments within ZynAddSubFX. Not sure if that matters.
In case its helpful, here's some of my JACK settings:
Realtime: checked
Monitor: checked
H/W Monitor: checked
H/W Meter: checked (I'm not sure why I have these last two boxes checked, does it matter?)
Frames/Period: 64 (I've tried 128 too, and that didn't seem to change anything with ZynAdd)
MIDI Driver: seq
Sample Rate: 48000
Periods/Buffer: 2
Port Maximum: 256
Timeout: 500
As for ZynAddSubFX settings, here's some of the relevant ones:
Sample Rate: 48000
Buffer Size: 256
OscilSize: 512
PADsynth Interpolation: Linear (fast)
Append: checked
XML compression level: 3