Buffer setting in the M-Audio control panel is 256; the default.
Thought I saw a slight level reduction in Chops.wav, when the choppy sound begins. But looking at it now, with fresh eyes, does not reveal anything like that. Strange that the choppiness does not really appear in the waveform display.
And in Audacity Recording Preferences? Is it still increased to 1000?
Do you have Transport > Software Playthrough on? That means the buffer setting has no effect.
Gale
Software playthrough is unchecked, and I’ve reset the latency setting in Audacity to 100ms, since the choppiness does not appear when set to 1000 ms.