One of the coolest things about the DM-2 is the oscillations you can get when you crank the intensity and echo knobs and vary the Repeat rate in real time. Start with the repeat rate knob @ 0 and the other two knobs cranked. Hit a note and then reach down and slowly crank the repeat knob until all hell breaks loose. The self-oscillation that occurs must be heard to be believed!
You can get a lot of different sounds if you fiddle around with the knobs for a while. I recorded 30 seconds of this for anyones enjoyment/pain. Here it is:
There's a good example of the DM2 oscillation on the first album by the Rev. Horton Heat also. I can't remember which song it is, but it's one of the instrumental tracks. Maybe "Psychobilly Freakout" or "Marijuana".