I had a midi quad/abacus and some of the patches engaged 2 channels at one time. I also took a 1 ft. 1/4inch patch cable and plugged two together, like ld1/ld2 to get a slightly chunkier rhythm, but it wasn't a huge difference. I also tried getting it to use my GSP 2101 in the loop and from the outputs of the quad, but never got a useable result. It was almost inaudible. I did flip the Line/level switch on the back, but didn't really do anything. there could have been an issue with the quad, but I don't think there was. I ended up selling it and simplifying with a head unit. It was a really cool unit... great sounding, and would have liked to hold on to it and the abacus, but oh well. oh and yeah the mk IIC channel was louder than the mk III channel.
scott