hey matriv,
i've bent an mt-205. i got it at a flea market and loved the drum slide switches. looks like there are a few nice bends in this thing...
the most extensive bend i found was shorting the pins on what is probably the drum chip. i'm not sure since it's on the other side of the board and i just soldered to the pins of it, but if you're looking at the mt-205 board from the side of the keys, you'll see a surface-mounted chip - mine says something like "HD617....". to the right of that is a series of 12 aligned pins parallel to another series of 12 pins. shorting those pins will give some weird drum glitches, and also some not-too-exciting keyboard glitches.
i created a patch bay for that bend using RCA jacks, and put a female serial jack on the keyboard and a male serial plug on the patch bay, to make it detachable.
found a couple other bends as well... two that give really raunchy distortion when you play keys while the keyboard is in "fingered" or "chord" mode.
found four bend spots that'll repeat a note over and over - when you engage more than one at a time it speeds up the repetitions.
and a couple other drum glitches that aren't very exciting.
i'd be interested in trying the distortion for the drums, do you know which components you connected?
if you can upload a picture of the PC board, i'll map out the bends that i mentioned. my board is too cluttered with wires to use as a map, can't see a lot of the pins. would appreciate it if you and AttDestroyers posted your mods as well...
-vito