Try looking for a Princeton Applied Research CR-4. This is a completely insane-sounding scientific instrumentation amplifier, with three input configurations and low and highpass filters switchable in 5ths.

Anything processed through one of these takes on a vicious psychedelic tone...totally overloaded, brutal, and the filters just add to this. The only caveat is that these are obsolete test equipment devices, and not musical ones per se. Even so, to use Hainbach's term (he also owns one), it will 100% music! You should keep an eye on eBay for one of these; they can turn a basic synth into something that sounds like it might KILL YOU.