The DB-25 multi-pin connector on the back of the ASM has essentially not yet come of age. Marion Systems is planning on coming out with an interface for it, probably adapting to 1/4" jacks.

The intention is that the user could substitute the internal waves (saw, triangle, etc.) with any audio signal, appearing just after the oscillator output, allowing all of the processing from the filters and back. To accomplish this, however, there are some special considerations in regards to triggering the audio source via MIDI, etc.. So, it may possibly be that only MIDI equipped instruments will have the luxury of this kind of access.