Circuit Bending

Casio MT-56

As far as I could compare, the MT-56 is the fully developed version of the MT-36 with 8 beats and 8 melody sounds. Still, not all of the auto accompaniment ICs' pins have been made use of, so I guess that a lot more functions should be possible.

The drum sounds are very similar to those on the Casio MT-55, electronic and analog, although their generation is only partly analog. Same thing goes for the square wave bass sound and the chords. The BD and the toms are generated from square wave signals which rely on digital control signals that hardly allow tampering. The HH and snare sounds are rendered with the bass sound from one IC pin, making manipulation or seperation close to impossible. Same thing goes for the chord section, which can only be muted or slightly distorted.

My modifications are similar to those on the MT-55, enhanced by a pitch controller:

• Mute and distortion switch for bd and toms respectively percussions
• Mute and distortion switch for SN, HH and bass
• Mute and distortion switch for chords
• Pitch controller

Sound example