Circuit Bending

Casio MT-205

Due to its 'super drums' variations, the MT-205 offers a load of interesting drum-patterns which are played with the usual Casio PCM drum sounds. The patterns and sounds correspond to those of the MT-500. The bass and chord sounds vary depending on their settings (3 possibilities per preset) and sound kinda thin. They don't have the interesting flair of the MT-68/100/400 series, nor the warm, analog character of the MT-500, but in combination with the rather minimal, preprogrammed patterns, interesting figures emerge.

The possibilities for modification are astoundingly vast, and so I managed to pitch the PCM drums to the extreme not by manipulating the drum sounds themselves, but only by tampering with the sampling frequency. However, the change in frequency reacts rigorously nonlinear in relation to the change in resistor value, so I spread the up- and down-pitching onto 2 pots to get a good control range for each. The open multichip architecture asks for a matrix circuit to get new ('wrecked') beat variations. I've built in the following modifications up to now:

• Controller for 'up-pitching'
• Controller for 'down-pitching'
• Changeover switch for up- and down-pitching
• Mute switch for bass
• Mute switch for chords

Sound example