Casio MT-55

The Casio MT-55 is one of the keyboards that really got me started in circuit bending. It's got the perfect combination of cheezy-yet-usable stock sounds and the medium-key size, 6 note polyphony, and octave range make it a very practical choice for playing. In addition, the possibilities for modification are massive. The sounds I've found in circuit bending it really expand its abilities and make it a beast of a mini synth.

Moogfest 2016 Circuit Bending Competition Entry

Modifications:

1/4" Audio output jack with volume knob • Internal speaker on/off • 2x variable noise/bass tone generators • Variable lead distortion knob • Optic theremin to control lead distortion • High pass/wah/squeaky mod on/off • Two body contacts to create loud squealing feedback and distortion, also able to pickup radio interference using human body as antenna • Coarse pitch adjustment with on/off latching button • 'Crazy child' switch - chaotically triggers notes within a specific key • 7x switches for sending various distortions to dedicated rhythm and accompaniment sounds

LFO containing: On/Off, Knobs for Rate, Shape (Triangle to Square), and Depth, ability to send to either pitch or distortion.

Built as an entry for Moogfest's Fifth Annual Circuit Bending Competition for 2016.

Progress Photos Video Overview

Untouched

Internals

Making room for additional controls

LFO

Thank you Casper Electronics for the easy-to-implement design!

LFO building

LFO Success

Time to paint

I love blue and green. Lovelovelove.

Didn't plan this spot out too well.

Colored angel hair pasta

No matter what I do...

I always seem to end up losing any attempts I made to keep the internal wiring pretty

Schematics • Bill of Materials

The Unicorn / 2016

Commissioned build and paint. Having been eight years since my previous two MT-55s it was exciting to revisit one of my favorite devices and discover new possibilities for it. That, and making this thing as rainbow-tastic as possible per client request was fun.

Modifications:

LFO containing: On/Off, Knobs for Rate, Shape (Triangle to Square), and Depth, ability to send to either pitch or distortion.

2016.

The Original / 2008

The first keyboard I circuit bent and added additional controls to was the MT-55. The above gallery on the left shows the original, and the gallery on the right shows a replica of that keyboard. The replica was sold to the band Persephone's Bees.

Modifications:

Variable lead distortion knob with hard on/off switch • Highpass/wahwah/squeaky mod on/off • 6x switches for sending various distortion styles to to Kick, Aux percussion, Snare, Hihat, and accompaniment chords/bassline • Rhythm low pass/Kick distortion/Hihat Reverse • Blippy auxiliary percussion on/off • 2x Noise/Bass tone generators • Two body contacts to create loud squealing feedback and distortion, also able to pickup radio interference using human body as antenna • Unstable pitch down