Casio PT-87
Only one of these I ever came across and/or circuit bent. Really nice little instrument aesthetically, and it’s got the nice signature blippy voices and rhythms that are in the other lower numbered PT models.
Modifications:
Touch contact for pitch down/vibrato • Coarse pitch knob • Knobs for various distortions and sound modulations on both voice and Rhythm sections • RCA Video Output for CRT TVs • 1/8" Audio Output
2010.
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12/30/2020 Update:
In a bizarre turn of events I came across a photo by Vaporwave artist Skeleton Lipstick - with this keyboard in it! I got in touch and apparently they’re the original buyer and have been using this keyboard for the past ten years! Absolutely made my day. You can hear it in a number of tracks by them, including Happy in Disguise, Am I Close to the Edge?, and Philadelphia.
Casio PT-100
Two of these were built, with this being the one I was much happier with. The PT-100 lives in a weird in-between space. It's keys are mid-sized, yet it contains very little in the way of voices or rhythms. It also exists right between the PT and lower numbered MT keyboards in terms of stock sound options and internal circuitry. It's bulky for what it contains, but the modification options I found in it really give it some great and interesting abilities.
Modifications:
1/4" audio output jack • Internal Speaker on/off switch • Variable lead distortion knob • Dedicated variable distortion knobs for hi-hat, snare, bassline, kick drum/auxiliary percussion, and accompaniment chords• Starve knob • Squealing feedback/distortion body contacts • Sound pulse/warble switches • Crackly bass distortion optic theremin
2008.
Casio MT-205
More often than not I'm not as excited to run into higher numbered, larger model Casios. For me the appeal begins to lower the larger they are and the more stock options are added, especially when it comes to "realistic" sounding rhythm sections. This MT-205 was somewhat of an exception. It's between large and mid-size and it's rhythm section really lacks, but due to the stock availability of various "rhythm modifier" sliders there were some incredibly interesting findings in the circuitry that allowed for the seemingly random chaotic scrambling of stock rhythm arrangements. That was a main highlight for me, but also found were ways to generate some incredibly warm bass tones, distortions, pitch modulation controls, slight filters, and a slew of ways to make this thing perform in a way I haven't seen in any other devices.
Casio PT-10
This was my second attempt to circuit bend something very early on. Still learning to solder, still just dipping my toes into circuit bending. It was also a little keyboard that I just fell in love with. I've since owned a number of PT-10s and PT-1s due to the lovely clean tones they produce in such a compact size. There weren't all that many interesting options I found for bending, aside from one great switch that when activated makes any note "step" upward in a mario-type fashion once released, and there was hardly any room inside of the case. Still holds a special place in my heart.