Project Terpsichord Part 2

Terpsichord keyboard test fit

The next step in this project is a bit of research. I don’t really know much about this little keyboard I’m bending. The Internet knows many things.


First, it seems like I’m about the only person referring to “Steampunk circuit-bending” as “steambending”. Whereas “steam bending” is a real thing you do to…wood or something. So maybe it’s not a good name?

Next, some fascinating news from

“In 1981 Casio made the VL-Tone 1 (VL-1), a small, monophonic synthesizer with built-in calculator. The “M+” calculator memory also stored the timbre, ADSR, vibrato and tremolo setting for the synthesizer, and the short 29 buttons mini- keyboard could be transposed by a switch to low, mid and high pitch range.”

“Due to it seems to contains still the same CPU like the VL-1, it must be possible to add the synthesizer and the other missing features of it again to the PT-1.”

Now wouldn’t THAT be nice? I might eventually be able to bend this four-sound toy into a VL-TONE with real patch editing and keyboard transposing? Awesomer and awesome, cried Alice!

But that’s for the distant future. Meanwhile, reading on….

Wikipedia says:

“The VL-1 was the first instrument of Casio’s VL-Tone product line, and is sometimes referred to as the VL-Tone.”

The “VL-1 is notable for its kitsch value among electronic musicians, due to its cheap construction and its unrealistic, uniquely low-fidelity sounds.”

Here’s an online copy of the VL-1’s user manual, describing the programming (calculator) mode and the other features.

I can’t find a PT-1 manual online so far, but reading between the lines of the VL-1 manual should be a pretty good step toward understanding what the buttons do, etc.

Meanwhile, I’m not the first person to rework old synths. I found some fun stuff on YouTube:

This circuit-bent PT-1 gives me hope that I could make this thing sound actually good:

This stunning circuit-bent Casio SK-1 is true Steampunk, in a way that mine probably won’t ever be. The sequencer appears to be electromechanical, a sort of motorized commutator:

Of course, a search for “steampunk synthesizer” reveals a variety of nice toys. Here are a few really elaborate ones:

Really beautiful. Check ’em out.

…And that’s enough research for now. Main conclusion: it may be much easier and faster than I expected to circuit-bend this synth for improved sound. Very interesting indeed!