What’s a stylophone? It’s a curious instrument from the 60’s, according to wikipedia
It consists of a metal keyboard made of printed circuit board and played by touching it with a stylus—each note being connected to a voltage-controlled oscillator via a different-value resistor—thus closing a circuit.
Got this reissue from an ebay auction together with a Stylophone Beatbox (whose bending will come in the next weeks).
Open it up!
There’s no screws, but the bottom is glued to the top and there are 4 plastic clips, 2 each short edge. I used a small flathead screwdriver to separate the two parts, paying attention to avoid clips breaking.
To access the front side of the board I unsoldered the stylus and the speaker (better take some pictures to remember where they were wired). Unscrew everything and…
After some probing I found that the majority of interesting points are reacable from the back of the board, so you can use them actually without unscrew everything, except for:
- low pin of R12 (for tremolos)
- Drone point (to enable drone mode)
So, i connected two wire to those points, and mounted the board again to the plastic front.
Here’s a list of my “sweet shorts” (point of view of the photo below, from left to right for the position numbers)
- Drone mode: drone point wired to the stylus pin. (switch to enable/disable)
- Tremolo: low pin of R12 wired with the third of the “5 pins”. (switch to enable/disable)
- Super Tremolo: low pin of R12 wired with the low “board pot” pin. Put a LDR between to control its speed with light. (switch to enable/disable)
- X: it’s a continuous high-pitched sound. Fourth of the “5 pins” wired with the third of the “mode pins”. 10K plus LDR to control the tone(switch to enable/disable)
- Filter: “R5 pin” wired with “Chip pin”. Put a 100K pot between to control the amount. (no need to switch, when pot is turned to full resistance the effect is absent)
- Robot: “R5 pin” wired with board pot hi pin with a LED in between. (switch to enable/disable)
- Pitch control: “R5 pin” wired with board pot hi pin. Put a 1M pot plus LDR.
There’s not a lot of space for components, but with some dodges it’s possible to fit everything in there.
I also added a DC plug to make the device work with 4,5V DC adapter.
Here’s how it looked after wiring
To improve fancyness, I added a fidget spinner to modulate LDR’s. And that’s all!