stylophone mod

[Dave Krooshof]

So.
I bought a stylophone. It's a little organ that uses a pen to close the
circuit, rather then a bunch of real switches. The print is visible through
a hole in the box, and on it is a grafic representation of a pianokeyboard,
in metal, some 12 cm wide for 1.5 oktave. Toughing the keys with a pen does
the trick.
NB: Between all keyfields and the pen, the 9 volt batterypower is here. So
the actual keyingcircuit is not a standard resistorbank. Or am I wrong?

As it is far from a synthesizer, I feel like needing a few modifications.

0. The frequency down with 1 or even 2 okatves. It will probably mean
cutting out a R and solder a pot in somewhere.

1. Portamento.
Sliding the pen over the keys does: plidididididoo. I need it to do pliiiiioo.
So I figure I need a capacitor somewhere, to hold the CV for a while.
If the side effect is that every note will go down after release: Exellent.
I'll make a not-holding switch for it.
Any hints on where I will want the cap and what the value could be?

2. a frequency wheel/knob.
So far, I noticed that if I switch the device off while playing, it nicely
drops in tone. Good. So to safe these old components, I want to find a spot
that a) does drop the frequency, but does not hurt the electronics. Any
hints?

3. Dirt
So, back in the tough the electronics topic!
I definitely need some dirt in this machine. Toughing the keys lightly does
sound dirty already, as it's switching on and off all the time (noise
modulation).
Any ideas?


Dave -stylophone newbie- krooshof

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Dave Krooshof http://www.xs4all.nl/~krooshof
geluidstechnicus @ http://www.ahk.nl/the/theatertechniek_ov.html
webmaster: http://www.popronde.nl
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