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I have been building some noisemakers using cardboard as pcb. It´s a nice material for building electronic projects at home because: 1. everybody may not have the needed equipment to make "real" pcb:s 2. every one has a piece of cardboard laying around. 3. It is cheap and easy. This is my latest creation on cardboard pcb. It´s wp-20 sound effects synth. It was very nice to do on cardboard because there was enough spce between components in the original pcb design.
I did´t use the original noise source with 18v but i built a simple 9v noise generator. I left q1, r1, c3 unconnected to the board. here is the noise circuit.
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Testing wp-20 video:
link to music from outer space wp-20 page:
I made a sub oscillator for my wp-20. It is based on cd4040 ripple counter it uses the vco squarewave (before the 100k resistor marked R8 in the original wp20 schematics) as clock input and divides it. Six switches (from 1 octave down to 6 octave down) select the harmonics to vcf-vca. The circuit is quite simple the component values may be tweaked to get better performance. I used components that I happened to have so some different values might work better but these seem to work ok. (sub osc out is connected to ic 2b pin 6 through a 100k resistor like the vco) here is a picture of the circuit![](//2.bp.blogspot.com/_3FN-mabMHe8/Rx4pD4Aq-UI/AAAAAAAAACM/FeEh9APUP-0/s400/solderside.bmp)
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![](http://1.bp.blogspot.com/_3FN-mabMHe8/Rx4o4oAq-TI/AAAAAAAAACE/d6AHuZ6Saqo/s400/components.bmp)