Hi all , im building a drum synthesiser from scratch and all my filters vca ect are operational , but i have a few 555 chips that i wouldnt mind using for vcos ,, trouble is i cant find a schematic that shows how to apply a variable voltage to change the pitch , ideally i would like a frequency dial pot aswell as a fm input for sweeping bassdrums percussion if you get me....
any help would be much appreciated .... javascript:emoticon(':D')
Well, anything with a variable resistor (like a 555 oscillator) can be made voltage controlled if you use a vactrol or H11F3. It's been brought up a bunch of times here, so try a search. The 555 also has a VC pin, pin 5, so you could try using that as done here
http://www.robthefiddler.com/electronic ... 55-as-vco/ and
http://www.ecelab.com/circuit-vco-555.htm -Colin
