ICL8038 oscillator CV Input

Discussion in 'The Projects Forum' started by nonsuchpro, Jun 22, 2014.

  1. nonsuchpro

    Thread Starter New Member

    May 31, 2013
    15
    0
    Hello all.
    I'm working on adding a 1v per octave CV in point for the ICL8038 chip. Right now, I have built the schematic below and it works as it should but obviously all I can do is sweep the a pot to change the pitch. I have just acquired a keyboard with CV outputs for pitch + key follow, and gate. I since have messed around with trying to get the two to talk and play nice but I'm not getting great results. I found I needed an additional trimmer to calibrate the oscillator (which is pretty neat because I can set it to change pitch a little as a cent up to whatever) across the keyboard. Now that being said, it works but the keyboard plays in reverse and I have tried to reverse the wires and then it doesn't play at all.

    So I guess my question is: Where is the best patch points for what I want to do on the schematic? Also, do I need say, a VCA or (?) in front of the oscillator? I've made many "drone" machines but now I'd like to give them all a CV in to play them off a keyboard. Hope I've made sense.

    Thanks in advance!
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,979
    744
    Pin 8 is the voltage sweep input, by putting different voltages on this pin will give different frequencies. If your keyboard gives out a different voltage step for each key i would start by putting it on pin 8 and ground pin 11.

    datasheet


    linear Vco
     
    nonsuchpro likes this.
  3. nonsuchpro

    Thread Starter New Member

    May 31, 2013
    15
    0
    Thanks.

    I've build this circuit and it is much better.
     
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