Schematics / The XR-VCO Project
The XR-VCO Project by Thomas Henry ,visit Scott Stites page dedicated to this module with lot of construction details ,samples ,notes on calibrating the VCO and even tips on finding parts needed for this project http://www.birthofasynth.com/Thomas_Henry/Pages/XR-VCO.html
From the notes on the page :
The XR VCO is a voltage controlled oscillator based off of the XR2206 function generator IC. It was designed by Thomas Henry in June of 2006, and is presented here for the enjoyment of all. Feel free to build it, modify it and apply it to any of your DIY projects.
Features : V/Oct Input Coarse Tune Fine Tune Expo FM Input Linear FM Input Sync Input Pulse Output Switchable Tri/Ramp or Sine/Rampoid output Voltage Controlled Skew