I was looking around last night and found this:
http://www.behringer.com/FCV100/index.cfm?lang=ENGIn the manual it mentions it providing a CV output. Since it has an internal power source this certainly is possible, however it doesn't give specifications anywhere as to the voltage range. I'll probably get one to test and also will see if improvements can be made to the audio circuitry. It has a VCA audio signal path so it will be interesting to dig inside and see what's there.
Ivan