[sdiy] LFO's showing up on VCO

[Dan Snazelle]

I am not sure of the technical name for the problem of circuits (lfo's especially) influencing your Main VCO'/'s, but it's a problem i have had before. The difference this time is I am working with a pcb (asm2) that 
has all of the circuits on ONE board, utilizing a single PSU but with a +/-10 v reference for the VCO. ( i had hoped the reference would get rid of this sort of problem)

Now that all the circuits are working, i am finding myself pulling out my hair due to HEARING the other periodic circuits making my VCO output unstable. (even with the CV's disconnected, i can still hear them messing with the waveform)

at this point i am not willing to add a second power supply to this board and i dont think it would fit anyway.

SO...i am looking for ideas. 
I tried removing the LEDS attached to the LFO  but that didnt seem to help. 
HOWEVER i am wondering if giving the LEDS their own ground (straight to the PSU) would help.





I am using a power one +/- 15 volt supply

here is the link to the circuits:
http://www.elby-designs.com/asm-2/asm2.htm

thanks so much