MOTM

Anyone use multiple frequency shifters?

I'm just curious if you could do something like

OSC1 -> FREQ1 -> VCF -> FREQ2

and somehow get the cv where if you shifted FREQ1 up by 5hz, FREQ2 
would go down by 5Hz.   

It seems like you could have a voltage controlled slope of the VCF 
since you're changing the relationship of the harmonics going to the 
VCF then restoring the harmonics in the second frequency shifter.

Larry