Combined voltage controlled amplifier and mixer design

I have decided to combine the voltage controlled amplifier and mixer modules from Music From Outer Space, into a hybrid voltage controlled mixer where each VCA can work either as an independent unit or the output can be added to a mixed output. The panning circuitry from the mixer has been removed and the audio output from 2 of the VCAs is fed directly onto the left and right audio buses.

There will be twelve VCAs in total grouped into pairs so that mono inputs can be fed into 2 seperate amplifiers to enable a panned stereo output.

Inputs for each 2-channel amplifier:

• 2x Audio inputs.
• 2x Control voltage inputs.

Outputs for each 2-channel amplifier:

• 2x Audio outputs.

Controls for each 2-channel amplifier:

• 1x Mono to stereo toggle switch - Enables mono signal to be fed into both channels.
• 1x Linear/Logarithmic scale toggle switch - Operates on both channels.
• 2x Level slider.
• 1x Add to mixer toggle switch.

Mixer output:

• 1x Mixed audio output.