DIY voltage controlled stereo mixer with variable linear/ exponential VCA response
The Voltage Controlled Stereo mixer can be built with as many channels as you like (shown as a 4 channel mixer) using the Voltage Controlled Mixer Channel PCBs and the Output Mixer PCB.
From the web site - Voltage Controlled Stereo Mixer:
The VCSM is an expansion of my Equal Power Panner with VC Gain added. The module swaps the THAT 2180 chips with THAT 2162 dual gain cells. Each channel has MANUAL and VC PAN, MANUAL GAIN, VC GAIN (VCA) and a variable response, manually adjusted from Linear to Exponential. Auxillary inputs are provided on the output mixer to add additional inputs.
These merchants probably sell this module. Huh?