I’m going to need a bunch of utility modules to make this system usable and moderately flexible.
First I’ll need some Voltage Controlled Amplifiers. I will try to make do with two dedicated VCAs (since the Z3000 oscillator has an in-built VCA) and am going with the Doepfer A-132-3 DVCA. This is a dual VCA with separately switchable control scales: linear (for CV amplification) and exponential (for audio amplification).
It is sometimes necessary to connect an output to more than one input. You might want the LFO to affect the filter cutoff of both oscillators for example. To do this you need a “one-in, many-out” module called a Multiple and I’ve picked the Doepfer A-182-1 Switched Multiple module for this task. The simplest multiple is just a bunch of jacks that are all connected to each other to form a bus. The A-182-1 multiple has two busses and eight jacks with switches that can connect each jack to bus 1, bus 2 or disconnect it from both busses. This makes it a little more flexible than a fixed multiple.
When using more than one oscillator or other sound source the audio outputs will need to be mixed at some point. I could do this with an external mixer but I think the system will be a lot easier to work with if it has at least a simple audio mixer built-in. The Doepfer A-138b Mixer is a simple four-channel mixer which should do the job. The ‘b’ means that the pots are exponential which is what you want for audio. Consequently there is a A-138a as well on which the pots are linear and more suitable for CV mixing but I don’t think I’ll need that (famous last words).
1 Doepfer A-182-1 Switched Multiple
1 Doepfer A-138b Mixer
1 Doepfer A-132-3 Dual Voltage Controlled Amplifier
1 Doepfer A-114 Dual Ring Modulator