Synthi VCS3(mk2) External CV and Gate Interface Unit
Pictured above is a VCS3 mk2 external CV and gate interface module.
Custom designed with hand made afrormosia hardwood case as in the original VCS3 and original synthi knobs/sockets/styling and custom engraved panels. Different knob colour options will be available. It allows individual switching of the 4 channels (Input ch1, Input ch2, matrix row 16 (joystick vertical control) and gate) between either external CV1-CV3, gate (via 6.35mm jacks) or DK1/2 function.
Another nice feature is it also allows the on board Oscillator in the DK1/2 to be routed in and out to external effects/filters etc before re-entering the matrix via input channel 1. This means that you can apply external effects (echo, reverb, filtering etc) of this Osc independently of the main synthi Osc1-3. The unit has two cables permanently connected, one connects to the DK1/2 Keyboard via 8 pin female socket and the other to the VCS3 via 8 pin male Jones plug.
The unit features precision 25-turn trimmers accessible from
the rear that allow precise adjustment of the 0.32V/Oct CV scaling
opposed to the standard 1V/Oct scaling found on most synths) needed
play chromatic pitches via external cv sequencers etc using Osc1/2.
Toggle switches on all 3 CV channels allow either a 1V/Oct scale
of 0.32V/Oct scale range to be used. See the userguide for more
As an exampe of how this unit can be used:-
You could have an external sequencer send pitch sequences via CV3 controlling eg Osc1 via row 16 of the matrix. Another sequencer could send pitch to CV2 which could eg control Osc2 via input ch2 and finally still have keyboard control of the keyboard oscillator via Input ch1 with/without possibility of external processing of this Osc. The triggering of the Envelope Shaper could either be by an extenral gate or the DK1/2 keyboard. The other feature on the unit is the ability to invert (or not) CV3. The reason why I added the invert possibility is because the VCS3 and SynthiA(KS) all require negative pich voltages to control osc frquencies via Input ch1/2. This is because these channels actually INVERT any signal passed into them.
The ability to still be able to play the DK1/2 keyboard and have at the same time external pitch sequences to the VCS3 oscillators means that with this unit, the VCS3 mkII can operate a bit like the Synthi AKS where you could have a sequence running on one oscillator and at the same time play accompanying notes from the the AKS keyboard via another oscillator.
The power for the unit is taken from the VCS3 via the Jones socket and is very minimal since its just a few milli amps that are needed for the opamp voltage inverter.
Please note a special version is available for use with a VCS3(mk1) because the mk1 does not have the feature that row 16 of the matrix can double as joystick vertical control or an input via jones plug pin8. The VCS3 mk2 (and synthi AKS) have this feature. So for the VCS3(mk1) a speclal pin cable has been designed to carry CV3 to the matrix. See the userguide for more details.
Here is a demo using an external hardware sequencer connected
to my VCS3(mk2)
via the cv unit:-