VCVS: Voltage-controlled voltage source (4HP)
3 in stock.
"What", you're probably thinking, "is a voltage-controlled voltage source?"
I shall endeavour to explain.
A normal voltage source will generally either output a constant voltage or be controllable via a pot - so far, so boring. This module takes this a step further by making an output voltage modifiable either via a pot or an incoming CV. Furthermore, even though the voltage pot on the module is linear, the resulting output doesn't have to be.
For added fun, the output response is also voltage controllable, and an LED on the front panel will show which response is currently in use.
The supplied firmware has six distinct response curves built in. These are:
- Reverse linear
- Reverse log
The module reads the input voltage (0-5V), looks up the corresponding value in the currently selected response table, and outputs it via an external DAC. Depending on the position of the jumper and switch, the output voltage will be 0-5v or 0-10v - it is not possible to output negative voltages, but running the output through something like the BIAS module will solve that for you.
The two output settings are:
- 0-5V output: SW1 down, R3 jumpered
- 0-10V output: SW1 up, R16 jumpered
I've found that that this module works very well on the outputs from things like envelope generators and LFOs - whilst it could be used for audio-rate signals, the response tends to be very choppy and quantised (this is something I'm actively addressing ...)
You can get very interesting results by feeding the output into a VCF or similar.
The module is supplied pre-built, complete with an Arduino Nano clone with the stock firmware pre-installed. The firmware is available under a permissive license so you can hack on it should you feel the need to - you can get the source from here: https://github.com/yorkmodular/vcvs
Pull requests/additions to the firmware are positively encouraged.
As this is a microcontroller-based module, it will only 'accept' input voltages between 0V and 5V - larger voltages can be tolerated (within reason) but will be clipped at 5V. Similarly, any negative voltages will be rejected and treated as 0V.