Power Supply Module Overview
So far for this project, I have been using a charge pump for bi-polar power, I wanted to try and build something a little bit more robust. I hunted through my parts stash, and found a 12v positive linear regulator, a -12v linear regulator to match, and 230v transformer with two independent 12v outputs. It seems like I have the majority of the parts I need to hand so lets get building!
Developing the Circuit
I started off by wiring up the transformer and doing all the mechanical work on an old hammond enclosure. Sorry to my neighbors for dremeling at 9pm! With the hardware mounted, I could test my transformer, and it was working fine, 17v on each output. Perfect for regulating down to my required voltage. I wanted to idiot check my idea and just make sure it matched a suggested way to do this, and I found this circuit:
This was pretty much exactly how I thought I could approach this circuit, so it was nice to see it confirmed. This was the basis for the following layout.
Modifying the VCF
To simplify the drum module, I want to get rid of the voltage controlled section and just leave manual controls. This is the first second draft layout for the simplified drum filter. This module is Lowpass only, I plan to introduce a Highpass only version once this board is tested.