This is a single-channel VCA based on a THAT2180 chip. It’s ultra clean and sounds fantastic. It’s a perfect sonic companion to the MA MIX and also works well as a final output module.
The VCA has a manual gain control (offset) and two independent CV inputs, both with an exponential (audio) response curve. They are configured to take 0-5V CV signals which will open the VCA fully to unity gain. CV inputs above +5V are diode-limited, a feature which can be exploited to change the effective curve of an envelope signal (similar to a “hold” stage in an AHDSR envelope). The inputs of this VCA is AC-coupled, so consider this one for audio only.
BOM & Build Support Thread – http://www.muffwiggler.com/forum/viewtopic.php?t=101202
Unlike previous revisions this PCB requires no modifications.
Specs:
- Width: 4HP
- Depth: 39mm
- +12V: 10mA
- -12V: 15 mA
- +5V: 0 mA