The New Systems Instruments VCA module gives you four well-calibrated VCAs in 6HP. These VCAs use operational transconductance amplifiers (OTAs) at their core, for true linear operation. However, unlike most OTA VCAs, the New Systems VCA is extremely low noise and distortion, coming in at < 0.2%, with ~0.05% typical.
There’s no such thing as “transparent,” particularly in synthesis, where the concept of an original signal that could be faithfully reproduced is often altogether absent. In a VCA in particular, a desirable envelope response can be even more important than accurate reproduction of the input at some fixed level.
The New Systems Instruments VCA has an extremely neutral, open sound. The envelope response sounds pin-pointedly fast and accurate. If you want a dirtier VCA, stay tuned. We’re in the process of designing a different VCA with some control over signal and envelope linearity.
The VCA can be used equally well to control the level of audio or CV signals. For example, you might want to use a stepped random voltage to control the intensity of a filter envelope’s sweep. You would patch the envelope’s output into the (signal) IN of the VCA, and patch the random voltage’s output into the VCA’s CV input to control its level. Finally, you would patch the VCA’s output into your filter’s CV input. You would then hear a different intensity of filter sweep on each step of the random voltage generator. Many more variations on this theme are obviously possible.
- THD+N at 1kHz: 0.2% (max), ~0.05% (typical)
- Output Swing: −10V–+10V peak
- Input Range: −10V–+10V peak
- CV Unity: 5V
- Input Impedance: 85kΩ
- Output Impedance: 150Ω
- Output Drive: 2kΩ (min), 20kΩ+ (ideal)
Power: 25mA @ +12V / 25mA @ -12V