Module is available as a DIY project only.
This Module is currently available.
Dual discrete-transistor VCA / Lowpass Amplifier
The Slightly Nasty Model 1221 Discrete Lowpass Amplifier is a dual discrete-transistor VCA that offers the choice of either traditional VCA operation, or “Lowpass Amplifier” mode – where the amplifier also lowpasses the signal with cutoff frequency tied to the signal gain. This is accomplished by adding a 12dB/oct transistor-ladder filter stage to the top of a classic differential-pair VCA circuit, creating a circuit that varies both amplitude and bandwidth of the signal with a single control current.
The Level input features both an attenuverter and a variable response curve which is continuously adjustable between linear and exponential. The signal Input has a level control that allows for greater-than-unity input, to allow the discrete VCA core to be overdriven and take advantage of the inherently smooth distortion characteristic of this type of circuit.
A large Bias knob is provided to manually open the VCA, allowing for manual performance, or reverse operation in conjuction with the CV attenuverter when doing things like sidechaining or compression effects, among others.
The Lowpass Amplifier mode is great for mimicking the natural effects of distance on a sound, where the high-frequency content fades with distance more quickly than the lows. It can also add a slightly more organic quality to sounds, making their harmonic complexity increase in intensity as they get louder. Another use case is creating simple synth parts without tying up a dedicated VCF module – great for adding little extra elements to a patch.
https://www.slightlynasty.com/model-1221-discrete-lowpass-amplifier/
