S404 VCA

Product Description

 

(This module is included in the System B)

 

The S404 is composed of two voltage controlled amplifiers that share the same CV and manual amplifier knob. Each VCA has it’s own input/output. Three curves of amplification are selectable with a switch, Linear, Exponential*, Logarithmic**.

 

There is also a mix output of both VCAs. There is a Cross Fade input (XFade) that can be used to morph the mix output between VCA 1 and VCA 2 outputs. When the XFade input is 0V, the Mix is equal to 0.5 x Out1 + 0.5 x Out2. When Xfade is -1V, Mix is equal to Out1 and when Xfade is +1V, Mix is equal to Out2.

 

The S404 clips at +12dbFS. A clipping LED is provided at both VCAs. Notice that clipping can cause distortion and in the worst case, aliasing. It is best practice to patch and tune things in a none clipping manner. Unless of-course you really like the clipping effects and artifacts. To prevent clipping, lower the input levels, or lower the CV input. If you can’t get enough volume/gain without causing the VCA to clip. Then leave it low and amplify the audio latter after the VCA. For example at the output module using the SA02 or SA05.

 

*Exponential is approximated using a polynomial.

*Logarithmic is approximated using a polynomial.