Category: Modules

SK109-Scale-bias

This module scales the input signal (gain from 0 ~ 1.2) and applies a bias to it (shift it up or down). It works from DC to video frequencies on both the signal and the CV inputs.

It allow s for nice stuff like signal multiplication, luma keys etc.. but is also very handy to get CV-signals into a more useful range.
Note: For better gain lift R215 from ground and connect to negative base of gain pot.

Note: Pushing R307 to 220 Ohms and R308 to 1k8 seems to remove some tendency to oscillate

Note: A negative biased video signal will pull down other channels on the mixer! We should probably add the possibility to clip the output signal between 0 and 1.4V volts, like it’s done on the original sk09-scalebias module.

Parts placement

sk109-place