IF101 - 2Q/4Q

Two-Quadrant/Four-Quadrant Analogue Multiplier

The IF101 is an analog multipler that can be switched between two-quadrant and four-quadrant operation and so can function as a voltage-controlled amplifier (VCA) or as a ring modulator (RM).

Operation is the same as for any other VCA and RM modules.

As a standard VCA, audio goes in to the [X IN] input and control voltage goes in to the [Y IN] input. The [BIAS] control can give the VCA an "initial gain", useful for AM applications such as tremolo etc.

As a RM, the "carrier" goes in to the [Y IN] input, and may be mixed into the output with the [BIAS] control. At full bias, the output is just the carrier signal with no modulation.

http://elby-designs.com/contents/en-us/p1092_IF101_-_2Q_4Q.html