MFB VCA

MFB VCA is a VCA module for modular synthesizers in Eurorack format. The module is a classic amplifier in Eurorack format with which audio and CV signals can be controlled using control voltages. The Voltage Controlled Amplifier has three inputs. Input 1 can be controlled with an attenuator. Inputs 2 and 3 have no attenuators, but have different sensitivities. They are not used for mixing signals, but rather as alternatives for different signals.

A VCA with tremolo effect

The signal amplification can be controlled via the two CV inputs. CV-1 is normally controlled by an envelope. A special feature of CV-2 is that this input can only be used in conjunction with CV-1. This means that a control with a CV signal only takes place here if a voltage is also present at CV-1. A practical application is volume control with an envelope on the CV-1 and an LFO on the CV-2, so the tremolo is only effective as long as the tone is held. Normally CV inputs on VCAs are connected in parallel and an additional VCA module is required for a tremolo effect. The signal is output via two parallel outputs. Output 1 has a fixed level, output 2 has an attenuator with which the level can be controlled.

MFB VCA at a glance:

• 2 CV inputs with dependency
• logarithmic characteristic curve
• 3 audio inputs and 2 outputs