Quad Voltage Controlled Amplifier

From MMM Wiki

Jump to: navigation, search

Quad VCA

The Quad VCA is designed as a utility module for providing four basic VCA's to be grabbed for a patch.

Each of the four identical VCA's include:

Audio/CV In Channel input: The VCA's are DC coupled to allow for signal processing of CV or audio signals.

Control in CV input: The amplifier stage responds to a 0 to 5V control voltage.

         5V for full output. 0V for fully attenuated.
         All of the CV inputs are cascaded. 

The CV applied to channel 1 will control all four VCA's. Inserting a CV into another CV input will interrupt the cascade and apply the new CV to the selected and subsequent channels.

Level control: Allows for adjusting the gain stage of the channel from 0 to unity gain. On-board trimmer potentiometers allows for the user to adjust the maximum output gain for each channel up to just below the power supply limits providing up to a 2.5 gain amplification of the input signal.

Or, there's a trimmer for setting the cascade voltage for when there is no CV plugged into the CV input jack. This can be adjusted for setting a "normalized" amplified gain while an external CV will interrupt that and provide a 1:1 setting. It depends on the intentions of the owner. You can adjust them for your specific applications.

Channel output: Output jack for the channel.


This module is available $250.00

Assembled/ tested board only: $110.00


Current draw:

V+= 35 mA

V-= 35 mA

PCB board dimensions:

3.125" (3-1/8") 79.38mm X 2.625" (2-5/8") 66.68mm

Mounting holes: 0.125" (1/8") 3.18mm (for 4-40 screw) 4 holes, one in each corner

Mounting hole spacing; Length: C-C= 2.925" 74.3mm, Width: C-C= 2.425" 61.6mm

Personal tools