Quadraphonic Toolbox

Components Needed

A 4 channel voltage processor and general utility module. Each channel has an attenuverter, DC offset, and a switch to select 1x gain or 5x gain. All channels are sent to a mixer with positive and negative outputs. Channels 2-4 are normalled to channel 1. 

When it comes to selecting switches - we have used custom mounting holes that allow a wide variety of switches to be used. Tayda part numbers are provided for an example but pretty much any switch with 4.5mm between the pins should fit. If unsure, send us an email sentientsynths@gmail.com - and we'll check for you. 

When building, start with the lowest components first, the resistors, capacitors, ICs and diodes. If you would like perfect unity gain you can install the resistors labeled 47k* and the 100k cermet trimmers and omit the 100k resistors labeled R*. If you do not need perfect unity gain, omit the 47k*s and 100k trimmers, and instead install the 100k resistors labeled R*. Do not install both! Once all SMD components are in place, put the board connecting pin headers in their homes and solder them with both boards in place to ensure correct orientation. Finally, insert the I/O jacks, potentiometers and switches in their respective homes, and install the faceplate while soldering, again to ensure correct orientation.