NGF-E Project: Mix Out (COM) stuffed PCB

This is my replacement of the original Elektor Formant COM module used in my Next Generation Formant project. I discarded the original circuitry because of the TL085 used with his unusual pinout and the availability of dedicated audio operational amplifiers. I used a more effective filter implementation for tone control. A mixer front end with four external inputs is added to make patching easier. A optional level indicator makes it easier to find the right volume level for best SNR. The maximum output volume is adjustable to protect your PA

The documentation for download can be found in my website.

NGF-E Project: Mix Out (COM) schematic

Nothing special in this schematic. The tone control is a Baxandall type.
Calibration procedure and more information on my website.

NGF-E Project: Mix Out (COM) front view

NGF-E Project: Mix Out (COM) back view