DIY Volca Mixer Prototype

This has taken FAR longer than expected to complete, but finally the prototype of the Volca Mixer is ready.  I've settled on the following features;

3 Inputs
Aux effects send/return, with each channel having an amount pot, plus an overall amount pot
Switchable Global Delay
Switchable Headphone Amp
The mixer has the ability to run without batteries (bypassing Delay and Amp)

Here's a quick video of it in action;

Keep reading for full schematic;





The next step is to now design a PCB and see if we can get it all to fit inside a guitar pedal like this one;

If you'd like to build this mixer, here is the schematic (German readers may spot the 'amusing' name of the unit);

;-)