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;

DIY mini Volca Mixer Development

Brief

Make a small mixer for use with things like the Korg Volcas and other tiny synths.  I wanted something I could just grab and use on the sofa with minimal hassle setting up.  Ideally it should contain;

Spec

A compact mixer with between 3 to 6 inputs
Fits in a 1590BB guitar pedal enclosure
Possible Effects section
Not be too expensive

Keep reading to see the prototypes...