Finally got around to this one today - fun, easy build! Didn’t take more than half an hour.
Makes me wonder - if I wanted to build a stereo version of this, could I duplicate it and send the input of a channel to both subcircuits directly and send the outputs to the left/right channels of a stereo pot, or would I need to add an extra TL at the beginning to boost the levels?
You’re well on your way to reinventing the Barton Stereo Outs! They use a buffer before the signal split but not to boost the levels, the gain is 1; it’s to buffer and invert the signal so after the inverting mixing stage the output is in phase with the input. Why they didn’t re-invert it at the two outputs instead of at the four inputs I don’t know. In Sam’s design there is a second inverting stage after the mixing stage. So no added op amp up front needed unless you want to buffer the inputs, which would be probably good but not necessary.
You’d probably want panning pots on each input, similar to the Barton circuit.
That was really interesting! Thank you so much this deserves more likes
Hey guys. So i just finished the SSO. I am a complete beginner.
I would like to link 3x SSO into this Super Simple Mixer. How would i got about that?
Since the SSO has wires to a DC, Tone Filter, and a Jack output.
Im not sure how i am supposed to link the Jack output to the Input of the Mixer? As i want to skip the extra Jack Output. Could the Hook up Cables to the Jack output be soldered directly into the input of the mixer?
Could someone explain it with a simple Drawing?
Welcome to the forum 
yes as you said, simply remove the jack sockets and directly connect the + to the + and the GND to the GND.