Hi Brach, happy Easter!
Well, I’ve gone through the trouble shooting guide again. All voltages are correct. In step 7, I have confirmed orientation and connections for all of the components. I don’t seem to be able to get any effect from the harmonic mix. I have followed the guide to test both but I hear no difference. I was getting distortion when the bypass was off but that was resolved by adjusting the gain trim pot.
I re-flowed all solder joints and re-tested values on many components. Mainly resistors. I did get a voltage reading on pin 5 of U2 of 2.2V instead of 4.5V. I’m not sure where to go from here…
Alex