If your still working on this issue I have solved my really low output issues. The lone king I put electrolytic capacitors in the PCB instead of tantalums and I'm pretty sure I put in 22uf instead of 220nf which stifled the output.
On the other pedal I put a 470nf instead of the 470pf it was supposed to be. Silly mistakes, not reading the documents close enough and the silk screens were a little misleading in that they had a picture of an electrolytic and the big box you see around the bigger caps. I'm just an idiot. Good luck, re check your capacitor values.