I built a deathclaw delay and found out, that it is a little bit louder in true bypass than when the effect is active. just before I start modifying my PCB - can anybody confirm, that I can INCREASE the volume of the effect by increasing R5 (currently 15k, I would try 18k, 22k or 27k or even a trim pot).
That's exactly right. Increase R5 to 20k or 22k will probably do it. Honestly, I think all circuits are better with a volume output to account for different pickup types and outputs but in this case there just wasn't room on the PCB to include one.
Thanks to the master himself ;-)