Tone bender problem: signal vanishes

[the monroe transfer]

Hi all; been away for a long time and, as a result, the little I knew has now vanished from my brain.  I'm building a Coloursound Tone Bender, using Lowstar's layout as below...


Of course, it didn't work first time.  Using my little audio probe, I've found that the signal goes into C5 and R6 fine, nothing comes out the other end.  I think I can eliminate dry joints and wrong component values; does anyone have any suggestions...?

Thanks for reading.

nick

[PRR]

Track cut under R13?