Built this one, and had the very low output issue that someone else had - almost no output.
Checked pots, all component values, replaced a couple of resistors for good measure.
Knifed strips, checked continuity, everything seems okay.
Tried different transistors, tried JRC4558, RC4558P, TL072, no luck.
Pulled ICs and Transistors from working builds that I know worked, still low output.
Where you have made cuts by drilling holes just check that the strip is completely cut. I had a thin slither of copper still attached which drove me mad until I eventually spotted it!! Looking at the pic of the underside of your board going from top left check 7 across 4 down!
Check the CUT in the bot line. These veros has connections under the paint in the top and bot lines
Thanks - that was the culprit. I've gotten in the habit of using my meter on the continuity setting to check that all my cuts are complete before I start soldering, but I must have missed that one. Sliced the track with an Xacto, reflowed a few joints and I have tube-screamery goodness!