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the issue you are having still seems odd, since you get the noise when a metal flat surface is simply held over the PCB even without the lid touching the case. right? any change in the noise when the lid is held over the PCB compared to when the lid makes contact with the case? and compared...

FYI -- the components list for the Lab Rat build document do not list the LM308. Easily seen in the schematic, but likely something worth updating.

Shouldn't Fig go second?

I put the new board together and had to troubleshoot it for a while before I discovered that it was using a bad inductor I had gotten from Tayda. Swapped out the part and everything came to life as expected. At that point I had the A1M pot installed for the Bass, but I removed it and used a...

glad you got it working.

have you confirmed the pot values for the 3 tone controls are correct? check them with your meter even if the labels are right. the resistance values for the three of them could be a factor if they were swapped into the wrong places.

I can certainly see why you are frustrated that the tone controls are not working.

Have you confirmed your mid pot terminal connects to ground?

It looks like a break where R11 goes in the circuit might explain the behavior you are having. May be worth another look to make sure the resistor is good even if you have continuity to each end of it.

After testing the board with the tubes in the sockets with audio, everything is OK. With the trimmer on the board there is a wide range of possible voltages for the tubes. They seem OK running with about 160 volts when powered on, which as Nathan noted is a bit lower than the voltages tested...

Thanks for asking those questions. It sent me back to "think outside the sushibox. No problem with the power supply, but I did isolate the problem to my small test rig, although I am puzzled still. I was plugging the PCB into a small testing rig I use with in/out/power jack/footswitch and...

Oooh la la! Lovely build.

I put the 2n3904 in the correct orientation. no change in the voltage drop going into the pedal. also swapped in a new transistor just in case the other had been damaged. still no change. the odd thing seems to be that the voltage boost through the pcb still works as intended, except that...

I love the iterations of the last two steps.

Thanks. It was just replaced with a socket so easily switched or replaced. Only put in the socket to simplify trouble shooting, and the first one was oriented correctly. Still, hope springs eternal. : ^ )

The art work is particularly fun on this pedal, including the panda tail on the front of the box!

Sorry to report that bypassing the diode did not stop the voltage drop on the power. More sleuthing ahead.

Thanks for the suggestion. Will check it out.

Also, the trim pot replaces the 560 R and 4K7 resistors, with the middle leg connecting to the middle leg of the transistor and each of the other legs to the 220K resistor and to ground, respectively.