I built this 12 months ago. Built with the values on the PCB, Used 1N4148 clipping diodes.
It uses a L78L33ACZ 3.3V Regulator where the Transistor is marked, available now from PedalPCB -
https://www.pedalpcb.com/product/l78l33acz/
I used this part back when - LP2950CZ-3.3
Used 25mm Wide x 6mm Thick very soft adhesive back foam between Nu Tube & Adapter Board, underside Adapter Board & Enclosure back plate to prevent Microphonics and hold Nu Tube in place.
NOTE : Nu Tube tangs need careful attention as they are a little flimsy.
Pictures & comments on Build Reports -
https://forum.pedalpcb.com/threads/nudrive.37/
Great Sounding Pedal!