Got a question about Q5,Q6 and VR1.
From post #9:
"Torque is probably too strong a word, though, because you want to tighten them so that the lock washer is obviously compressed, but not enough so that the thermal pads get cut. There is high-voltage going through the CCS transistors, so you don't want them shorting to the heat sink."
The MJE350 and NJM2396F63 looks like they isolated, in which case thermal pad or paste requires only for better heat transfer not isolation from heat sink. Just want to be sure. Thanks
Back then, there was the possibility that other transistors could be used. In fact, the LM317 was used during the first prototyping. Also, there are many versions of the MJE's that have metal backs. However, since Dsavitsk standardized on only isolated (all plastic) transistors and VR, you are correct.