Seventh Circle Audio

When adjusting the R39 to get 21.04 volts, how much do you have to turn the screw before something happens?

First, read through the sticky at the top of the N72 forum. The voltage you should be adjust for is 22.6V, not 21.4V. To answer your question, it takes several turns before anything starts happening. Connect your meter to the C of Q6 and watch the voltage as you adjust R39.