Gordon has done a great service here, if it hasn't been mentioned tons of times before with eight pages of replies. I just have done my work on one Heathkit AA-100. Indeed those anode resistors were at 880K and 950K, replaced and done, as well as the four 220K replacements on the 7591's. Recapped the entirety, including filter cans (why are they insulated from chassis ground?). With a ton of dust, got this one working. I was really unsatisfied that on another AA-50/AA-100 that I couldn't repair the selector switch as the solder just wouldn't take. It confused me at first, but now working at an electronics shop it was suggested that it must have been made using plumber's solder or something. Grabbed a new unit, followed Gordon's procedure and check process, and am listening to an excellent amp as we speak (luckily I could solder this one because the correct solder was used). This advice is a goldmine. Thank you for the advice Gordon! The 12AX7 swap for 12AT7 I'm still playing with--not sure which I like better at this point but will post once I do. The input tubes V-5 and V-6 really react to the character of the amp much more than I've ever seen with tube-rolling. Sound best right night with Bugle Boy 12AX7s, but Tele's 12AT7's are close as well. Cheers and Thank you Gordon for your advice. And yes, I'll get better output tubes later than JJ's.