Wally, when I saw that BillM video years ago, it seemed contrary to all the dire warnings we see everywhere. It's a longish vid, but you can scrub to the point where he uses a snubber (about 1:30) and compare to the part where he just switches off the hot amp (about 3:00). But then rewind back to about 0:50 where he just switches on the amp briefly and lets it drain without hot tubes. Bill's point was we wouldn't *necessarily* have to drain 'em if we always started with a hot amp, tubes in place, etc. IMHO, we worry about draining 'em due to the three factors in my post above -- all a risk to amp builders and testers. Other scenarios (filters connected, tubes or heaters not working right) must also exist... I believed Bill's idea, and I tested his idea, but I still drain caps with a snubber, and nowadays put bleeder resistors in amps I build, and even then drain 'em anyway.