I understand and appreciate the give and take on the capacitor foil orientation issue. I'd never paid attention to it until this 18-watt TMB build. For what it's worth, I decided to mark them and orient them as correctly as I knew how. I fired the amp up for the first time last night and the amp is utterly dead silent when not playing. No hum whatsoever. I also took an effort to heat shrink the leads on all my board components which I also had never done before, as well as used Mogami shielded wire for the signal wires under the board.
Sounds nice, man. I have some fizz to work out potentially, and I'm going to switch out my JJ EL84 for some EH or better tubes. Looking for more bass.
Just plug it in, man.