Hi Ian, I can see you are really enjoying yourself perfecting the sound of the TU-05B. Hearing your impressions on tube rolling really makes me wants to go out and get those tubes Immediately. According to Kageyuki-san, 3S4 and 1U4 are directly heated tubes and it takes few minutes to warm up. I will try my local stores to see if I can find those tubes recommended by you. Enjoy your weekend!
Ooh, thats useful info, thank you! Have a great weekend also, with this amp I think that is assured eh!