by kheper » Tue Nov 13, 2012 9:41 pm
The 70V bias tap will permit the use of KT66s, etc. without rebuilding the bias supply. The 2 x 4A filaments, however, are 2A less than than the PA-060. (4 x KT88 + 2 x 12au7 + 12ax7 = 7.3A filament current) On paper, 8A looks like enough juice, but a surge at start up may stress the transformer. Maybe get a small 6.3V transformer for the driver tubes?