FWIW the power transformer HV secondary is 260VAC, which is then rectified through a 4-diode FWB, generating B+ of approximately 325VDC.
They were selling the original Japanese R-core power transformers for these amps, at a fairly low price, it has a 100VAC primary, but it will operate very nicely under full rated current load with 120VAC powerline input, and the 6.3VAC filament winding will output 7.5VAC, and the HV winding 312 VAC. I ran it fully loaded for several hours, and the tranny barely got warm.
(I bought four of them, at the time, and posted testing results about these trannies, about 9 months ago).
They are still available:
https://tubedepot.com/products/r-core-2 ... ransformerFWB Rectify the filament and it will deliver close to 8VDC, which would work very nicely with 8BQ5s and 8CG7s, 8FQ7s or 8GU7s, for a nice SE amp, or a single PP monoblock.
PDF file describes this trannie:
https://d1sjrnpi226dnf.cloudfront.net/s ... 1382030195My earlier posting, copied from the
ZeeBee posting of
Fri Apr 26, 2013 3:19 pm viewtopic.php?f=19&t=4999&hilit=877The R-Core power trannie looks similar to the PT-877 which was on sale from Tube Depot a few months ago, which has 6.3VAC @ 3A and 260VAC @ 200 mA
secondaries, and 100VAC primary. (these were intended for use in Japan, where 100VAC is a normal line voltage)
They tested it with 120VAC on the primary, and got 7.56VAC and 312 VAC, loaded at the rated currents.
I bought four of them (they were cheap) and used a tapped autotransformer to test one at 100VAC,
and loaded the 260VAC winding with a 40W, 230V light bulb (about 180 mA at 260VAC), and the 6.3 VAC winding with a 6AS7 filament(2.5A)
the transformer just barely got warm, even after several hours' continuous operation.
I figured, use it on 120VAC with 8BQ5s and 8CG7s (or 8SN7), in a modified Clementine or Budgie SE design. The filament voltage might be a tad(about 5%) low,
but it is still within operating specs for these "series filament" tubes... 8SN7s do exist, though they are not really "common", I have a few "Zenith" branded ones.
Lower gain then the original 12AX7 / ECC83s, but then, that's what preamps or line stages are for