After a few hours of operation, I decided that it was time for a real look under the covers
A procedure which is much easier said than done, as there are lots of 4-40 screws to remove, and some of those took a bit of patience and perseverance to remove. Just think of those vexingly complicated 1950's and 1960's vintage wooden "Chinese" puzzles which were fairly challenging to take apart, and then put back together again.
First of all, I should have known that it has no SRPP circuitry at all, it is clearly stated that this is a non-inverting circuit, and SRPPs invert.
The topology is a common cathode 6N1P VA stage (not to be confused with grounded cathode), and a 6N6P White cathode follower. For those who have Tube-CAD, the VA is hum-bucking common cathode "D" , directly coupled to a White CF "A"
Each VA stage consumes about 8 mA, and each WCF output stage consumes about 28 mA, for a total of about 76 mA for both channels, at 212VDC.
The power supply uses two separate MCI brand PC mounted transformers (made in California) , one for the 212 VDC B+, the other for the filaments' 6.3VAC.
Most resistors are Dale, 1% 1/2 watt, some 1 watters are used where needed. The power supply has a total of nearly 2,000 uF of capacitors, and this unit is dead quiet, no hum, ripple, buzz or noise. The volume control is 100K stereo Alps "Blue Velvet" Caps are a mix of Nichicon electrolytics and Wima MKS4.
I'll post more specific details later, right now I have five pencil- scribbled sheets with schematics, parts values, component designations, voltage measurements, commentary, notes, etc, which currently more resemble ancient Egyptian heiroglyphics than any true technical documentation.
I even toook a few photos of the board, which is very neatly and cleanly designed. Everything is PC board mounted, there are no wires or cables.
The best part is, I got it all reassembled, with no missing or extra parts left over, and it still works
/ed B