Solarus schematics

[Amp Kat]

Ok fellows I'm back on this sunn after putting the new trannys in it and fired it up it works but I have a bunch of hum so I'm suspecting something is wired wrong somewheres. I noticed the schematic I have is not for the Solarus but must be for the Senta because on this amp(Solarus) pin 2 and 9 are tired together on the 6AN8 or 7199 and the schematic I have doesn't show that. Man this thing sounds awesome and I want to keep the existing PI as the tone is really nice and unique. I scoped it out and the plate side of the PI is fine with good signal but the Cathode side is small and square and I'm thinking that's where the hum is coming from. Anyone have a Solarus schemo ?

[Enzo]

At least one drawing has that connection left off the drawing. The only thing connected to the plate of the tube is a cap in that drawing. Obviously a mistake. The 7199s are all direct coupled pins 2 to 9. The 6AN8 has pin 2 to 6. The drawings don't show a ground connection for the preamp tube cathode resistors, but they do go to ground. Are you looking at 100S?

All the Sunns of that era pretty much used the same circuit. The 7199 phase splitter went with the EL34 output tubes, and the 6AN8 splitter went with the KT88s. Other than that, they were all really really really similar.

I'll send you the SOlarus I have. But with darn few exceptions, most any SUnn schemo with the same outputs and phase splitter tube complement will be close.

Got hum? Isolate it. Pull the preamp tube. Stull there? Pull the phase splitter. Tone controls affect the hum? Remember the reverb return is a transistor, as is the trem drive. They have a separate power supply, +16.5VDC - voltage D on the drawing. IF that is hummy, either of those effects could introduce it to the signal. That is half wave too, so the hum would be 60Hz, not 120Hz. And don't forget the bias supply also has its own filter caps.

[Amp Kat]

Got hum? Isolate it. Pull the preamp tube. Stull there? Pull the phase splitter. Tone controls affect the hum? Remember the reverb return is a transistor, as is the trem drive. They have a separate power supply, +16.5VDC - voltage D on the drawing. IF that is hummy, either of those effects could introduce it to the signal. That is half wave too, so the hum would be 60Hz, not 120Hz. And don't forget the bias supply also has its own filter caps.

You know I was kinda confused on that schematic as D is also going to the first preamp plate voltage which surely can't be +16 volts. I'm thinking the last voltage off the plate supply with the dropping resistors is for that ?
I will check that +16 coming off that board and I did rebuild it with all new e-caps and hoping that tremelo box is good. Post back tomorrow. Have to think you onto something with the pots because if I pull the 7199 hum is gone.