In Search of OT for 60's SANO Guitar Amp

[zozoe]

Put the 5Y3 back in and I bet the amp works again!

You also need to note that the filaments in a 5U4 need 1 more amp of current over the 5Y3.
I doubt the amps power transformer has anywhere near that extra current to dispense.

In a way your lucky if it turns out that the 5U4 was bad because if it worked you would have burned up the amps power transformer or in the least blown the mains fuse, or perhaps both.

Hiya SteveM,,, Thanks for all your ongoing support, knowledge, thoughts, & patience!! I'll follow your lead to see if I get anything out of the amp, which BTW sounded killer.... Before I attempt to coax any pleasurable noises out of it,, after 'the incident', the 7591's & getting the 5Y3 back in, things got really hot & very quickly... Does that info point us anywhere, before getting it back on the bench?

Just to recap (no puns) I had the amp for about a week, & as mentioned, it 'was' a killer until the ill-fated recto swap
What's still baffling to me is what was the source if that brief, momentary puff of smoke.... Do OTs actually smoke when toasted? No components looking charred or burst, not that that's the only way of uncovering any failure.... In agreement that I need to get out of my own way with all the tinkering.... Most folks roll tubes,,, I roll amps!! Thnx, Kenny ॐ

[solderhead]

Thnx, but unfortunately there are no known schematics for much of the Sano roster......

Maybe you don't realize it, but you're being deliberately obtuse. Multiple people have tried to help you but you've found reasons to ignore all of the advice you've been given so far, and you've refused to answer their questions.

You've already posted a schematic that shows a basic push-pull configuration. If that is representative of the topology of your push-pull amp then you can write the voltages on that. Change the name of the rectifier tube if you want to. Or if you don't want to write on a schematic, just write down the voltages in a table.

It would help if you could provide a table of B+ voltages and a table of pin voltages at the sockets for the rectifier and power tubes.

Without data, nobody can help you. Many experienced people have tried to help you but none of them are clairvoyant.