Help identifiying Supro - and troubleshoot

[paggerman]

Hi guys. As a break from building daft amps out of old junk, I am trying to help my neighbour out. He has this little Supro (5Y3GT, 6SJ7 and 6V6GT) that has gone a bit wrong. It just makes a big farting noise. I have traced the circuit (attached here) and have taken some photos (will be added soon). First, can anyone identify it? Second, any tips on eliminating the big farts? I have previously added a 3 prong cord and removed a capacitor that was between the fuse holder and chassis - the 'death cap'.

Many thanks for your help

Paggerman

[Prairie Dawg]

I'd start by installing new electrolytics.

[paggerman]

Always the caps

That's always the first answer isn't it? From what I can tell from the speaker serial number this is a 1955 unit. 57 years, I suppose, is well past the life expectancy of an electrolytic - even a hardy Mallory can. I'll pop some new caps in next time I have a need for a fume fix.


Btw, any recognition of the amp model from the circuit? I have gone through all the Supro circuits on Schematic Heaven and there are no matches.

Very many thanks

[Resonator Guy]

A picture of the actual amp would help more in identifying it. The circuit looks remarkably similar to a 57 Supro Super model 1606 that I have. Great little amp.

[Prairie Dawg]

That's always the first answer isn't it? From what I can tell from the speaker serial number this is a 1955 unit. 57 years, I suppose, is well past the life expectancy of an electrolytic - even a hardy Mallory can. I'll pop some new caps in next time I have a need for a fume fix.


Btw, any recognition of the amp model from the circuit? I have gone through all the Supro circuits on Schematic Heaven and there are no matches.

Very many thanks

Pretty much. The original can is about 45 years overdue for replacement specially if the amp has been sitting any length of time.

[riz]

Make sure the speaker is good.

[paggerman]

Amp fixed - just need ID

Thanks everybody. I have replaced the electrolytics and scrubbed the switching jack with contact cleaner and all appears to be good.

All I need now is an identification - just so that my neighbour knows. Here are the pics...

Very many thanks to everyone.

[Jazz P Bass]

All that I could find.
Link: 1957 Supro/Valco Amplifier Blue > Amps & Preamps - Olivia's Vintage | Gbase.com
Supro had more amplifier models than Cambell's has soups.

[paggerman]

Thank you Jazz P

All that I could find.
Link: 1957 Supro/Valco Amplifier Blue > Amps & Preamps - Olivia's Vintage | Gbase.com
Supro had more amplifier models than Cambell's has soups.

That's certainly the same one. Right down to the death cap that is still present. Ah well, sometimes not knowing doesn't matter. I have the circuit diagram traced - and I have a 10w Ss practice amp that needs to be repurposed....

Thanks