135 Watt Silverface Twin Reverb Fuse, 4 or 5 Amp?

Injam

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Hello,
I got a 1977 Fender Twin Reverb recently. On the back panel where the fuse is located it states: 4 amp slo-blo. When I looked at the fuse that was installed it was a 5 amp. Next I downloaded the wiring diagram to verify the back panel. But the wiring diagram says to use a 5 amp slo-blo fuse. Do I have a super rare vintage amplifier with a mistake on the back panel?
9C4B1FF5-0956-4CED-B31A-79FAC2E372E0.jpeg
 

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dsutton24

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Unless I've completely lost my faculties altogether, it looks to me like the schematic you posted says 4 amps. That's where I would start anyway.
 

rdjones

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I have a Bassman 135.
For the most part it is the same circuit minus the reverb and tremolo.
The schematic shows "4 AMP" and the panel calls for 4 Amp.
It has a 4A fuse installed.

The schematic you posted calls for a 4A fuse in the US 120V version.

Are you blowing fuses ?
If not, I'd install the correct 4A fuse.
 

Injam

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Unless I've completely lost my faculties altogether, it looks to me like the schematic you posted says 4 amps. That's where I would start anyway.
You are correct. I was confusing the symbols for the plug. Thanks
 

Milspec

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If you are blowing fuses, suspect rectifier diode failures. For some reason every SF Twin I have seem to have cheap diodes installed that needed replacement.
 




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