Diode question

[lowbrow]

I have a 75 Fender Bassman Ten (converted to a head) that I've been slowly rehabbing. I've replaced the output transformer, all electrolytics, a few resistors, jacks, power cord, disabled the ground switch, etc.

It's now functioning very well, voltages are good, sounds are fantastic. About the only thing left is I'm considering replacing the diodes (in the rectifier and bias sections).

Is this good preventative maintenance? Are 35 year old diodes prone to be suspect?

I can see nothing on the schematic about what they are exactly, and haven't been able to read any of the markings on them...if I was to replace the, what would you folks recommend I use?

Here's the schematic:

[Albert Kreuzer]

What was wrong with the old output transformer?

Those rectifier and bias diodes are usually fine. They don't seem to die of old age.
But I preventatively (is that a word?) replace any old selenium rectifiers when I find them (e.g. bias diodes in Fender tweed amps).

Cheers,
Albert

[lowbrow]

What was wrong with the old output transformer?

Those rectifier and bias diodes are usually fine. They don't seem to die of old age.
But I preventatively (is that a word?) replace any old selenium rectifiers when I find them (e.g. bias diodes in Fender tweed amps).

Cheers,
Albert

The original was long gone when I got this amp, and the one in it only had one tap ( I suspect 4 ohm) and didn't fit the bolt pattern properly. A new one from Weber was cheap (in my eyes) and fit properly and gave me the 8 ohm tap I wanted.

[Prairie Dawg]

The original was long gone when I got this amp, and the one in it only had one tap ( I suspect 4 ohm) and didn't fit the bolt pattern properly. A new one from Weber was cheap (in my eyes) and fit properly and gave me the 8 ohm tap I wanted.

1N4007s would do just fine but I wouldn't bother myself.

The circuit looks a lot like my Bantam with the exception of the tube rectifier. Right now it's running with a GZ34 and a Twin Reverb output transformer. Through a Jensen 15 inch speaker it sounds compact and muscular. Highly underrated amps and thus available on the cheap until people stop listening to the 'experts' and make up their own minds.

[lowbrow]

1N4007s would do just fine but I wouldn't bother myself.

The circuit looks a lot like my Bantam with the exception of the tube rectifier. Right now it's running with a GZ34 and a Twin Reverb output transformer. Through a Jensen 15 inch speaker it sounds compact and muscular. Highly underrated amps and thus available on the cheap until people stop listening to the 'experts' and make up their own minds.

I had a feeling that would be the recommendation.

I love the sound of this amp. I play guitar in, for lack of a better description, a garage rock band. My main amp is a Silvertone 1484, but this one is gonna see rotation soon. It's got great breakup at reasonable volume and when the channels are jumpered, it's unlike anything I've ever played. It takes pedals very well too. I'm leaving the fixed bias alone because I like the tone now and I figure at around 16 watts per tube, I'll probably not need new tubes in forever!

[Prairie Dawg]

I had a feeling that would be the recommendation.

I love the sound of this amp. I play guitar in, for lack of a better description, a garage rock band. My main amp is a Silvertone 1484, but this one is gonna see rotation soon. It's got great breakup at reasonable volume and when the channels are jumpered, it's unlike anything I've ever played. It takes pedals very well too. I'm leaving the fixed bias alone because I like the tone now and I figure at around 16 watts per tube, I'll probably not need new tubes in forever!

My problem is I'm a sucker for anything with a fifteen inch speaker in it.