Selenium rectifiers

[atmars]

I have some selenium rectifiers in and old amp. I have read these can be replaced with solid state silicon diode rectifiers. Is this accurate? Would it just be a simple swap? I have also read that each fin represents twenty watts. Any suggestions on how to determine the correct rating if this swap is possible?

I have some strange voltages and I am not sure these rectifiers are doing their job. Also, they take up a lot of space, so i have some reasons for replacement.

Thanks

[Steve Conner]

Yes, it's a simple swap. 1N5408 diodes should work fine unless your amp runs some crazy 1000V B+ with transmitting tubes or something.

I don't know where you heard 20 watts per fin, but it's almost certainly wrong. If anything, it's 50 volts per fin or something like that.

Selenium rectifiers should be replaced whether they're working or not. If they ever decide to blow out, they'll stink your house out with evil-smelling toxic fumes.

[Bruce / Mission Amps]

Yes, it's a simple swap. 1N5408 diodes should work fine unless your amp runs some crazy 1000V B+ with transmitting tubes or something.

I don't know where you heard 20 watts per fin, but it's almost certainly wrong. If anything, it's 50 volts per fin or something like that.

Selenium rectifiers should be replaced whether they're working or not. If they ever decide to blow out, they'll stink your house out with evil-smelling toxic fumes.

I think SS diodes will also be more efficient and give you a higher B+ so watch for old filter caps to be potentially over voltaged.
If high B+ is an issue, (I doubt that if your amp has Se diodes) just run two cheap 1N4007s in series to get some extra breakdown protection.

[atmars]

Thanks all,

I don't know where you heard 20 watts per fin,

I read 20v per fin. Sorry, I was typing, not thinking.

[Enzo]

Once you smell a burning selenium rectifier, you will NEVER forget the aroma. it makes me think of rotten cabbage on fire.

I was at a guy's house not all that long ago and he asked me to look at his old console Telefunken radio. Open fuse. STuck a new one in there, and FEEEEW!!! Out came the stinky smoke. It had probably been 30 years, but I instantly knew what it was - blown selenium rectifier.

[Gtr_tech]

We used to blow up Se rectos back in high school just to stink up the room. We didn't know the smoke was toxic......

[Enzo]

Right, like in chemistry class where we'd coat dimes with mercury to make them shiny, then carry them around in our pocket.