• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Out Of Order

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hi,
My tube amp was working well until I plugged in a defective guitar booster.
my trafos give me 220v as before but after bridge rectifying i get 680v AC!!!!!
I don't get it, i am just a DIYer not a tech. Can somebody help? I have bought another bridge but i must now what has happened - safety reasons.
Also as i had 400v max. caps and they went up to 600v and more,
should i change them all?
I fear for my OT's.
Thanks
 
You probably lost your rectifiers and possibly the filter capacitors.

:att'n:If you're not experienced with high voltage work, DON'T MESS AROUND WITH IT, let a competent tech do the work. Electrocution and explosions are entirely possible.:att'n:

The good news is that your OPTs are probably OK.
 
Ex-Moderator
Joined 2003
Right out of order

alk said:
Also as I had 400V max. caps and they went up to 600V and more, should I change them all?

Yes, you should. You have stressed them. They might not blow up immediately, but their lifetime has been drastically shortened. They need to be replaced. Find an experienced person to fix it...

("Right out of order" = "You shouldn't have done that.")
 
I've installed a new bridge and still no DC coming out. I get 440v AC in my multimeter. How this can happen? I'm lost, my multimeter works well in other readings. What the hell is going on?
How a 230v trafo can give 440v AC after rectifying is a complete mistery to me.
 
Hi,
yeah i suspected the multimeter went wrong. I've done some testing to find out it doesn't read DC anymore, now all is AC. Having said that, my problems are not resolved. Now i have 440 v
DC where it should be 280v. Volts readings are ok. It reads my house 230v accurately and i tried with a dc transformer that i got and it reads 12v well but instead of dc gives ac which is what is wrong with my multimeter.
So give the high voltage ? It is a 230v trafo.
 
Proof.
 

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