18Watt.com

Hi all,

I've got a Fender DR style amp which uses a 5Y3GT. A while ago it went pop which I've traced to being a blown PT.

I was using 40uf filtering for the first stage, which it appears reading posts here could have caused the 5Y3 to fail, which I'm guessing could have been what popped the PT.

My question is : how can I test the 5Y3 before I refit a new PT to ensure I don't blow the new one?

I think I'll reduce the first stage filtering to 20uf and fit a HT fuse this time as a safeguard against future mishaps

Well, for the future, you may want to consider using an HV fuse. Not really sure about that rectifier test though.....

Are you sure the PT is gone?
I really don't think 40uf in the first filter position is going to do that.

You can test your amp with a light bulb current limiter before you apply full power. It could save you lots of PT's, fuses and other assorted stuff.