trinityamps.com

Hi, hope you can help me. i've just made up a Tweed Deluxe and it sounds great except for way too much hum. I've tried all sorts like swapping the OT primaries around, filaments, repositioning the OT, swapping out all tubes, re-wiring the input jacks, moving cables all around but without success.

These are things i have noticed:

There is no hum when the volume pots are at 0
There is no hum when you pull the V2
You can still hear some hum when you pull V1

I would be grateful to hear from anyone who has had a similar problem and managed to resolve it.

Thanks

I've switched the plate and cathode resistors to metal film. I've rewired the inputs with metal film and shielded cable right to the grid pins and I've upped the first filter cap to 40uf. The hiss did improve but it didn't illiminate it. The "bright" channel is especially hissy.

Are you experiencing hum or hiss?

It's hum. I can induce a sort of hiss if i put my fingers in certain places, but this is hum which gets worse as you turn the volume up. i took the amp apart last night, took the board out and checked everything was correct underneath and it still hums terribly.

Wish I knew more to give you some advice that could help you..you might have to go to another website to get help, because this site has tumble weeds blowing through it..

I managed to fix it a few days ago after trying everything. I was playing it at a friend's house and it started smoking after about 90 mins. I turned it off and popped the back and could see shellac oozing from the power transformer, one of three I had made by Trans-tronic of Chesterfield who make HiWatt and JMI trannies. Turns it it had a filament short. I put another tranny in and the hum was gone.

Thanks for the helpful advice, I'll use it on a Trainwreck Liverpool I built with too much hum.