Tube Amp Archive

Thanks Mike - I will take a look at that. Having spent so much time nosing around inside her I'm eager to do a few tweaks again, so this will be on my list
Cheers
Phil

Ha! Yes, reading back through I had all the answers. It's rather easier in "hindsight mode".... ;) So pleased she's back though - I've borrowed a solid state Fender combo to get through the last bunch of gigs and oh my, it's fine for clean but overdrive is a different matter. When you put pedals in ...

Well see's been quiet since I swapped the mica so I guess that was it. Many, many thanks to all for the help, especially Martin - I was genuinely at the end of my tether this morning over the amp and now she is back. Thank you! I guess the good news is the amp won't need new caps for quite some time...

I'll say!!!!! Have swapped the mica cap out for another and so far so good. Will give her an hour sitting there quietly - if no more noise then we have a winner!

Reel - just the power tubes flash in the dark.

Martin - many thanks, just grounded the wiper of the treble pot and the noise stops (in fact all sound stops!) When I pull the clip the sound returns. Will swap out the cap right now

Steve - when I lift the plate resistor on V2 the noise stops. Still there with V1A and V1B.
I've replaced the tube socket and the plate resistor with new. When I tap the caps and resistors upstream I get no noises - is it worth replacing the caps in the tone circuit?
Cheers
Phil

I've replaced the plate resistors already - that's the 100k on pins 1+6, yes?

I reflowed all the solder joints on the board and also went through the sockets - instant I turned the amp on there was the noise :( So - I am totally at my wits end. I have replaced most of the components except for the trannies or choke. The noise stops if I pull V2 or the PI tubes - has no-one ev...

Have videoed the amp making the noise - hope this sounds familiar to someone? A friend suggested I remove the grid wire from V2 to see if it had an effect - it didn't, the noise still appeared. He suggested I probe with a cap to ground at the cathode and plate to see if it helped - again, it didn't....

Yeah, a bunch of trusted ones - still no change.

I unsoldered the wire to pin 2 (the grid, right?) of V2 and still the amp would make the noise after it warmed up. I pull V2 and it stops - what should I be looking for next? I gotta be close
Cheers
Phil

Yes, normal Fender 6V heaters. Just checked and the voltage is steady, even when making the noise. So that's a good thing, yes?

Latest update.... Have replaced all the electrolytics in the amp with new and replaced the tube socket at V2. No change...still the same noises blue flashes from the power tubes :( All the voltages seem fine - as I have previously said, I've been gigging the amp for over a year so its not like she's...

Pin 1, 7 and 8 I get 180V, 334v on pin 6. I've swapped half a dozen tubes in there with no change.

If I wiggle the tube it doesn't make a noise - I'm thinking it may be an electro on the way out. I have new caps and a new socket on their way - hopefully with these parts swapped out it should be resolved. Hopefully!