Trying to Catch TinkerBell

[Blind Lemon]

Been building some Rocket combos, 2/10s and 1/12. The 2/10s seem to be the ticket right now. Have used the Warehouse 10s and a pair of Eminence Ragin Cajun's, both sound good but the Cajuns are very loud.

Anyway one of the amps came back and the gentleman said it had a "noise" or rattle. I ask what it sounded like and he said a "tinklie" noise. Me....I'm thinking tinklie = glass so it has to be tubes. I plug it in and we heat it up, one of the side benefits to this gig is getting to listen to some awesome players.....and he is. He says ok you hear that and I did.....not loud, but glass. I start replacing pre-amp tubes to no avail. Then I replace the EL84s, Saratov's because I have had great luck with them and the tone isn't as strident as the JJ's. Seemed to have fixed it, until I get a call saying "it's back".I say bring it by and leave it this time. At this point I think its the circuit thats making the noise, so I make sure every thing is secure it the chassis, hit all the solder joints and plug it in setting on the bench. Sounds good, back in the cabinet it goes and there's the noise again. So it's a vibration induced noise. the rect has the cap and spring tube retainer so I put the Fender clam shell type on, still don't help. So I take the EL84 wire type retainer off and the noise can't be found. "It's about damn time".......even as tight as those wire tube retainers are they till vibrated against the tubes. I guess when I swapped tubes and reset the wire retainers it put them in a position that they didn't vibrate against the PTs.

Now the wires have loose heat shrink on 'em and the amp is sounding like its suppose to.

Just thought I'd pass it along............that and a picture.

BL

[Structo]

Yes I have had those wire retainers rattle before as well.

In fact on my Carvin Belair (4 x EL84) I thought I was having filament rattle and a bit of microphonics so I bought some of those silicone dampening O rings.
I put two on each of the tubes.

I thought great I fixed it!

So later figuring it was just the preamp tubes doing it, I removed the rings from the EL84s and reinstalled the wire retainers and it came back.

Combo amps can be very tricky to diagnose tube problems due to the battering the amp gets from the speakers.

[Richie]

fender pro jr comes to mind.. they have a metal top plate on the EL84s and springs pulling down the metal plate. Its a noise machine. Sometimes you just have to find ways to make things work.