Tracing noise problem, TwinRev.

[Sea Chief]

Pins erm, these pins... crack goes from one to the other ( marked green), kind of missing out the pin in between..

[nosaj]

ok Not wanting run through 7 pages.. With tubes in does wiggling any of them cause noise or remove noise with it on.
Looks like crack goes from pin2 to pin4 I think so thats heater and screen grid.

Do you have a new socket on the way?

[Sea Chief]

ok Not wanting run through 7 pages.. With tubes in does wiggling any of them cause noise or remove noise with it on.
Looks like crack goes from pin2 to pin4 I think so thats heater and screen grid.

Do you have a new socket on the way?

Hi sorry its run on a bit. No I was asking if anyone knew what sockets fender used/ screw holes need identical matching I think?

I will try wiggling tubes tmrw. And/ or rebemd the socket pins or spmething?

[Chuck H]

Well that seems to photograph just fine. Clearly visible.

But the fact that your tube swapping and checking individual power tubes with individual sockets made no difference is indicative that this is not the problem. Though (as you have already acknowledged) the cracked socket and the charred socket need to be addressed. But if putting any single tube into the undamaged sockets didn't stop the noise it seems unlikely that this is your problem.

Is what I described above the nature of your experiments/testing?

[Sea Chief]

Well that seems to photograph just fine. Clearly visible.

But the fact that your tube swapping and checking individual power tubes with individual sockets made no difference is indicative that this is not the problem. Though (as you have already acknowledged) the cracked socket and the charred socket need to be addressed. But if putting any single tube into the undamaged sockets didn't stop the noise it seems unlikely that this is your problem.

Is what I described above the nature of your experiments/testing?

Hi. Chuck. Yes exactly what I think too/ spot on with your description.

So might the idea now be to put all tubes in, then go across pulling v1 to v6 out to see if the noise stops at any pull?

Also thinking onwards only from logic here, I think/ by looks of it, I reused the rectifier board & possibly the filter board too ( rejigging both boards components ) when I rebuilt the whole amp. Now when 'new again' reborn, tested great/ no noises/ behaved properly for 1.5 yrs approx.

So considering this latter-test stage, this last area to consider having exhausted all prior tests (i hope still ongoing).. just a few of my thoughts. I'd have thought sending my tubes to a tester/ someone who could test/ might seem a sensible step beforehand-? And replacing the socket just for peace of mind really.

Thanks, SC

[Chuck H]

I'm not suspecting tubes right now since you have other symptoms that are not likely tube related. Specifically the volume loss with only V1 and V6 in place. Since you tried different tubes in V1 and the volume loss persists there's something not right about that.

There are some prior tests requested and I'm not sure now about the outcome. It's a long thread. So if you could recap a couple of things for me please...

Did you pull V1 (leaving only V6 and the power tubes in place) and twiddle the normal channel volume? And if yes what happened?

Did you ever "chopstick" the components?

[Sea Chief]

I'm not suspecting tubes right now since you have other symptoms that are not likely tube related. Specifically the volume loss with only V1 and V6 in place. Since you tried different tubes in V1 and the volume loss persists there's something not right about that.

There are some prior tests requested and I'm not sure now about the outcome. It's a long thread. So if you could recap a couple of things for me please...

Did you pull V1 (leaving only V6 and the power tubes in place) and twiddle the normal channel volume? And if yes what happened?

Did you ever "chopstick" the components?

Hi Chuck, yes I apologise for the long thread.

Have I got somewhere though..? Ok I just did what you said here, only V6 & the 4x power tubes in. No noise. Twiddled normal vol.. no noise.

What I did do just before putting these 5 tubes in, was bend power tube pins in a bit.. as much as I dared/ not ideal levering a tiny jewelers screwdriver gently against ceramic socket making an uncomfortable crunching! Ok tho.

And Rift are sending me out a new V8 socket ( yes he did replace all 4 back 3 yrs ago he said ).

So is this some progress at last? Thanks for your patience/ reading my drivel. SC

[Sea Chief]

Chuck H ..then I put V1 back in too ( so v1, v6, & power tubes in ), & noise back with a vengeance. Urgh.

Does this no noise with v1 pulled just beforehand, give any more indicators tho? Thx SC

[Sea Chief]

Now something seems different: I put back all tubes, apart from V1.

Different noise.

Now I don't get the LOUD crackles, but instead a steady prominent 'errrrr' ( sounds morelike a grounding thing), with some mild distortion behind.

How frightfully queer. SC

[Sea Chief]

I go along pulling v3, this different groundy noise thing there. Then pull v4.... & no noise.

----------

So to recap:

1. big LOUD original crackling noise with awful occasional VERY LOUD POPS, with all tubes in,
2. noise changes to a different ' prominent groundy ERRR, with mild distortion' once v1 pulled.
3. this noise ceases to no noise, once going along & once v4 pulled.
4. same no noise with v5 pulled.

Thanks chaps, SC

[Chuck H]

Does the amp make loud pops with the volume up a little if it's just sitting there? No twiddling the volume.

I mentioned chopstick testing. Have you done this? If not I think you'll really hate it With the amp open, on and tubes in you have to use a non conductive stick (like a chopstick, absolutely not a pencil) to poke all the components, pot connections, tube socket lugs and board lead connections to see what happens. With a possibility of loud pops with each poke. You'd be poking stuff in the preamp associated with V1 through V4.

Though I have to wonder what has happened in the amps power circuits to cause char on one power tube socket and a crack in another since the amp hasn't been used a lot since they were replaced. But this doesn't seem to be the problem at hand.

[Sea Chief]

Chuck H so with just v1 pulled you mean?

You see now it's making 2 different noises ( 1 entirely new to me ) with different tubes pulled, as outlined above (1 - 4).

I should have added all my recap findings are without gtr plugged in.

[Chuck H]

Guitar plugged in vs guitar not plugged in will change how the input jack wiring is included. It doesn't matter for the chopstick test because bad contacts should show themselves either way.

You'll want all tubes plugged in.

And, FWIW, you shouldn't intentionally skew tube pins to try and effect contact. Bad for the tubes and especially bad for the sockets because it fatigues the little inserts. Bad connections here should be diagnosed by gently rocking the tubes in a sort of circular motion in the socket and addressed as they occur.

I don't have any diagnosis based on your findings above with the exception that the problem at hand seems to be limited to the preamp.

[Sea Chief]

Guitar plugged in vs guitar not plugged in will change how the input jack wiring is included. It doesn't matter for the chopstick test because bad contacts should show themselves either way.

You'll want all tubes plugged in.

And, FWIW, you shouldn't intentionally skew tube pins to try and effect contact. Bad for the tubes and especially bad for the sockets because it fatigues the little inserts. Bad connections here should be diagnosed by gently rocking the tubes in a sort of circular motion in the socket and addressed as they occur.

I don't have any diagnosis based on your findings above with the exception that the problem at hand seems to be limited to the preamp.

Chuck, considering Im not having amp on for very long each test, could I Unplug one spkr do diminish the volume? Cab Already facing the wall.. but still hellish loud pops. If I could diminish the vol right down, poss makes it pallatable. At the mo I dare not poke anything even with ear goggles on.

Thanks, will put tubes back in then. At least Ive got - somewhere- different today.

[Chuck H]

Since you'll be poking the preamp components you could remove two power tubes (one from each end of the OT as discussed) AND unplug one speaker. That should quiet it down a little and you'll still have a matched load.