Peavey Classic 30 tube glowing red

[rrrip]

Greetings from Russia
I bought a used Peavey C30 few months ago, and it seems to have some troubles in power section. One of power EL84's sometimes starts glowing brightly red, amp starts humming quite loud, while main signal gets really weak. When i just bought it, glowing appeared very rarely, one time a week approx., and since I didn't gig and had lots of other troubles, I didn't do anything with it. Just turned it off for some time when glowing appeared, and after a while it was OK.
But a month ago or so, amp started crackeling terribly, so I had to fix it, since it wasn't playable. Rsoldering tube sockets did the job. I thought I fixed glowing issue too, but it appeared again in a few days. Actually, it starts to appear more and more frequently, thus becoming very annoying. Also, if I'll decide to start gigging, that definitely have to be fixed.
I don't know where to start, because i'm not very good in tube schematics, and also, the problem appears unexpectedly, so I can't even measure anything, since I have to disassemble the amp first.
Oh, and just forgot to mention. I've tried tube swapping, and glowing stays within one socket, it doesn't depend on which tube is in that socket, so the tubes ain't the problem.
So could you give me some advice? I would really appreciate it

[Enzo]

"Ain't?" They say "ain't" in Russia? Oh my...

The tube is losing its bias.

You resoldered the socket in question, but it seems more likely that in that socket one or more of the female pins has lost its grip. Pull the tube, look into the holes amd see if the metal contacts within have spread. Tightening them up would solve that problem.

Another common problem is the little bare jumper wires that connect the sections of circuit boards together - they break. Get under each wire and gently tug outward. ANy that come free were broken and should be repaired. In your case, I don't think that is the trouble since it would affect more than one tube

[rrrip]

Thank you, Enzo! I'll check the socket pins, and soldering also, just to be sure if I didn't forget anything.
I've just googled "Ain't" and looks like I've got your point Well, for some sad reasons, my English practice is now limited by reading and posting on foreign forums, like this one So the word could come to me this way.

[Enzo]

Hey, I was joking. If English is not your native language, you are doing a great job. You fooled me. Ain't is not proper English and is a form used by some rural people, but anyone might use it knowingly just to liven up their speech. So use of ain't would be extremely informal. Which is fine.

When you used ain't I assumed you were a native English speaker in Russia, so I was pretending to scold you like my mother would have scolded me if I said ain't when I was growing up.

When you started with hello from Russia I expected to see a foreigner's English, but you went right along with perfect colloquial English.

If you are seriously working on English, the one thing I did notice when first reading your post which have me a tiny doubt, you left out the artical "the" in a few places. SInce I knew that Russian does not have those articals, it was a clue. But everything else was so good I ignored it.

Here we say "pick up the book." In Russian you would use the words that say "pick up book." It is a very small thing though.

[rrrip]

Oh, those articles always were a headache for me I tend to forget about them.
It's nice to hear good things about my english, thanks! And also big thanks for quick response on amp problem! I'll check my amp and post some results soon.

[rrrip]

So I tried to repair it, and looks like now I've got far more troubles than before. I disassembled the amp, found some bad solder joints again (can't imagine how could I skip over them previous time), resoldered them, put the amp back together, turned it on, and... And was surprised that my long time friend - little hum, which always presented in this amp, disappeared. Even when I raised reverb knob (reverb always add some hum in this one), amp was absolutely dead quiet. These thoughts have been in by head for a few seconds... Then I suddenly remebered that I didn't connect the speaker Of course, I immediately turned the amp off. Next thing I realised was that I plugged in wrong cable - instead of one connected to the guitar, the one connected to nothing Bad, bad luck.. Then I connected the speaker, put the right guitar cable in, but the amp now stays dead quiet... On extreme volume levels I've heard VERY quiet distorted sound. It even could be a mishearing, because it really was very quiet. I've taken out the fuses, they're allright.. So is the tranny dead? How can I check it? What else can I check?.. What a stupid mistake

[Amp Kat]

Ain't is not proper English and is a form used by some rural people, .

It is in the Bayou State. (Louisiana) But sometimes Ain't is confused with Saints but that was the old saints which ain't the aint's any more.

You know we always talk about this but in this case it may be a good idea rip to monitor the bias voltage on pin 2 with your red lead and the black to chassis ground. I believe the 30 is about -18 or somewhere in that vacinity. If the bias voltage is moving towards zero or even less negative around -10 or so you have a bias problem or still a connection prob linked to the bias circuit. Are you sure the tube is good ?

[Enzo]

And make sure you didn't break any of the little jumper wires.

[rrrip]

Thank you for your help!
Now I disassembled the amp again, wandered around with some voltage meter, assembled it back, and wow - it works! Did I scare my amp with those red and black leads coming from my multimeter, so it immediately decided that it'd be better to work?
Being serious, that disturbs me - what can I do with the amp that can suddenly become silent? I can't depend on it! Inside, everything looks fine - no bad solder, no broken jumper wires, nothing bad.. But also, I might have done something wrong when assembled it previous time, since it was overall unlucky assembling
I did measure bias voltage, it reads -12VDC. But I pulled one tube out - i think this could affect the result, since all other power tubes became dark, just if I didn't turn the amp on at all - maybe lots of voltages did change. Not sure, though... And with all tubes installed, they don't seem to bee too hot - seems like a normal working condition.
So is anything more possible to be done with the amp? Otherwise, looks like I'll have just to use it, and wait for some problems to appear.
Sorry for disturbing, but looks like I need a little more help..

[oc disorder]

The EL84 filaments/heaters are in series

Hello.. the power tubes went dark when you pulled one out as the heaters
are all in series. 6volts+6v+6v+6v =24volts AC .
That way the transformer is cheaper to make.
The two red wires from the transformer provide the high voltage for the anodes or plate and the two orange wires provide the low voltage for the heaters , bias , I.C.and relay supply.
A good test at home or rehursal should show if you can depend on it.
A spare set of output valves is probably a good idea ,most working musicians
should do this but I don't think many do...;-) !