Quad JJ 6550s - 2 outers hot / 2 innards cold- switch around ?

[73 super lead steve]

as advised, I took the outer two tubes that showed sings of run-n hot and switched them over to the two sockets with the two tubes run-n cold, symptom did not follow tube change, plus just out of curiosity I took a quad plug bias tester and came up with some conflicting results 1st outer tube came up 20 - 2nd tube 22 - 3rd 8 and 4th 11, I rectum lol, this is in plate dissipation ? my tester does not show plate voltage and plate current but just dissipation ? I'm not to sure about sending the amp back to the same tech who resides in the same building as the Willis Music store in Florence Ky. I might have to eat the cost of have-n the New power tubes/pre amp/and filter caps installed ? I'm begin-n to think he just slap them in without check-n the bias after the install, the real question is, are the - use- to be brand new tubes still any good after that ordeal ? PS I am gonna get hold of Willis Music and see if I can get some kind of reimbursement I'm not gonna hold my breath!

 

[SpiderWars]

Are you saying that the filaments do not light up or that the tube never gets really hot? You keep saying 'cold' but I've never had a tube with filaments lighting up that was 'cold'. It might not get super hot but it's certainly not cold. I thought this whole time that the filaments were not lighting up but above you say that there is a small amount of current. In any case, those numbers are way low and not matched.

Do you know what your wall voltage is? Seems highly unlikely but if the tech biased it at a high wall voltage and yours is low then that could explain some of it.

 

[Chris6870]

Could be screen grid resistors.

 

[73 super lead steve]

Are you saying that the filaments do not light up or that the tube never gets really hot? You keep saying 'cold' but I've never had a tube with filaments lighting up that was 'cold'. It might not get super hot but it's certainly not cold. I thought this whole time that the filaments were not lighting up but above you say that there is a small amount of current. In any case, those numbers are way low and not matched.

Do you know what your wall voltage is? Seems highly unlikely but if the tech biased it at a high wall voltage and yours is low then that could explain some of it.

All the filaments are lighting up, The logos on two tubes look brand new ,the other two logos look like they have had a lot of heat to them, I let it run for 15 minutes the two that looked hot where warm to the tough, the other two (tepid) though one of the tepid tubes filament was a lot more brighter at the top than the others?

 

[73 super lead steve]

Could be screen grid resistors.

The screen resistors is gonna be my next move, looks like I'm gonna have to yank it back out and do some check-n, I visited the shop when he had it on the bench and did happen to noticed he replaced one of the screen resistors the other three looked originals to the amp, of coarse I'm not an amp tech, and I don't claim to be, that's why I am gathering info on this subject, Before I had all items replaced, I was gig-n one night at a club and the amp popped a 4 amp fuse, no smoke or smell of melt down ,took the back panel off and noticed one of the 6550s showed signs of red plate-n and one of the filter caps blew it's plastic coating off of the top, my next move was to get new matched power tubes/new 12ax7s/and new can caps, then took it to the tech told, him what happened that night, plus mentioned I had new parts to put in, due to the amp set in storage for almost 30 years from the original owner who I had bought it from, I took it that everything dried out and it would need these items anyway, then ask the tech could he correct the problem the amp was have-n He said shouldn't be no problem, called me up and said amp was finished took it out, played it on two gigs brought it back to the house ,took the back panel off to see the new stuff and seen that the brand new logos on the power tubes ( expecting to see some darkening ) and noticed two of the tubes still had a bright fresh color to the logos lost for words ( that might be an understatement lol

 

[cardinal]

I had an old Super Lead that was red plating a pair of tubes. A tech tried to help me trouble shoot via email. His immediate thought was to make sure the sockets are in good condition and perhaps replace them. I ended up returning the amp so I never chased down the problem.

 

[73 super lead steve]

I had an old Super Lead that was red plating a pair of tubes. A tech tried to help me trouble shoot via email. His immediate thought was to make sure the sockets are in good condition and perhaps replace them. I ended up returning the amp so I never chased down the problem.

Mr C I had all ready cleaned all the power sockets and re tighten the pins, this is an old - new 1977 Marshall mk2 master model 2203 I am the second owner, the original owner bought it brand new from a music shop in 77, two months after he bought it he got injured in a work related event injured his back and could not move the amp around, so he stuffed it in his finished basement that year and there it sat until 2005,he thought his back would get better but it didn't needless to say all the insides dried out caps/tubes etc. took it to a tech to replace all got it back and played a couple of gigs then one day out of the blue, i decided to check the new tubes out and noticed two of the inner tubes where look-n brand new, and the two outer tubes looked like they had been through the mill logos on tube looked darken , I have a quad bias checker but it only tells you the plate dissipation ,the #s where all different 9/11/22/20 do you know a you tube site that shows how to bias that year model ?

 

[73 super lead steve]

Are you saying that the filaments do not light up or that the tube never gets really hot? You keep saying 'cold' but I've never had a tube with filaments lighting up that was 'cold'. It might not get super hot but it's certainly not cold. I thought this whole time that the filaments were not lighting up but above you say that there is a small amount of current. In any case, those numbers are way low and not matched.

Do you know what your wall voltage is? Seems highly unlikely but if the tech biased it at a high wall voltage and yours is low then that could explain some of it.

No Im not say-n the tubes don't light up, the filaments all light up and the wall voltage is 120v ---2 tubes are run-n hot--- the other 2 are not, pardon the cold remark all i know is, if you touch the to hot tubes your gonna get burnt, if you tough the other 2 your not BUT 1 of the tubes that doesn't run hot has the filament glow-n a little red-r at the very top of the tube most of the sites on you tube all show amps with tube rectifier none with solid state rectifiers, just look-n at the best way to solve the problem of the off the wall dissipation #s I'm get-n

 

[73 super lead steve]

Could be screen grid resistors.

they all checked out to specs?

 

[panhead]

Put another set of tubes in it , the tubes are probably not matched.

 

[Chris6870]

Make sure your tube sockets are tight. I had this happen before. Some tubes have pins that are a little wider and stretch the sockets. When you put another tube in they don't make good contact since the sockets are stretched. You can take a pick tool and squeeze them back tight. Upon further reading looks like you may have already tried that?