Choices in Tube Socket Replacements

[GAR]

http://oldtube.com/Philips-6CA7-quad.jpg

My power tubes on one amp keep getting fucked.. and I don't have a vast stash of 'em to keep playin' around trying to see what's going on.

I called a few techs, 2 of the 3 agree it sounds like "octal carbon buildup."

http://www.skoudata.dk/1987/picture014.jpg

Because of the heat buildup - dissipation cycles that power tubes go thru, if you use 'em alot you run risk of filth in your air (such as my chick's cigarettes to the casual dust in everyday air or even indoor pollution such as fried foods, heater and/or gas water heater exhaust leakage etc) drawing down on the tube pin contacts in the actual PATH of the electricals, until buildup creats an arc to ground.

I couldn't believe this, it sounded like bullshit so I had to check it out and yank a few chassis.. and there, lo and behold the trouble existeth - little black tobacco stripes from a few pins going out to the chassis and other pin points like the air wiped its ass on my amp and fucked it up to ground out one of four tubes.

So the guys that gave the correct analysis to the symptom, suggested since I know what I'm doing just to go ahead and replace the tube sockets.

I know what I'm doing with a soldering iron if I'm picking my teeth or cauterizing my bacne oozings, but if they think I can do it then I guess I gotta do it or pay the piper, $125 to one guy or $250 to the other guy.

Which, basically amounts to name-brand since the higher dude would do it fullproof and rebias, and all that crap I cannot do..

So: it comes down to 3 choices of socket

- white plastic, most commonly used modern amp use
- white ceramic, most common replacement
- brown micalex, least expensive moderate insulator
- brown bakelite, most expensive and most insulative

http://www.tubeampdoctor.com/images/SOCKETS/s8C-1-TAD.gif

Here's my cost on these things:

- white plastic, .85
- cheap ceramic, .80
- good ceramic, 3.75
- brown micalex, 1.40
- brown bakelite, 7.95

So what is SOO special about Bakelite that it's almost 8 bucks a socket?

I thought - and this is going back 25 years - my recollection from the classroom sheet it was Mica to be the best electricity insulator in all the chemistry elements tables.. so shouldn't mica-impregnated plastic parts be the better thing to have in an amp?

http://www.kaponk.com/files/ao8-omron-socket-01.jpg

I got 5 heads out on the floor tonite lookin at em while my chick is bitching about my mess, so I'm trying to make a quick job of this parts order.

I'm thinking of just redoing all of them, and if I can't get a drastic improvement just buy all new amps.

I'd avoid this if I could.. anyone had major service like this know what to do with weighing out the differences of the type of socket from 5 to select here?

[Diamondjimi]

Hyper-linking to other peoples shit.........weak..... :shiznit:

[GAR]

I can only do so much in a day..

[Nitro Express]

It really doesn't matter. Unless the tube has arced and left a big carbon deposit or mealted the socket the electrons are going to flow. If your contacts are oxydized or dirty just pull the tubes, spray some Deoxit on the pins and plug them back into the same socket. You would be suprized how many problems on an amp are fixed by spraying some Deoxit.

One thing about bakelite is it never chemically deteriates. If have restored old cars and outboard motors from the 1920's and 1930's and the bakelite electrical parts are like new. Then I've restored stuff from the 1950's and 60's and the plastics have chemically deteriated. Ceramic sockets have the problem of arcing if they get dirty but it's trivial. If your amp is in a smokey environment clean it once a year. Discharge the caps and clean the pots, jacks, and tube sockets and this will eliminate a lot of problems.

[ZahZoo]

"octal carbon buildup."

Simple solution... works best in an enclosed space. Saturate the sockets in gasoline and let soak for 24 hours. Then ignite with a blow torch. This will quickly remove any carbon buildup...

[GAR]

Notice I didn't say "rectal carbon buildup" Zah, please stay focused with us.

[GAR]

..spray some Deoxit on the pins and plug them back into the same socket. You would be suprized how many problems on an amp are fixed by spraying some Deoxit.

You know, I'm usually the one to suggest such a thing on other boards yet - when a qualified amp engineer tells me "oh you should replace the sockets" that kinda throws one for a loop.

Mainly because they should be the very first ones to suggest Deoxit, right?

I guess I just needed that extra bit of confirmation, thanks Nitro. But I've also got to confess that since Jay's Boogie thread about the new Mark 5's, I'm leaning towards replacing these if I could get some kinda of low-level endorsement discount. And only if I could go for a few days up to Petaluma and have my heads voiced at the factory.

I know like everyone here how fundamentally metal the classic Mark 2C is, and the new Mark 5 comes close but not close enough in it's stock form: it's a little cold sounding and I don't mind burning tubes obviously if I get the sound I want.

Which is why I don't play, my amps sound quite faded and every one of them need about $400 bucks worth of parts.

If I could get 5 Mark5's for a cost of $1500 each, instead of wasting a lot of time and money revoicing these things would I still do what I'm doing? Would you, just for the uniqueness factor of having something different?

[ThrillsNSpills]

blah blah shoobeedoo flappa jeeba nothing nothing pay attention to me pay attention to me



Which is why I don't play,



Bingo is that your final answer, survey said, tell her what she's won Johnny.





locked dumped next any questions

[GAR]

About as insightful as you can get there, TNS?

[Diamondjimi]

[img].

I'd avoid this if I could.. anyone had major service like this know what to do with weighing out the differences of the type of socket from 5 to select here?

Help hint in identifying faulty sockets GAR. Plug the fucker in and stick your tongue in , the same way you'd test a 9v battery.

If you cease to post here anymore, it can only mean one thing...you've solved the problem.

I'm serious. Trust me!

[GAR]

WRONG it keeps blowing fuses, and if I do the "foil-over-fuse" trick, I blow a tube.

[Nitro Express]

Sometimes the pin socket contacts get bent out and you get intermitant contact. Just bend them back in. If you have good physical contact, clean connection, and no carbon causing a short any socket should do the job.

[GAR]

I've done a number of things:

- pulling one, or the other pair of tubes, same socket blows
- replacing fuse w/higher rating (1a, 3a, 5a, 6a) and it blows
- polishing tube pins with Scotch-Brite greenpad, still blows
- retouched socket contacts w/soldering iron, still blows
- checked impedance of bias resistor, all 4 are within 3ohms of ea. other

I'm doing the Deoxit thing next but I'm fairly certain to change the sockets anyways.

Which would be best choice?