Care and Feeding of Tube Pins / Sockets

[gingertube]

On the weekend I turned on my 845 SET and one channel didn't work. A small jiggle of the 6SN7 driver tube in its socket and all came good.

I've checked the socket wiring for dry/bad joints etc and all is OK -so its the sockets/tube pins that require attention.

Is there a recommended contact cleaner for this purpose?
Should I be trying to close up the socket contact fingers using brute force and ingnorance?

Any guidance greatfully received.
Cheers,
Ian

[Layberinthius]

If you have the spare time, Get some WD40 and while the set is unplugged on your bench and on it's side, spray the pin contacts and then clean the inside and outside of your amplifier with a cloth of the excess WD40 while you are inserting and removing an old Octal tube that you know is dead, do this a couple of times but not excessivley, you don't want to weaken the tension of the socket pins too much by this method so be careful, of course taking first caution to your own personal saftey, WD40 won't ignite unless you have a naked flame directly infront of the can, which it isn't the WD40 solution that would burn but it's the can's propellant gas.

So don't smoke while doing this.

If this doesn't work and you still get dropouts when you tap the side of the tube in question, replace the socket with a better quality one or of New manufacture.

I personally would prefer not to bend the socket pins as it's generally not a good idea, too much tension and you can tear off a tube pin without even knowing it, too little and it can lead to a tube falling out in transit or some such stuff.

P.S. Repeat after me, under no circumstances will you use engine cleaner or any other solvent other than WD40, WD40 is good, WD40 is wise.

[Zappa]

Originally posted by Layberinthius
WD40 is good, WD40 is wise.

Maybe WD40 can get some grime off the contacts other solvent can't, but if used, I would at least then clean the socket with Tech Spray or equivalent (pure isopropyl alchool) product to get rid of the WD40 water and oil residue...

[Layberinthius]

Originally posted by Zappa


Maybe WD40 can get some grime off the contacts other solvent can't, but if used, I would at least then clean the socket with Tech Spray or equivalent (pure isopropyl alchool) product to get rid of the WD40 water and oil residue...

Yes that is exactly what I use "Nail polish remover" with a tissue and cotton bud, I was going to recommend it aswell but NPR brands differ in their makeup too much to pin one down, if you've got plastic tube sockets you can melt the plastic with some brands of that unfortunatley.

Not to mention remove the paint off the amplifier chassis or de-galvanise some steel, hehe

So I recommend some caution with brands of NPR, I use Bi-Lo and that has done well for the past 5 years but you never know.

[gingertube]

Thanks for the above.

Nail polish remover is generally acetone based. It will melt capacitors and all sorts of stuff. I don't think its a good idea to get it anywhere near an amplifier.

I have both WD40 and Isopropyl Alcohol.

I'll try the Isopropyl alcohol on its own first and resort to the WD40 (I'll have to get it out of the garage where I use it for car parts) if necessary.

It was the residue issue which put me off trying the WD40 first and instead ask for help.

Thanks,
Ian

[Sherman]

Originally posted by gingertube
...

Is there a recommended contact cleaner for this purpose?
Should I be trying to close up the socket contact fingers using brute force and ingnorance?

Any guidance greatfully received.
Cheers,
Ian

Ian,
I use an electronics cleaner I got from Fry's but there are lots of other brands. The nice thing about it is that it isn't electrically conductive. No worry about shorts etc. from caps that might not be fully discharged. It also removes not only dirt but also oxidation.

I used it to clean some extremely scratch pots in an old tube radio. They were so bad I expected to have to replace them. A quick squirt of the stuff into an opening in the pot flushed quite a bit of grime out. I turned the pots stop to stop several times, squirt in a bit more and dried it with a paper towel and a cotton swab. Result? Perfectly quiet pots!

Since then I've been sold on "real" electronics cleaner.

[sanford1]

Hi-temp Caig Pro-gold GxL contact cleaner http://www.partsexpress.com/pe/pshow...=341-228&DID=7
is worth a look.

I normally just use DeOxit and pipe cleaners after isopropyl alcohol, but this stuff may be ideal.

[fdegrove]

Hi,

Should I be trying to close up the socket contact fingers using brute force and ingnorance?

That may work in some cases but hardly ever does much good in the long run.
Basically it usually depends on the type of contact the socket has but if it's of the semi-circular type and it was bent open with a slightly oversized pinned tube, plying it back won't guarantee a decent contact in the long run.
Those are the kind of sockets I avoid like the plague anyways.......

If you suspect the contacts to be bent out of shape I'd recommend replacing the entire socket with a decent one.
The Russian made ceramic ones (octals and novals) are the best you can buy; contacts are silvered brass (?) and have a flat "lyra" shape that just can't be abused unless you're really looking to destroy it.
Other than that they're pretty bomb-proof.

As for contact cleaners, if you plan on a massive/aggressive cleaning it's best to do this with the socket removed from the amp, clean it with something like WD40 and old toothbrush scrubbing, apply some contact enhancer such as Cramolin and put it back in.

Cheers,

[Layberinthius]

Originally posted by Sherman



Ian,
I use an electronics cleaner I got from Fry's but there are lots of other brands. The nice thing about it is that it isn't electrically conductive. No worry about shorts etc. from caps that might not be fully discharged. It also removes not only dirt but also oxidation.

I used it to clean some extremely scratch pots in an old tube radio. They were so bad I expected to have to replace them. A quick squirt of the stuff into an opening in the pot flushed quite a bit of grime out. I turned the pots stop to stop several times, squirt in a bit more and dried it with a paper towel and a cotton swab. Result? Perfectly quiet pots!

Since then I've been sold on "real" electronics cleaner.

If you're thinking what I think you're thinking, WD40 isn't electrically conductive, at least not to the point that it would matter, you're not going to be spraying it on PCB's anytime soon unless you're thinking of a scratchy pot inside a preamplifier, thats the least of your problems the pot shouldn't even get scratchy at all as by rights it should have been oiled or greased before service, and last 30 years after, what's changed?

Generally a small nip of the stuff in a pot and on the pot shaft then a couple or more turn-overs and, yes, I too have squeaky clean pots.

I personally wouldn't remove a valve while the unit is on, spray the socket with WD40 and re-insert said valve like my uncle has done, but I'll get to the point he's worked on valve units for 84 years and I didn't hear him complain recently about greasy oily WD40 shorting out his most valuable 1920's sets...He is 96 and has collected since he was 12.

I'm not one to go into town for a 30min drive to get the stuff you speak of, and then paying $9.95 for it not including travel costs eventually you end up spending about $40 for two cans of the stuff: Jaycar cleaning solvent

I'll stick with my cheap(er) and oily stuff available from anywhere

[cogsncogs]

Hello

I use DeOxit and 91% or better isopropyl alcohol which can be obtained at any good pharmacy (chemist), never WD40. WD40 is good for removing grease and other oils, wonder why? Could be something on the order of kerosene and the like... I leave that and liquid wrench for my garden tiller and the like! I don't like to use it in electronic equipment because it "attracts" dust and other containments if not completely removed. Also acetone (nail polish remover) and paint thinner is out of the question. If you want to use something from the "automotive" department, try some of that spray silicone. But beware it may contain acetone which can dissolve many plastics.
Nine pin novars I can usually tension them back to life, but as for octals it's better to replace them all-together. Nine pin sockets become "loose" by constant tube rolling, i.e. trying different brands/types, listening for a different flavor or better sound. More so with constant swapping of tubes with bent pins.

Cheers
Wayne