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
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
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.
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 said:
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.
Ta!!
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
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
gingertube said:
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.
Hi-temp Caig Pro-gold GxL contact cleaner http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=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.
is worth a look.
I normally just use DeOxit and pipe cleaners after isopropyl alcohol, but this stuff may be ideal.
Hi,
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,
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,
Re: Re: Care and Feeding of Tube Pins / Sockets
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
Sherman said:
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
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
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
I still have Cramolin on hand, but can also say that I've been in tight spots before and used Brasso (metal cleaner for cleaning copper pots, etc.) with good results. It seems to leave a light oily deposit, so cleaning afterwards to get the residue off is a good idea. I'm not recommending this for long-term use, just something to get by or to deal with really, really corroded contacts when you don't have a replacement socket on hand.
Toothpicks work well for twirling in 9-pin sockets. Nab a woman's mascara brush and clean it up for use with octal sockets. In emergencies I've used Q-tips with the cotton pulled off the end for octal sockets.
WD-40 is not good. WD-40 is not wise. WD-40 is setting the stage for future problems. Ugh. Might as well use motor oil.
Grey
Toothpicks work well for twirling in 9-pin sockets. Nab a woman's mascara brush and clean it up for use with octal sockets. In emergencies I've used Q-tips with the cotton pulled off the end for octal sockets.
WD-40 is not good. WD-40 is not wise. WD-40 is setting the stage for future problems. Ugh. Might as well use motor oil.
Grey
Careful with the isopropyl alcohol from drug stores, since it's meant for external use more often than not it contains (IIRC) lanolin. Try some on a piece of clean glass first, pure alcohol won't leave a residue.
My preference is methyl hydrate, a tip picked up from television broadcast techs twenty years ago. They used it as a headcleaner for Beta machines so you know it dries clean.
My preference is methyl hydrate, a tip picked up from television broadcast techs twenty years ago. They used it as a headcleaner for Beta machines so you know it dries clean.
Thank You
Thanks One and All.
I've now been talked into WD40 and then talked out of it again.
In the end I had a look to see what was on the shelf in the electronics lab at work and borrowed the CRC CO Contact Cleaner.
It says on the can "No Residue" and also says "Suitable for Video Heads,....,PC Cards/Modules - sockets & plugs,...."
Work owed me a few cents anyway for the new fuses I put into the aircraft ground power cart (28V DC at 1000 Amps) yesterday, so now we're square again. I had to get the bloody power cart going again so I could finish some laser tests in survey aircraft.
A cautionary story about using Acetone:
A few years back I had to clean a KTP frequency doubling crystal for the Nd:YAG laser. I wiped it over with acetone and the crystal promptly shattered. I knew the crystal was sensitive to thermal shock but did'nt think the rapid cooling due to acetone evaporating would be enough to cause a problem. I was unpleasantly (and expensively) surprised.
Cheers,
Ian
Senior Electronic Engineer,
Laser Airborne Depth Sounder
Thanks One and All.
I've now been talked into WD40 and then talked out of it again.
In the end I had a look to see what was on the shelf in the electronics lab at work and borrowed the CRC CO Contact Cleaner.
It says on the can "No Residue" and also says "Suitable for Video Heads,....,PC Cards/Modules - sockets & plugs,...."
Work owed me a few cents anyway for the new fuses I put into the aircraft ground power cart (28V DC at 1000 Amps) yesterday, so now we're square again. I had to get the bloody power cart going again so I could finish some laser tests in survey aircraft.
A cautionary story about using Acetone:
A few years back I had to clean a KTP frequency doubling crystal for the Nd:YAG laser. I wiped it over with acetone and the crystal promptly shattered. I knew the crystal was sensitive to thermal shock but did'nt think the rapid cooling due to acetone evaporating would be enough to cause a problem. I was unpleasantly (and expensively) surprised.
Cheers,
Ian
Senior Electronic Engineer,
Laser Airborne Depth Sounder
Ok, let me clarify. Buy the alcohol meant for injections. It can range from 91% to 94%, and does not contain "lanolin", only distilled water. Rubbing alcohol is the one to avoid as it contains "glycerin" and sometimes green dye and is usually around 70% in the US anyway. I also use it to clean the heads on my reel to reel's and VCR's.
Wayne
cogsncogs said:Rubbing alcohol is the one to avoid as it contains "glycerin" and sometimes green dye and is usually around 70% in the US anyway.
Wayne
Ooops, glycerin. Right you are. Hey, I'm an engineer Jim, not a doctor!
On the other hand, not being labeled rubbing alcohol doesn't guarantee purity. Ironically I ran into a situation at work just two days ago where a jug of alcohol from a pharmacy, labelled 99% pure, was discovered to leave a heavy greasy residue. Presumably the remaning 1%.
I guess it just depends on what "brand" and where you purchase it. I don't recall running into that greasy residue problem... lucky I guess. I would say in light of this it would be wiser to purchase isopropyl alcohol meant for cleaning tape heads from an Electronics supply store. The bottle of 91% isopropyl alcohol I have setting in front of me lists the ingredients as 91% alcohol and water, bought from Wal-Mart manufactured by: Cumberland Swa(?) can't make out last letter, Smyrna TN. I've had good results with this brand. Also great for removing excess rosin from PC boards etc.
Wayne
Bump...
Related but slightly different problem.
I've noticed a number of NOS tube sockets from the 60s/70s that are tarnished. I bought some at a Ham Fest a couple of years ago and they gave me immeasurable grief.
I ended up pulling the sockets and replacing them.
Does anyone know of a way to clean the pins of these sockets? The pins don't even solder well, and the socket portion is obviously tarnished to the point of being unreliable electrically.
Plating looks like tin or silver. Oxide is tan to brown.
Related but slightly different problem.
I've noticed a number of NOS tube sockets from the 60s/70s that are tarnished. I bought some at a Ham Fest a couple of years ago and they gave me immeasurable grief.
I ended up pulling the sockets and replacing them.
Does anyone know of a way to clean the pins of these sockets? The pins don't even solder well, and the socket portion is obviously tarnished to the point of being unreliable electrically.
Plating looks like tin or silver. Oxide is tan to brown.
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