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    Tube/socket contact

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    wildiowa

    Posts : 126
    Join date : 2012-03-19

    Tube/socket contact

    Post by wildiowa on Thu Jan 15, 2015 12:26 pm

    Was listening to tunes on a tube amp (not a Dyna) at low level the other night when it went dark. Slight electronic smell. Thought the worst but blew a fuse and ran it a couple of hours yesterday with no issues but still a slight smell. I am going to check some voltages later today to see if there was a stressed tube or other problem I can trace.

    In the past I have used some DeOx by Caig (brush on) to lightly coat the sockets and tube pins of all my tube amps for what I thought was maintaining good electrical connection and contact. Now I am not so sure. In taking the tubes out I noticed what looks like oily funk around the sockets down below and wonder if this might be the problem by losing tube/socket contact and creating a momentary surge or whatever.

    I have a very small set of round files originally intended to clean acy/oxy torch orifices which I use to file bone guitar nuts, and wondered if I would be better off to rough the sockets and pins a bit with this file rather than using the gunk, no matter how well intended....or is the Caig stuff good, even though it leaves a bit of residue?

    I am trying to make sure this doesn't happen again and thinking of all possibilities. Could have just been a line surge. Anyone got thoughts on this?

    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Tube/socket contact

    Post by deepee99 on Thu Jan 15, 2015 3:57 pm

    wildiowa wrote:Was listening to tunes on a tube amp (not a Dyna) at low level the other night when it went dark. Slight electronic smell. Thought the worst but blew a fuse and ran it a couple of hours yesterday with no issues but still a slight smell. I am going to check some voltages later today to see if there was a stressed tube or other problem I can trace.

    In the past I have used some DeOx by Caig (brush on) to lightly coat the sockets and tube pins of all my tube amps for what I thought was maintaining good electrical connection and contact. Now I am not so sure. In taking the tubes out I noticed what looks like oily funk around the sockets down below and wonder if this might be the problem by losing tube/socket contact and creating a momentary surge or whatever.

    I have a very small set of round files originally intended to clean acy/oxy torch orifices which I use to file bone guitar nuts, and wondered if I would be better off to rough the sockets and pins a bit with this file rather than using the gunk, no matter how well intended....or is the Caig stuff good, even though it leaves a bit of residue?

    I am trying to make sure this doesn't happen again and thinking of all possibilities. Could have just been a line surge. Anyone got thoughts on this?

    Well, always apply Occam's Razor first, coulda been just a line surge, a one-time event, albeit scary.
    Second thought would be that by reaming your sockets holes you've expanded them, and they are losing contact with the tube pins. Take an eye-doctor's sized screwdriver to the individual pin-grabbers on each socket-hole and push 'em back toward the centre. It's a tedious and boring project, but will yield you results. (BTW, do this whilst powered-off.) No amount of DeOxit is going to make your electrons jump across an empty canyon.
    So take that itty-bitty screwdriver and gently move those contacts towards the centre hole a bit.
    Beware that, if you're tube-rolling, every similarly-named tube pin has a different diameter and the fat ones (Russian KT-120s) can blow an open hole where an old Tung-Sol 6550 would fit but not make electrical contact. Make their sockets as snug as possible.
    I have lost a lot of magic smoke learning this process.
    Cheerio,
    David






    sKiZo

    Posts : 1310
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Tube/socket contact

    Post by sKiZo on Thu Jan 15, 2015 4:14 pm

    I dampen a pipe cleaner with D5, drag that in the hole a bit to spread it around, let it sit a bit to loosen things up, wet it again, and just use the tube itself to clean and polish the contact areas while the D5 is still damp. The contact tabs aren't gonna be perfectly round, and the friction from the pins doing the old in and out should be enough to get a perfect match to the tube.

    Goes without saying, this should be done after re-tentioning the sockets, and any time you change tubes. Don't get too carried away bending the fingers in the socket - I have a small screwdriver that slides nicely behind the tab, and a quarter twist is enough to push the finger back towards the center. The tube should slip in under fairly firm pressure.

    Little tip ... I spray some D5 in a needle bottle and use that instead of the can. Less overspray and a little bit goes a long way. If you do use the can, always leave the spray setting to low.

    Also, straight in and out. Avoid rocking the tubes in the sockets as that's where the fingers get wonky.



    deepee99

    Posts : 1333
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Tube/socket contact

    Post by deepee99 on Thu Jan 15, 2015 4:24 pm

    Oh, I dunno about that rocking thing.
    Glass comes off the powered-up guts, ensuing very spectacular light show. Fuses and rectifiers go pear-shaped and sometimes you get a very loud KERPOW sound.
    Who with a sand amp can claim such fun?

    wildiowa

    Posts : 126
    Join date : 2012-03-19

    Re: Tube/socket contact

    Post by wildiowa on Thu Jan 15, 2015 7:19 pm

    Moving ahead tonight with the suggestions above. It could be a one time event and hope that is the case. Advice is much appreciated.

    kaner

    Posts : 88
    Join date : 2011-09-20

    Re: Tube/socket contact

    Post by kaner on Thu Jan 15, 2015 8:10 pm

    I've used DeOxit to clean tube sockets, but only occasionally. I'd be surprised if it left a residue that made a connection worse, but who knows? I'd do the same with the nut files, and a small blade screwdriver to tighten the sockets, but I'm wondering if there's some other issue? If you open it up, look for any small burn marks, make sure that the leads on the tube sockets have sufficient separation, make sure the solder joints are solid.

    By the way, the wonderful thing about tube amps is that they are very fixable, even if you let the smoke out!

    Kaner

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