Changing preamp tubes

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Bishop5150

Bishop5150

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I'm going to replace my preamp tubes in my 5150 III today. I had a question about swapping tubes. I've always heard that it's best to wear gloves or something when handling tubes so you don't get the oils from your skin on the tubes. I always do this but is it true or BS? :confused:
 
Preamp tubes...not as much as powertubes....but I usually pull them with my fingers...then wipe them off with a paper towel.
 
I used to use a sock or something for power tubes, or a cloth, or use the paper that stuff came in... (this is the worst idea) First off, I think it's much riskier to use the sock/cloth/paper simply because theres a chance a piece of it can get stuck on the pin and go into the socket and THIS is not a good thing, anything flammable going between two metal contacts.

Just make sure your not sweaty and your hands are clean I've changed a lot of power tubes this way with out issue, also pre amp tubes I've never ever had a problem just changing with my bare fingers.

I know it sounds silly, but the reality is with all the warnings and stupid shit you read on some of these websites as precautionary measures, the truth is it makes you so damn nervous your more likely to mess it up from being concerned about doing something stupid. Just make sure the pins are lined up with the holes before you push down, and always wiggle gently, you never want to use pressure otherwise you'll end up with a bent pin socket and that sucks.

I swear a lot of this stuff is made up so people can sell shitty tubes and have something to blame it on when it blows up...

*Oh no you mean you didn't clean your sockets with our special holy blessed contact cleaner, and you mean you weren't in a dust free hermetically sealed room oh that's why the tubes failed, oh your air temperature was above 76 degrees F, you sir DO not get a refund!* (Obviously I'm blowing this a bit out of proportion but it's not that far off sometimes from personal experience...)
 
I would think the only reason to wear gloves when swapping is if you were playing it and trying to do swaps on the fly and not waiting for it to cool down completely. I never heard of the oil skin thing before reading this thread, I just use my fingers. I'm assuming at the temperature the tubes run at it won't really make a difference, probably just burn off anything.
 
I have read the 'oil on glass' thing with tubes in a few commentaries and web sites, but have not had any problems with premature tube failure using just my hands thus far. (I'm really asking for it with that statement...) Handling halogen bulbs with bare hands causing early failure, yes, that is pretty much proven. Vacuum tubes? I've really only seen that claim recently, and not much to fully support it.
 
Thanks fellas. I heard it years ago so I've done it ever since. But never heard the definitive word about it.
 
I wouldn't worry about the oil.

However,

I usually use a rag or something if they're hot. :rock:
 
Yea sorry if I didn't state the obvious to me, I don't fuck with tubes when they are hot, let them cool off... lol. Pre amp tubes I suppose you can get away with swapping them while warm, but yea I just assume wait a little bit and change them around, if your swapping and stuff, amp shouldn't be on long enough for the pre amp tubes to really get that hot, plus I've never noticed pres to get that hot in general...
 
So I got my new pre amp tubes in today for my 5150 III. It had all JJ's in it when I got it used about a year ago. Pretty sure they were the stock tubes. Anyway, I've heard several guys talk about how the earlier ones came with a mix of (2)Sovtek 12AX7WC for slots V1 and V4 and (4)Electro-Harmonix 12AX7EH for slots V2,V3 and V5,V6 and Sovtek 12AX7LPS for slots V7 and V8 for the Effects loop and Phase Inverter. Well the Sovtek 12AX7LPS are a little fatter than the other Sovteks or my JJ's and won't slide all the way down because of the metal ring around the tube socket. It is almost flush but not quite. I didn't want to force the issue so I put my JJ's back in the V7 and V8 slots for now. Is it ok to have the tubes not completely in the socket? Should I try to widen the metal ring around the tube socket so they will slide all the way in or should I just go with a different tube thats not quite so fat at the base? :confused:
 
victim5150":th1p113q said:
So I got my new pre amp tubes in today for my 5150 III. It had all JJ's in it when I got it used about a year ago. Pretty sure they were the stock tubes. Anyway, I've heard several guys talk about how the earlier ones came with a mix of (2)Sovtek 12AX7WC for slots V1 and V4 and (4)Electro-Harmonix 12AX7EH for slots V2,V3 and V5,V6 and Sovtek 12AX7LPS for slots V7 and V8 for the Effects loop and Phase Inverter. Well the Sovtek 12AX7LPS are a little fatter than the other Sovteks or my JJ's and won't slide all the way down because of the metal ring around the tube socket. It is almost flush but not quite. I didn't want to force the issue so I put my JJ's back in the V7 and V8 slots for now. Is it ok to have the tubes not completely in the socket? Should I try to widen the metal ring around the tube socket so they will slide all the way in or should I just go with a different tube thats not quite so fat at the base? :confused:
Click to expand...

Beyond me man I Have NEVER EVER had this issue before... :confused:
 
I got them to go all the way into the socket. It's just a pretty tight squeeze because those two tubes are a little fatter than most 12Ax7's and thay are snug inside the ring surrounding the socket. I just had to push a little harder. I was hesitant at first for fear of cracking the tubes but it's all good now. Amp sounds great with new tubes instead of the JJ's that we're in it. Power tubes will be next after my band gets back from our Indy gig next weekend.
 
I get an old yellow rag and use that to pull tubes, you shouldn't be taking the tubes out when they're hot anyway.. preamp tubes cool faster by the way.

I don't think it is BS, the tech I see told me about it, and he's been doing this shit for about 25 years I think. It's not something you need to go massively out of your way to do to be honest. Better safe than wallet light.
 
I don't think it really matters for tubes.... I've heard this a lot though. I know this is the case with car headlight bulbs... but those are just a tid bit different. ;)
 
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