Tube Durablity

RLeahey14 · Post by **RLeahey14** » Thursday Mar 06, 2008

I know this may sound stupid but I had an exchange set of tubes that I had it my bookbag when walking from class last month my bag ripped open. I later found out that one of the tubes I had was missing. I had kept the matching one just so I had an extra one when my friend called me yesterday saying that he found my tube. It was buried in the snow and since it melted he said it was sitting on the sidewalk. Now there doesn't look like anything wrong with it and I was wondering if you thought this might still work, and if I do try it is there any harm that may be done to my amp?

this is a small preamp tube.. not sure of the brand or whatever.. it came extra with my preamp.. NOT a power tube.. don't know if this makes a difference

onetooloud · Post by **onetooloud** » Thursday Mar 06, 2008

I feel its probably fine. If there was a short inside caused by its being dropped it could cause a problem but I still feel that its remote.

If the glass wasn't broken it didn't hit hard.

Find a tube tester and test it that will rule out a short. Thats a very basic test that even the cheapest tester should find with ease.

With a vacum tube manual in a pinch you could test it for shorts with a multimeter. If you'd like I could supply internal pin connections so you could test with a meter.

Its possible for the filament or heater to have broken in which case it wouldn't work at all.

The water wouldn't cause a problem unless the envelope was broken.

If your in the Johnstown area I have several testers one of which is the cadillac of tube testers. I'd be happy to test it for you.

I still feel its fine.

onegunguitar · Post by **onegunguitar** » Thursday Mar 06, 2008

You don't need to have "matching"preamp tubes,only power tubes need to be matched and biased. If I were you I'd throw it out and buy a new one,they are only 12-15 bucks apiece. Moisture may have ruined the tube or help shorten it's life, plus handling tubes with bare hands will shorten tube life as well.

lonewolf · Post by **lonewolf** » Friday Mar 07, 2008

onegunguitar wrote:plus handling tubes with bare hands will shorten tube life as well.

This is true, but it can be fixed with a good windex cleaning. The problem is caused by body "oil" smudges that heat up on the glass surface and also act as a heat insulator and don't allow the tube heat to dissipate as well.

Barring a broken internal part, the physical characteristics of these tubes shouldn't change.

I would give them a good windex cleaning (no streaks left) and try them out.

RLeahey14 · Post by **RLeahey14** » Friday Mar 07, 2008

Thank you for your help, I'm new to using amps so I have no idea, and yeah they were just back up tubes for my preamp, its a Mesa Mod and its really too much trouble to take it all apart to see if it works.

DrumAndDestroy · Post by **DrumAndDestroy** » Friday Mar 07, 2008

onegunguitar wrote:plus handling tubes with bare hands will shorten tube life as well.

never knew that

metalchurch · Post by **metalchurch** » Friday Mar 07, 2008

I wear latex gloves when handling my tube. I have noticed a dramatic difference in durability, longevity, and hardness.
And as mentioned above it will keep finger prints and smudges off of the tube.

I'm pretty much on the safe side when it comes to handling my tube, cause I don't even trust where it's been.

hahaha

RLeahey14 · Post by **RLeahey14** » Monday Mar 10, 2008

yeah i like to be safe when handling my tube, or letting someone else handle it because there is always a chance that it might blow early