Stupid vintage tube maintenance dilemma: guru's only please

96tbird · #1 08-17-2011, 01:16 PM

I've had my V4b for 20+ years and figured I should clean the pre tubes. So I pulled them and the glass is coated with appears to be mostly nicotine, from the bad old days when we could smoke in bars here in the great white north. I rubbed a 12 AX7 a little with my finger and off it came with the Nice AMPEREX lettering.

I tested a Sylvania 12DW7 in the same way with the same results.

I should clean them for heat dissipation but they will in effect become UNLABELED and unidentifiable if they survive after my demise. These are sweet vintage tubes. What to do?

nashvillebill · #2 08-17-2011, 02:07 PM

Label them with a magic marker, or white-out, or white paint with a tiny brush.

I've read the theory that tube manufacturers intentionally make the lettering easy to rub off, so people won't clean tubes and try to sell them as new. Dunno if I buy into that, maybe the manufacturers just used the cheapest lettering they can get away with.

Bottom line, don't bother cleaning tubes.

Farfetched · #3 08-17-2011, 02:10 PM

lol i did that with a MULLARD. good thing i stopped before i rubbed out the made in great britain part.

BurningSkies · #4 08-17-2011, 02:12 PM

A fine black permanent marker would work fine...but don't use white out. too thick and goopy.

96tbird · #5 08-17-2011, 03:30 PM

Thanks, OT I just won an NOS Mullard 12au7 for 23 bucks to my door. Now to find deals on 2 12ax7's and a 12DW7. I'll roll them in and see how they sound. Nothing wrong with what's in there though.

chicago_mike · #6 08-17-2011, 03:38 PM

Careful with what you clean them with.

some chemicals dont wipe off easily, like finger grease and can prematurely kill the tube. the oils will soften the glass as it heats up and poof...bad tube.

dry cloth.

BassmanPaul · #7 08-17-2011, 03:47 PM

Quote:

Originally Posted by chicago_mike

Careful with what you clean them with.

some chemicals dont wipe off easily, like finger grease and can prematurely kill the tube. the oils will soften the glass as it heats up and poof...bad tube.

dry cloth.

Sorry Mike fingerprints will do no damage whatsoever to a pre-amp tube. not even to an output tube. They are not halogen lamps y'know.

BurningSkies · #8 08-17-2011, 03:52 PM

Quote:

Originally Posted by BassmanPaul

Sorry Mike fingerprints will do no damage whatsoever to a pre-amp tube. not even to an output tube. They are not halogen lamps y'know.

If it's that hot, you'll want your amp to head to the tech...you've got bigger problems.