How do I know when a tube is done for?

[MightyPOOsticK]

I just got my silvertone back from the guitar shop...woo!

I was wondering how I can tell when a tube is done for in the amp?

Thanks!

 

[teknomike]

Sometmes they fart.

My Vibrosonic reverb used to do that when the 6L6's were on their last legs. Kind of a THHHHHPPPPPTTTT....

YMMV

mike

 

[Bass Freak]

when you gotta turn it all the way up to hear just the weeee littlest bit


freak

 

[grinder]

My Carvin head will start to feed back uncontrolably and keep going even after I turn off the guitar volume.

 

[Toker41]

I find it best to just change the tubes in my boogie every 6 months. I have had tubes that were tested and I was told they still had 90% of thier life left, however I replaced them anyway and it was a world of difference. Tubes are cheap, and if one goes while playing out....it goes and your screwed. Back when I didn't know tone and played thru a Peavey VTM60 (I know, I know....crap!) the amp sounded fine (as fine as a Peavey can), but it blew a fuse in the middle of a set, and blew ever fuse I put in untill I finally replaced the tubes. Didn't notice any change in the tone, though....still sounded like a crappy Peavey.

 

[sjcrts]

I'd know if a tube was going bad when I got a small metalic "ping"
sound from my Marshall.

 

[bongolation]

Well, if all else fails, you could actually TEST it.

The average public-access tester may not be that well calibrated, but comparing the readings to a known good tube of the same type will give you an idea, and any really dying tube will show up as such even on a funky tester.