How do I know If I need new tubes?

[Dills]

Hi there, i am running a peavey classic 50 and i havent changed the tubes in it in ages , how would i be able to tell, the lead channel is very good it is just slightly harsh in the high end, and the mids are quite "spiky" if thats the correct word, would changing the tubes help this at all?

Also those that use one how do u set your tone controls since they all go to 12.

 

[Edgecrusher]

Re: How do I know If I need new tubes?

Generally tubes need to be changed when you can hear the amp isnt as loud as it was or its getting mushy and flubby sounding. My suggestion is always to buy a back up set to have just incase something fails. Then if you suspect they are going out pop in the back up set and see if the sound changes if not put the others back in and save your backups for another day. Either way its good to have spares on hand and where your amp uses EL84's for power you shouldnt have to rebias it should be a plug and play deal. Your spikey mids and such could be influenced by the tubes I'm not real familiar with the classic 50 so I wont go out on a limb and say definately.

 

[Gamera]

Re: How do I know If I need new tubes?

My suggestion is always to buy a back up set to have just incase something fails.

Do tubes have a shelf-life? That is to say, if you had an extra set laying around forever would they eventually go bad...like batteries? Or do they only go bad after use...like lightbulbs? Just curoius.

Actually I have a feeling I just answered my own question with that lightbulb analogy...since they're of a similar design.

 

[Edgecrusher]

Re: How do I know If I need new tubes?

Do tubes have a shelf-life? That is to say, if you had an extra set laying around forever would they eventually go bad...like batteries? Or do they only go bad after use...like lightbulbs? Just curoius.

Actually I have a feeling I just answered my own question with that lightbulb analogy...since they're of a similar design.

As long as they dont get bumped, broken or the gas leaks, they will last forever. I have some tung-sol tubes that are 1950's vintage and just as good as the day they were made.