Tubes dying.. how do you know?

[cheezemaster]

Just a general (stupid?) question.

How do you know when your tubes need to be replaced?

I was playing thru my Blues Jr. the other day at band practice an it just sounded.. odd... Low end just seemed mushy and mids were wimpy. I'm thinking the tubes might be going... they've been in there for at least a couple years.

[marvar]

Re: Tubes dying.. how do you know?

If your power tubes are a couple of years old- and you use your amp regularly, yes you should replace them. Pre amp tubes usually last several years- but it wouldn't be a bad idea to replace them all- for reliability if nothing else.

[GuitarStv]

Re: Tubes dying.. how do you know?

I've had people tell me that tubes sound better with age . . . and I've also had people tell me that you should change them every few months . . . I figure if they sound funny to you, they're probably ready to go

[Zhangliqun]

Re: Tubes dying.. how do you know?

Power tubes I assume? Yes, when they lose their punch and you start having to crank up the volume to get it where it used to be and even that still isn't enough, it's definitely time for new power tubes.

But don't just grab some new ones and pop them in. They have to be a matched pair (or quartet, depending on how many power tubes your amp uses). The amp needs to be rebiased and if you don't know how to do that, you need to take it to the shop.

[some_dude]

Re: Tubes dying.. how do you know?

When my power tubes start to go the bass sounds mushy and undefined, it looses all it's top end harmonics, and it's treble and midrange go south (huge volume loss).

[CapoFirstFret]

Re: Tubes dying.. how do you know?

yeah, all of the above...it's usually fairly obvious when tubes start going out...low end all but disappears or turns to complete mush...also clean headroom goes out the window and you start distorting at really low volumes, and we're not talking pleasant distortion..we're talking nasty, messy, unusable distortion. If it's sounding funny to you, tubes are the prime candidate

[Hoss]

Re: Tubes dying.. how do you know?

hmmm...that's funny the lows in my Jr yesterday started becoming pretty flubby and there's starting to be a bit of volume loss...there has to be something wrong because i had a great clean sound dialed in the other day and now that sound is just flubby...especially when i play the top two strings.

if i put the exact same brand of tubes in there would i need to rebias it?

[Zerberus]

Re: Tubes dying.. how do you know?

I´m with Zhang and Daisy... flabby and undefined, but also "dull" tones are the first sign of powertube failure.

[marvar]

Re: Tubes dying.. how do you know?

Using the same brand of tube doesn't mean that they are the same RATING- to keep from a rebias, the replacement tubes must be of the the same value rating wise- example- Groove tubes #5, or in the case of Mesa- the color.