How do I know when to change power tubes?

[stonedawn]

Hi all,

I bought my Einstein 100W head used a while ago and therefore have no clue how old the power tubes are. The amp itself was built in 06 and it does have Ruby EL34BHT, which I figure could be the original tubes.

My question would now be, how I can tell if the power tubes need a refresh. Is there any indication in the way the amp sounds?
To my ear it sounds absolutely awesome, but then again I have never heard it with a new set of tubes, so I have not way of comparing

 

[PaulyPanacea]

Usually the tone will fluctuate n not sound as good as it once have. If its not used hard the tubes could still be good. If used hard, i would change....but let your ears be the judge. If you still think it sounds great, dont change em. If it sounds like its lacking...then a nice new set will do ya good!

 

[reussen]

EL34BHTs are Diezel's latest suggestion to use as power tubes, so I guess these are not the tubes that went into your amp in 2006.

That being said: changing tubes is the first thing I do when I buy a used amp. It gives me some sort of comfort to know the tubes are new.

When to change them is not a thing of science (unless one of 'em breaks down, ofcourse.. ). Depending on how often you play your amp, how hot you bias your amp... I change mine about once a year. I know there are lots of guys that hardly ever change them. I guess a good scale would be your hearing. When you notice that your sound is dull or otherwise "different" in a bad way, it might be a good time to change.

EL 34 BHTs or SED EL34s are Diezel's recommendation at present. I rather like the sound of EL34 B-STR tubes. Matter of taste!

Hope this helps.

R.

 

[stonedawn]

Thanks a lot Pauly and Reussen, much appreciated!

 

[Ventura]

Furthermore, tubes that are 'on their way out' will definitely give you indicators of such... Varying volume sweeps, pops and crackles, even physically when looking at them from behind, they may not be illuminated equally. But the slow degeneration of a tube is very hard to notice. It's perceptibly difficult because it's so gradual, you play every day, and every day the microns of internal finish in each tube are eroded/exhausted at a micro level. Sometimes a tube simply GOES!! Pooof!! And you know for sure... But if you feel you're not getting the same gnarl and edge and volume and tone, swap 'em up for a new set. Often when going from old tubes to new tubes of the EXACT same model and manufacturer, you only notice the difference after the swap; this is due to the mention above of the change being so minute, it's difficult to notice unless it's a perfect fail of the tube. Your ears are trained along with the amp as it slowly changes in its tone due to the tubes slowly changing over time...

Peace,
V.

 

[stonedawn]

Thanks a lot V! I was actually always wondering what it is, that gets 'used up' in tubes. Thanks a lot for the insight!

 

[Ventura]

Thanks a lot V! I was actually always wondering what it is, that gets 'used up' in tubes. Thanks a lot for the insight!

Pleasure M'Man... If you do any google searches on vacuum tubes, it'll give you a good rundown on their construction and so forth. The coatings and internal components are what allow for electron exchange and so forth - it's a simple process, but it's a bizarre process all the same. I am amazed with tubes... How they work, how they were ever developed - it's all pretty cool to me.

They're just righteously cool little things

V.