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"Tube life" Anxiety Caused By Using My Amplifier

zastin17

zastin17

Active Member
So something has been really driving me crazy!!

And that is using my Tube Amplfier, and finding myself way overally worrying about the tubes on my Dynaco St-70. (Which I fully restored)

I love the sound, and I love everything about tubes and I'm a bit "emotionally" Obsessed with them and get attached.

But I am having a very hard time just simply enjoying the amp without thinking about every second I use it, (apparently these amazingly georgious tubes inch closer to death.

I don't want to worry about such things while trying too enjoy music. I Just want use it and enjoy it.

I have my Mullard XF3 Blackburns and 7199s Which came with my Dynaco St-70. I love these tubes and think they are absolutely georgious in sounds and looks!!!

And want listen too them, but don't want them to die either..... They are obviously at this point, unobtainable for the unwordly prices they go for.

It's hard for me to get passed that thought while just wanting to listen to music, I want to relax in the music, not stress about its health of the amp.

I have a bucking transformer for it too 115VAC, and always Biased too around 1.42V.

But I have all these tubes, and I think about it in my head and go "So in 10x years all these beautifull tubes will all be garbage?" I can't take that thought that this beautifull amp may destroy itself.

How can I get past this nonsense?!

I do have a couple quads of El34s from Nesstone, and Electroharmonex. Both are great working tubes. Its not like I don't have backups. But that's not the point.

My rectifier is a 5AR4 Matshushida also on the amp when I got it, which apparently may outlast me.

I listen to this amp all the time. Everyday.
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6BL8 work as 6U8 alternatives aswell I found out.
 
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I run a Variac for my Fairchild 260's, and bring the voltage up to 115 V slowly. even though the 5V4g rectifier's come up slowly, i was told a lot of theTube life-use /abuse comes from initial turn on . When long sessions are expected I also use a small fan to keep them cool
 
For some variety, get some reissue tubes and roll them in, just to see how they compare. They're not too expensive, and you may come up with a viable replacement while giving you coveted Blackburns a nice holiday.
 
With the 5ar4 being a controlled warm up tube I think you will have many years of service from your el34's . Just don't plug in a Solid State rectifier .
 
People routinely find these with the original power tubes, which are more likely to be in good shape than the electrolytic caps and the 7199s.
Knew a guy who had an original xf2 equipped unit, which he used every night. It simply ran and ran.
Tubes would likely be fine today, but his house burned down in the Camp Fire.
Check the bias and if that's good you're set.
If you're still worried read a book called getting the most out of vacuum tubes.
It will help you understand how and why tubes fail. The knowledge put my mind at ease.
 
Make sure your coupling caps are in good shape (so you're not putting DC on the grids) and go easy on the bias. Tubes should be good for thousands of hours when operated comfortably within their design limits.

Nothing lasts forever, and that includes you, so relax and enjoy your tubes!
 
I'm listening to my Pilot EL84 amplifier & Pre/Tuner, while the original(Pilot labeled) Mullard 5AR4 sits in a box. I bought a reissue 5AR4 to see if I could hear a difference. All the tubes, including Tungsram EL84's and Mullard 12AX7's, are Pilot labeled and original to the unit. I am eventually going to roll in GE EL84's and other 12AX7's to give the originals a breather. I would be upset if I lost 1 of the originals as they have been together for over 55 years. I wish I could help other than sharing your concerns about losing valuable tubes to usage.

Mark
 
Don't worry so much about what tubes everybody else says are good. Experiment with readily available, affordable tubes.

You may find some that you like, then you can stock up and stop worrying.
 
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Noteworthy that the last St70 I put power tubes in, I got a brand new quad of Mullard from Jim Mcshane for right about a Benjamin delivered.

Yeah right, a boat, bust out another thousand, plus labor.
 
I've found old consol amplifiers with the original tubes that still sounded fine. One, has one of the four output tubes with the flash turned brown. Its getting gassy, but still sounds fine. The only tube you need to worry about if you feel you must worry, would be the 5AR4/GZ34 rectifier tube in a ST-70. Even then, unless you listen at high volumes all the time, its not a problem.
 
That's like being reluctant to drink your beer since, after all, when you have drank it all then it will be gone. And you would then need to get another one.

Tubes often last a good long time, in home hifi amps. A guitarist friend uses a Marshall Plexi with all the knobs on "10." Then he uses a power soak, and then another tube amp not running wide open. He basically uses a Marshall Plexi as a preamp, with the EL34 tubes being pushed to the brink. He has to swap out EL34s pretty regularly because he basically kills them as fast as possible. His tone is to die for. There are other details in his system.

At any rate, in my humble view, when it comes to choosing something to worry about, you have to be judicious. Too many choices. Wearing out vacuum tubes does not rise to the top of my list of things to worry about.
 
If it stresses you out, pop some cheaper tubes into it and enjoy it. It’s easy for me to say because I don’t have expensive tubes to burn, but when those Mullards are gone, they are gone.
However, I’d expect them to last for many years.
It may be a bit like wearing a cheap watch rather than a nice automatic. Personally, I’ll choose the automatic because life is short.
 
Invest in the tubes you need and enjoy.

I have a lifetime supply for the amps and preamps that I use. I don't worry about having to pay through the nose if a tube fails or weakens.

They ain't making NOS tubes anymore, their value can go nowhere but up. I think my investment is secure.
 
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