How long does a 7199 last?

[gnugear]

Does it wear like a normal preamp tube or is it the kind that lasts forever (figuratively speaking).

 

[EC8010]

If you leave it in the box, it will last very well. (Unless there's a faulty seal at the pins.)

Seriously, this is like asking, "How long is a piece of string?" In my experience, if you operate a valve at 1/3 of full dissipation it lasts so long that you don't get to find out its lifetime.

 

[amperex]

I can do better.......

If operated within recommended parameters, about 5000 to 7500 hours for quality NOS.

 

[gnugear]

Thanks ...