six year old 6sn7's, pushing my luck?


I retubed my Cary SLP-05 with Pope tubes about 5 years ago. I leave the preamp on pretty much all the time except when I go on vacation. That comes to about....45,000 hours. The tubes are supposed to be good for 10,000.

And...I've experienced no noticeable degradation in the sound. I heard a clicking sound once when I turned the system on after a week's time off, but I jiggled the offending tube and the sound stopped.

I've experienced tube failure and noise and rush in other systems, but this one seems to be the Energizer Bunny of tubesets.

I wish those Pope tubes were still available for a reasonable price, but Upscale now wants $275 per tube, and I need 6 -- I just cant justify 1650 to retube the preamp, but for now maybe I don't need to.

Any thoughts on this? Have you had tubes that lasted like this? Could they be degrading so slowly that I don't notice? Am I taking any chances with my equipment?

Thanks much and happy new year!

Rich
rbirke
If you throw a frog in hot water; it will try to escape immediately. Raise the temp, a degree at a time, over an extended period; it will complacently remain, and boil to death(in agreement with Tubegroover). Get some NOS tubes, try them, and I'll bet there is a marked improvement. If not: you haven't lost anything! They will be put into service eventually. I've a stock of TungSol round plates, Sylvania tall bottle Ws, Sylvania and Ken-Rad 6SN7GTs for that day. Forget about newly manufactured tubes. Even your old Popes will sound better.
Rodman - have you tried Black Treasures? They are new but were meant to sound like NOS tubes. The new Psvane may not be as "NOS"y but they are meant to be a major step above EH and other commodity tubes.

I really hope that some new quality tubes (e.g. Psvane) continue to show up. If we are relying on NOS tubes in 20 years some of the magic will be lost.
Rodman - I take that as a political, not audiophile, statement. Your choice. Happy listening.
I suppose, if you consider the total lack of quality, intrinsic in virtually every product that comes out of that part of the World, a political issue; that's your choice. There are too many alternatives, with which to please my ears.