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
I just put some new EH 6SN7 in my Supratek pre and they sound great. There is no need to spend a ton of money on expensive tubes IMO.
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.