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!


Showing 4 responses by rodman99999

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.
Mr D- Absolutely NOT interested in anything from China! 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.
Mr T- My Cary monoblocks use 6SN7s as phase splitters & drivers. I tried the top ten 6SN7GT/VT231's(all bottom gettered, but for the Sylvania 'W' tall bottles, from the 40's), mentioned on the Chimera list( in them, the first year of ownership(2002). I found the cleanest, most liquid, least tubey(to me=unnaturally warm) and most extended(both directions), to be the four that I mentioned as having in reserve. The Sylvania and Ken-Rad VT231/6SN7GTs only seem to give up a bit of sound stage width & depth, to the TS's and 'W's. That's using mixed pairs, in the mentioned positions. I tried every possible combination, in that year.