Detlof Check out e-bay for tube testers. My audio buddy just bought one from a guy that restores and calibrates them. This past Sunday we went through about a quarter of my stash. What is most amazing to me is how the old tubes fared against the sovteks and newer tubes, all were MUCHO stronger. I have a bunch of amperex and the old Bugle Boy's and some Telefunkens, RCA's and Sylvanias. Only one of the old tubes was shorted. Two of them buried the meter! A few of these tubes were in my McIntosh MC-60's dating back to the mid 50's!! I also found out that the Svetlana 6550 output tubes I installed in my amp a year ago still tested strong with plenty of life. I estimate that they have about 1200 hours based on my use. It is a nice thing to know and you can keep your equipment running optimally. I say at the cost of tubes these days a tester is indispensible. I plan on purchasing one in the near future.
New tubes every year...or every five? ?
I may get thrown off this forum, referred to an ear specialist and sent to Circuit City to replace my system, but it recently occured to me that I did not change the tubes in my recently dumped Jadis JPL pre amp for 5 years! There is no on/off switch on this pre amp but there is a "stand by" switch which was always on. I would say I listened to the system for only an hour or so a week. Since trading my Apogee stages for Martin Logan SL3's about 3 years ago, I rarely listened to the system and found it uninvolving and a little fatiguing and bright. It didn't necessarily sound bad -- I thought I just needed to buy a new D/A or go back to LPs. Is it possible that my very light use and the standby switch would give the tubes such a long lifespan or would a change of tubes have dramatically improved the sound? Maybe I should have kept the system?!? Oh well, more fun to buy new stuff...