2. misc-audio
  3. 982899790

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...
cwlondon
detlof
1,899 posts
 
Musicslug, true what you say, but then there is also tube aging with its slow and gentle deterioration, which is indeed hardly noticable. Generally you only realise the need for change when you have indeed done so. That's what's bugging us. So right you are, all the more there is need for a tube tester. Not for compulsion neurotics though, because they might test tubes more than using them for enjoyment. All the same: Anyone got an idea of a reliable source for them ? (t.testers..not c.neurotics)
rcprince
3,074 posts
 
I'll add that I've had the same Telefunkens in my JP80 for almost 3 years, and usually leave it on 24 hours a day from Wednesday or Thursday through Monday (it used to be just for the weekend, but that's been expanding). Last time Andy Bouwman made a check on these tubes after 1-1/2 years they were all hardly changed from when I first bought them. The exception, and not applicable to the JPL, are the two 6DJ8s for the MC stage, which go bad after a year or two; the JP80 pushes those tubes to the limit, I guess. George Kaye here in NYC made a small signal tube tester a number of years ago that sold in the $500 range--I don't know if it's still available. And Detlof, I think we all know a reliable source for neurotics....
garfish
1,840 posts
 
Hi Cw; I have a Sonic Frontiers Line 2 with 6 Sovtek 6922 tubes. I typically listen 4-5 hours/day, and also broke in some equipment using the Line 2-- leave it in standby the rest of the time. After about 16-18 months, my system gradually was sounding brighter, harder, and distinctly more fatiguing. It finally got to the point where I could hardly stand to listen to it. Then it finally dawned on me that I had NEVER changed my pre-amp tubes. Duh! After installing a new set of stock Sovteks-- Viola', the music came back. I had thousands of hours on those tubes, and really learned a valuable lesson. I now replace them about every 12-14 months. Cheers. Craig.
detlof
1,899 posts
 
Hi Garfish, this is just a guess, but I think its probably the Sovtecs and not the SF. My experience has been, that Sovtecs seem to age rather quickly with exactly the sound-effects, which you describe and this not only in the Jadis, but also in the Beveridges of yore, a wonderful design by Roger Modjeski, which was killed and driven off the market by a hatchet review of H.Pearson in favour of the ARC SP8, in the SP 11 and 12.
gregm
3,409 posts
 
Craig, Detlof's probably hit it the proverbial nail on the SOVhead. The current supply on (my) Jadis was quite stable and ample, hence no extraordinary tube wear. But replacement every 12??? That's expensive -- why not try another tube manuf. and if you feel the top end is soft by comparison -- don't worry: this could be cable or the machine... Just an idea.
More to discover