Wolfbane Posted March 1, 2016 Share Posted March 1, 2016 I keep a daily log of the use of my tube amp(s) in MS Excel to ensure I know when to re-test tubes, etc.. Am I alone or do others do this? Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted March 1, 2016 Share Posted March 1, 2016 You might be on an island with that. I just troubleshoot/swap when I hear a degrading audio condition. Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted March 1, 2016 Share Posted March 1, 2016 I don't keep a daily log of use, but I keep a log of the tubes I have and whether I've tested them, and the results. 1 Quote Link to comment Share on other sites More sharing options...
Wolfbane Posted March 1, 2016 Author Share Posted March 1, 2016 I see no palm trees, no fancy mixed drinks with umbrellas, no bikinis and the place looks like my family room. But I do know when I last set the bias on my Fisher X-202 and the date/hours ago when I replaced the original 7189's. Quote Link to comment Share on other sites More sharing options...
muel Posted March 1, 2016 Share Posted March 1, 2016 I keep an inventory list to track what tubes I install and when so I have an idea of the number of hours used. I've heard some people say that power tubes gradually decline in sound quality so I will sometimes swap for a new quad to compare. So far I have never heard any difference that I would call "degradation." My testers don't tell me much more than whether there is a short. They provide a "quality" result that doesn't seem to mean much. I think also keeping a log of anything you change on your system is a good idea. I include notes about my impressions of the change as well. Quote Link to comment Share on other sites More sharing options...
JJkizak Posted March 1, 2016 Share Posted March 1, 2016 In the old days we would remove the old tubes, throw them away and insert new tubes. Done deal. JJK Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted March 1, 2016 Share Posted March 1, 2016 I keep a daily log of the use of my tube amp(s) in MS Excel to ensure I know when to re-test tubes, etc.. Am I alone or do others do this? Not at all! To me, the only possible use for such information is if your amp uses very costly, and hard to obtain, NOS tubes in which case a prospective buyer may be curious about the number of hours logged. And that may not mean anything if the tubes are not correctly biased, or properly ventilated. Looking at what the output tubes show in a tester is worthless as the only way to know about their performance is to evaluate them in the circuit in which they are used (unless you have access to a curve tracer which can provide some very useful info). Small signal tubes, such as those used for voltage amplification, degrade so slowly (if at all) that testing them is usually not worth the bother unless they get very noisy or microphonic (and neither of those conditions can be demonstrated with a tester). With push-pull amps, I recommend rechecking the bias when new output tubes are installed, doing it again at 50-100 hours, and then maybe annually regardless of the number of hours of use. If the system sounds good what's the difference how many hours the tubes have on them? Maynard Quote Link to comment Share on other sites More sharing options...
Wolfbane Posted March 1, 2016 Author Share Posted March 1, 2016 In the old days we would remove the old tubes, throw them away and insert new tubes. Done deal. JJK You do that now and someone will catch them in mid-air label them 'NOS' and hawk them as 'special' on Epay. Things have changed even though the demand for tubes has dropped to a fraction of what it once was. I'ts getting to the point where I may decide to just trade any spare tubes I have for other tubes. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 2, 2016 Share Posted March 2, 2016 (edited) I keep a daily log of the use of my tube amp(s) in MS Excel to ensure I know when to re-test tubes, etc.. Am I alone or do others do this? Not at all! To me, the only possible use for such information is if your amp uses very costly, and hard to obtain, NOS tubes in which case a prospective buyer may be curious about the number of hours logged. And that may not mean anything if the tubes are not correctly biased, or properly ventilated. Looking at what the output tubes show in a tester is worthless as the only way to know about their performance is to evaluate them in the circuit in which they are used (unless you have access to a curve tracer which can provide some very useful info). Small signal tubes, such as those used for voltage amplification, degrade so slowly (if at all) that testing them is usually not worth the bother unless they get very noisy or microphonic (and neither of those conditions can be demonstrated with a tester). With push-pull amps, I recommend rechecking the bias when new output tubes are installed, doing it again at 50-100 hours, and then maybe annually regardless of the number of hours of use. If the system sounds good what's the difference how many hours the tubes have on them?Maynard Spot on advice except if equipped with test points i'd check the bias every 3 to 6 months depending on how heavy a user. The bias will tell you everything about an output tubes health. If one tube constantly need adjustment to equal the others its unstable and should be replaced. If all the output tubes have thousands of hours on them I'd just replace them all. Edited March 2, 2016 by NOSValves Quote Link to comment Share on other sites More sharing options...
jwc Posted March 2, 2016 Share Posted March 2, 2016 Naw. Burn till they screw up/malfunction/buzz...... If spend lots of time worried about it....buy cheaper tubes or just don't do tubes. 1 Quote Link to comment Share on other sites More sharing options...
ClaudeJ1 Posted March 2, 2016 Share Posted March 2, 2016 (edited) Naw. Burn till they screw up/malfunction/buzz...... If spend lots of time worried about it....buy cheaper tubes or just don't do tubes. I had McIntosh 240, Marantz 8B, Scott, HK Citation II, in my 20's. They all sounded better than SS back then..............then came Dr. Matti Otala (with his AES paper on Transient Intermodulation Distortion) who found the reason why SS sounded bad.......because we were measuring the wrong things. So the entire world fixed all the SS issues and made them sound good. Tubes sound absolutely wondertul with their wonderfully pleasant even order harmonics "sweetness." But SS is more neutral and hassle free except for replacing Electrolytic capacitors after 30 years....................................so, I gave up all the tube wear and maintenance hassles decades ago. Even Paul Klipsch said SS was superior to tubes, and gave Otala full credit for changing the industry. BUT for those who love the tube sound, I'm amazed that the devices are still available which was my fear when I got into SS amps. Now I think the switching amps from NAD, Hypex, Audio Research and others are the top dogs in the sound department. Neutral, powerful, maintenance free, and can drive any speaker load without all the impance varation anomalies of tubes. Either way, it's all good on HORNS!! Edited March 2, 2016 by ClaudeJ1 Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 4, 2016 Share Posted March 4, 2016 Yup SS can be very good problem is to get in the same ball park as a nice tube amp you have to drop about double the cash IMHO Quote Link to comment Share on other sites More sharing options...
Thaddeus Smith Posted March 4, 2016 Share Posted March 4, 2016 my amp uses $4 tubes, so no I do not. I think I may stock up on a few spares just to have for that "some day" event when they finally wear out and the tubes are NLA, otherwise Maynard thinks I shouldn't have to worry about them in my lifetime. Quote Link to comment Share on other sites More sharing options...
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