When to change vacuum tubes

July 5, 2021
 by Paul McGowan

12 comments on “When to change vacuum tubes”

  1. I presume that tubes degrade *only* with hours used. In that case, it would be good to have the advice in this video stated in terms of hours used, especially since the PS Audio BHK Preamp (which I own) very usefully maintains that counter.

    Would the advice on timing of replacements be the same for preamps and phono stages as for power amps? Might power amps benefit more than preamps or phono stages from swapping tubes at fewer hours?

    The tube complement on my ARC phono stage costs ~$750, so I’m not going to replace it every year, let alone every six months.

    Finally, this video begs the related question: when to swap out the capacitors? I have some vintage equipment, some of which has been in storage for many years.

    1. Good afternoon Sirdodo!I’m gonna take the last question, and answer it first.
      For the vintage equipment, how long have you had it in storage?
      If I knew that, I could give you an accurate answer to that question.
      But generally, unused electrolytic capacitors, have a shelf life, of two to five years.
      If you can, either test the caps, or have a tech to check the caps for you.
      That will tell you baste on the results, if you need to replace them or not.
      Now, to the tubes question.
      Preamps and phono stages, don’t need their tubes replaced that often.
      The tubes that you mite need to replace, are the tubes that do all the heavy lifting.
      These are the tubes, that are in the output session of your power amp.
      All depending on how long you play music on that system, that will predict when you’ll need to replace your power tubes.
      For instance, if you’re playing the system for about 12 hours a day, seven days a week, then it mite be every year, or every two years you may need to replace them.
      But also, keep in mind, some amps are harder on tubes then other amps.

  2. I can’t see to look at things like this, but I have told my sighted wife what to look for.
    Sense we’re talking tubes here, there are quite a few things that’ll signal to you, it’s time to replace your tubes.
    But before I get to that, I’m gonna say this first.
    Paul, if you’re reading this comment, I agree with you, whole heartedly!
    When your tubes are getting ready to go, the sound changes.
    But if you can’t tell just by listening, then start looking.
    If the tube glows red or some other collar, then the tubes are becoming gasy.
    Also, all tubes have these rings either in the top of them, or in the sides of them.
    These rings, are called getters.
    When the tubes are brand new, then the rings are gonna be silver.
    But if those rings turn white, then the tube or tubes have a leaking problem.
    Again, I can’t see to do this.
    But If I could see like I once yoost to be able to, then I would do this.
    If you haven’t got one already, get yourself a good tube tester and test your tubes.
    The tester will tell you, if rather your tubes are still good or not.
    Boy, do I wish they made talking tube testers!
    If I ever had any tubes that were giving me a problem, that would be a sure way to find out which ones are getting ready to go out on me.

  3. Don’t vacuum tubes degrade in a similar way as light bulbs degrade? However as the Centennial light bulb ( https://en.m.wikipedia.org/wiki/Centennial_Light ) shows the life time could be much longer. But the limited life time of light bulbs is also the result of a criminal syndicate of early manufacturers’ agreeing for planned obsolescence. What about a syndicate of vacuum tube manufacturers? Isn’t it a pity: in contrast to vinyl records or magnetic tapes CDs rarely degrade when being played. Thus the only chance in the digital era for keeping turnovers high is to virtually degrade the actual technology by pseudo-innovations rendering actual technology old fashioned and of “poorer” sound quality.

    1. Good afternoon paulsquirrel!
      The question you asked, is square on the head.
      I can remember a time, when you could get 20 or more years out of power tubes.
      But Acores, that was when they were made right here, in North America.
      AKA, right here in the United States.
      But today, most of them are either made in Rusha or China.
      They don’t last as long as the RCA GE and or Sylvania tubes did.
      So in a words, the answer is, both yes and no.
      But the far worst tubes that are on the market today, are the ones that are made in the Check Republic.
      They yoost to be known as Tesla.
      But now, they are known as, JJ Electronic.
      Those tubes will go out on you, quicker then the tubes that are made in Rusha will.

      1. You might be fully right here, John. I cannot remember my father’s and my grandfather’s vacuum tube radio boxes with integrated wide-bander loudspeakers ever requiring new tubes during at least ten years I also used to play with and listening to Schellacks. While the power tubes of my former Einstein vacuum tube OTL mono amps could burn-out after six months.

  4. Tube life varies depending on many factors. If they are NOS then they will last much longer then current production tubes. Preamp. tubes last much longer unless they are run at very high voltage like some manufacturers do. The same applies to output tubes still they have short life span because they are run much harder. Of course tubes like NOS GE 211 output tubes will outlast most any other tube with a life span up to ten year. The sound quality will deteriorate towards the end of the tube’s life span but not as drastically as one might expect. Also keep in mind that tubes require break in time which can be long in many cases so changing tubes every six months or a year makes no sense. One will be changing tubes just when they are coming into their own. The shortest replacement time would be about two years for current production tubes when run hard. Regards.

  5. Just wanted to add something. New tubes have a bright etched quality to their sound reminiscent of bipolar transistor and digital sound. This can be mistaken for good sound by people used to the etched quality. As the tubes break in the sound mellows and now can be misinterpreted as tube aging and time for replacement. Another reason can be that the system has a dip in the frequency response just where the bright, etched frequencies lie and the new tube makes up for that dip in response. Regards.

  6. I have an Audio Research pre-amp; AR recommend changing signal tubes after 4000 hours of use and power tubes after 2000 hours. So for my level of usage, I change the 6550C tubes in the power supply every year and the signal tubes (6H30P) every 2 years to keep within AR’s suggested parameters.
    I certainly notice the difference when the tubes are changed; clarity and ‘speed’ both improve markedly. However, the cost of changing all the tubes is very expensive but necessary!
    Another issue is the make of tube and the need for matching (or otherwise) – a whole new topic……..

    1. Good morning Snufkin!
      Are you buying those tubes directly from Audio Research?
      I’m asking because, if you are, then that’s why they’re costing you too much money.
      You can get those same tubes from other tube vendors and not worry about braking the bank.
      If I need to get replacement tubes for anything, I get them from two places.
      The first place that I could suggest to you, is Tube Depot.
      Their URL is:
      The second place that I can also suggest to you, is Antique Electronics Supply.
      Their URL is:
      I haven’t done business with these guise as of yet, but I hear they’re excellent in what they do.
      But here is a third suggestion for you.
      The Tube Store.
      Their URL is:
      I hope this helps you save money on tubes.

  7. Hi John – thanks for the links.
    I did find out how much AR wanted for tubes and was quite shocked…….
    I live in Scotland and have to therefore go through Absolute Sounds in London for official AR spares. They wanted £777 for the pre-amp tubes and £410 for the power supply!! For the power supply, which has 2 x 6550 and 2 x 6H30P that would be an average of over £100 ($140) each…..
    Instead I bought a complete set (including matching) of 10x Electroharmonix Gold Pin 6H30P and 2x Sovtek 6550 from the Hi-Fi Collective, where I buy most of my components, for a grand total of £466 ($648) rather than the £1,187 ($1,650) that Absolute Sounds wanted. Still not cheap but saved myself $1,000!!


  8. Talking about replacing tubes reminds me of a story I heard some years ago ,an old army base that had been mothballed for about eighteen years was due to be reopened, the crew who moved in to reactivate the base found an H+H British amplifier that provided music in the NAAFI had not been switched off when the base was shut down and it was still working perfectly. Would a tube amp still work after all those years passing white noise through the speakers.

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