Simple, basic Qs about tubes

Discussion in 'Amps and Cabs [BG]' started by adouglas, Jun 30, 2003.

  1. adouglas


    Jun 23, 2003
    Bridgeport, CT
    While doing research for my recent rig upgrade, I read somewhere that tubes are expected to last only one to three years (SWR website, IIRC). Mine is at least seven or eight years old, but I don't play terribly often (I'm not a working musician, just a weekend warrior).

    Is it a good idea to change a preamp tube periodically even if it's still working? Does the tone change or degrade with time? How can you tell if your tube is going bad?

    I was under the impression (for no particular reason) that you use a tube until it dies, then replace it... that's what we used to do with our TV (yes, kids, I'm that old).

    Related questions: What does "microphonic" mean? What's the consensus on the best tube out there?

    Thanks, and apologies if this is all covered in a FAQ someplace. I haven't found one.
  2. Don't sweat it. The people who insist on this the most are the ones with the least amount of facts to back it up. Even though modern tubes are generally not as long lived as their old US counterparts, the difference is that a modern preamp tube will last just fifty years as opposed to NOS 70-80, no joke. Most preamp tubes outlive the amps they're in.

    Unless you just want to waste money, if you're happy with how the amp sounds, if it ain't broke, don't fix it.
    It hums badly, begins to show a white discoloration on the glass, or stops working entirely.
    Your impression is correct. The people who encourage tube replacement are most often tube dealers themselves or others who simply parrot them.
    Vibrations will cause the tube to produce a mechanical sound, like a microphone.

    It depends entirely on what you intend to put it in. A tube that sounds like crap in one amp can sound awesome in another.