Huge Tube Glow - Problem?

My 12AU7 Bugle Boys started doing something funky. When I first turn on my Rogue Perseus tube pre, a couple of tubes let off a huge flame or glow (not sure what to call it but it gets bright in there) for a second and then settle down. Is this a sign of the tubes going bad or is it a normal thing?

Comments

  • F1nut
    F1nut Posts: 50,564
    It's called tube flash, which is not unusual for some signal tubes. Are you sure they just started doing it?
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • heiney9
    heiney9 Posts: 25,165
    Perfectly normal for Euro tubes of that type. In fact that's one more clue they are genuine. I know you were worried they might be fakes when you got them. Not all "flash" like that, but many Euro signal tubes do. Not a single thing to worry about unless it looks like fireworks inside the tube....lol

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
  • george daniel
    george daniel Posts: 12,096
    The flash is your European friend
    JC approves....he told me so. (F-1 nut)
  • audiocr381ve
    audiocr381ve Posts: 2,588
    Haha great news. Thanks guys!

    Jesse, I noticed it happening about a week ago. Maybe they have been doing it all along? I'm just happy it's sounding so good. No worries here :)

    Brock, the Pass Aleph 30 sounds wonderful.
  • F1nut
    F1nut Posts: 50,564
    Maybe they have been doing it all along?

    Yes I think so as it would be highly unusual otherwise.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • Dawgfish
    Dawgfish Posts: 2,554
    Yep that's very characteristic of Mullards and Amperex's. Good sign.