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How do you know when a tube is going out?

62strat62strat Posts: 638
edited January 2004 in Musicians and Gearheads
K, more problems obvioulsy...fuck...

huge gig coming up on saturday...dont know if i can bring my amp in at all this week because im at work... so what do i do?

i was rehearsing, and every once in awhile..the amp would cut out, not completely..but start..uh..well, the singal became really weak...kidn of madea fuzzing noise, crackling noise...someteims id tap on it or knock it and it would be alright again..other times it would just start working again, now when it does this..it still does work but sounds like some crackling goingon...god this doesnt make sense, tubes going out? or loose connection inside somewhere? and do i attempt to play with it at our show this weekend?

damn fender tube amps
Post edited by Unknown User on

Comments

  • HoorayForHumansHoorayForHumans Posts: 151
    the exact same thing used to happen to my prosonic.. it doesn't do that anymore.. i have no idea what it was.
    this heart's on fire
  • thelouderthebetterthelouderthebetter Posts: 57
    It might be a bad preamp tube.
    I was/am a bass player and I used to blow up my friends' amps all the time!

    I had an giant ampeg svt, and usually it was bad preamp tubes when it made that noise. I didn't change them myself though, but i think it's easy. Don't play it though. I did that once, and my amp caught on fire in CBGB's and the show was over!
    Smile :)
  • mccreadyisgodmccreadyisgod Bumfuq, MT Posts: 6,395
    Yeah, sounds like a preamp tube to me...

    A connection might be to blame, though.

    Has it been a while since you re-tubed? If so, go ahead and do it anyways... if the problem isn't fixed, take it to a techie who can doctor it to health. You might make sure the tubes (all of them, power tubes and if it has one, rectifier) are well-seated in their sockets.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    MIG do you still know the link to Sal Trentino's Amp Page?

    I think you guys are right. its a preamp tube shorting or something like that. You could power it up and turn it around look for a red glow on the plates in the tubes.

    Basically you need to get that thing looked at before the gig it could cause a fire then you'd be without an amp. If worse comes to worse and they can't fix it in time you might look to rent a hot rod from someone or something else you can get in a fix. I know it sucks but you don't want the gig to go up in smoke either. It's probably a minor problem right now so don't worry too much.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • Pacomc79Pacomc79 Posts: 9,404
    62. Read this. It should help.


    http://trentino.best.vwh.net/
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • who's_pearljam?who's_pearljam? Posts: 2,104
    Originally posted by thelouderthebetter
    It might be a bad preamp tube.
    I was/am a bass player and I used to blow up my friends' amps all the time!

    I had an giant ampeg svt, and usually it was bad preamp tubes when it made that noise. I didn't change them myself though, but i think it's easy. Don't play it though. I did that once, and my amp caught on fire in CBGB's and the show was over!

    How can't you love this girl! Spoken like a true rocker!
    I was there at CBGB"s when it went. Why do you think her name is louderthebetter!

    When she blew up one of mine, it was a little more!

    but usually, that sound is one of the little preamp tubes. Usually minor stuff, but don't use it on stage until you know. When you play out with amps, they take more abuse, so they are higher maintenance as usually, tubes loosen or dirt ges in the knobs.
    Quick and dirty, sometimes you can gently tap the tubes when the amp is on,with a pencil or something and pinpoint the loose one or bad one.
    Like Paco says, borrow an amp if you can't fix it this week.

    And, Have a good gig.
    Fender tube amps are great by the way. All tube amps will dio this at somepoint.
    Be kind, man
    Don't be mankind. ~Captain Beefheart
    __________________________________
  • JSP552003JSP552003 Posts: 222
    I've just recently purchased a Fender Hot Rod Deluxe and I don't know a whole lot about tube amps so this may seem like a stupid question. So if the tubes are glowing a little red then it is time to replace them?
  • mccreadyisgodmccreadyisgod Bumfuq, MT Posts: 6,395
    Glowing faintly is okay. Glowing bright is a sign of the apocalypse.

    Usually, if a tube is going, it will glow quite a bit brighter than the rest. The plates will get bright reddish-orange. Shut the amp off immediately if this ever happens, and get it to a doctor before firing it up again. That is bad, bad news.

    Read the Trentino article for more info, tips, etc.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    The slight yellowy orange glow in the bottom is good. In fact its hypnotic and wonderful. Bad is when the plates on the inside glow RED. You'll notice a definite difference in sound too. The trentino article has good references on when to change tubes. Most people don't play all that much. There are some old amps from the 60's that have never had a tube change but usually filter caps and sockets wear out over about a 10-15 year period and need to be changed for optimum tone. It's all in the Trentino (builder of Mike and Stones amps last tour) article. If your amp has a standby let it warm up at least 30 sec on standby.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • mccreadyisgodmccreadyisgod Bumfuq, MT Posts: 6,395
    Here's a good four-part article from the Marshall folks:
    http://www.marshallamps.com/images/extra/lifeofvalves/lifeofvalves.html

    Always best to leave things to the pros when you're unsure. The capacitors in tube amps can kill you quite easily.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    Originally posted by mccreadyisgod
    Here's a good four-part article from the Marshall folks:
    http://www.marshallamps.com/images/extra/lifeofvalves/lifeofvalves.html

    Always best to leave things to the pros when you're unsure. The capacitors in tube amps can kill you quite easily.

    good article. KT66's are nice.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • mccreadyisgodmccreadyisgod Bumfuq, MT Posts: 6,395
    Originally posted by Pacomc79
    good article. KT66's are nice.

    Yes they are...

    But so are 5881's.

    But I still prefer 6V6's.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    Originally posted by mccreadyisgod
    Yes they are...

    But so are 5881's.

    But I still prefer 6V6's.

    I do also love the 6v6 and big brother 6L6. I'm seriously thinking about a 6L6 amp but I want a new guitar and effects and stuff first. so maybe in a year or 2.

    I prefer EL-34's to 5881's just too much power for me.

    The Dr. Z Z-28 should be right up your alley. 6v6 power and 4 10"s. It should just say. the MIG model.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • mccreadyisgodmccreadyisgod Bumfuq, MT Posts: 6,395
    Originally posted by Pacomc79
    The Dr. Z Z-28 should be right up your alley. 6v6 power and 4 10"s. It should just say. the MIG model.

    Depends on the speakers.

    EL-34's break up about as nice as any power tube out there... But nothing sparkles like a 6V6.
    ...and if you don't like it, you can suck on an egg.
  • Pacomc79Pacomc79 Posts: 9,404
    Originally posted by mccreadyisgod


    EL-34's break up about as nice as any power tube out there... But nothing sparkles like a 6V6.

    no Kidding listen to a bogner with EL-34's


    6L6 maybe? A few Twin owners would beg to differ.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • 62strat62strat Posts: 638
    ok well a 3 hour rehearsal last night and not one problem...hmmm, lose connection somewhere? fell back into place? still bring it in? probably....damn
  • Pacomc79Pacomc79 Posts: 9,404
    Are you plugging in to different outlets at times? Occasionally there are voltage problems that effect these kind of things and that could cause it. I'm thinking since obviously you gig with it that even though you probably are not throwing it around the general movement is affecting the internal parts. Wear and tear so to speak. It's probably a loose soldier joint brought on by stress on them due to volume and movement.
    My Girlfriend said to me..."How many guitars do you need?" and I replied...."How many pairs of shoes do you need?" She got really quiet.
  • who's_pearljam?who's_pearljam? Posts: 2,104



    How can you tell when a tube is going out?

    It has a glow about it! Ha Ha HA HA !:D

    It's a joke son!
    Be kind, man
    Don't be mankind. ~Captain Beefheart
    __________________________________
  • who's_pearljam?who's_pearljam? Posts: 2,104
    Sounds like a loose tube socket or maybe internal wire.
    Spraying the sockets with electrical cleaner and resetting the pins on the tubes might do it. Those things can be very random.
    If that doesn't do it,,,,amp tech!

    Good luck!
    Be kind, man
    Don't be mankind. ~Captain Beefheart
    __________________________________
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