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Faulty tube? fender hot rod deville

Discussion in 'Amps and Cabs [BG]' started by jeffgnr90, Mar 18, 2014.

  1. jeffgnr90


    Aug 4, 2011
    Hi folks. I know this isn't bass related but I'm trying to help out a friend. He just acquired a fender deville today. He played it for 20 minutes, took a break, came back to it and the amp started making popping sounds with a little bit of crackling. I'm thinking that maybe its a bad solder joint or capacitor. Now if he turns the amp off and then back on, its fine until about 5 minutes in where it starts to pop again. The thing was returned recently retubed so perhaps this is a result of a poor job or a faulty tube? Needless to say its a bit of a bummer. Any insights?
  2. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    There are many possibilities that a tech could check out but the first thing to try is swapping out the tubes one at a time.

    It makes sense to try the 12AX7's first since they don't cost a lot. Get a known good one and see what happens. Next I'd check that all the connectors are seated properly inside the chassis.
  3. Mine has a blown output transformer.
    No sound, and it makes the power tubes get REAL BRIGHT RED until I shut it off.

    IMO, these are boat anchors.
    Mine is a 2x12, obscenely loud, very heavy, and probably expensive to fix.
    I got this one for my daughter years ago when she started up... she now plays a Marshall JCM-800...
  4. Probably a bad tube but I would not rule out a broken trace or bad socket. Those come with about the cheapest printed circuit boards I have ever seen.
  5. Passinwind

    Passinwind I Know Nothing Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    The screen grid resistors like to unsolder themselves from the circuit board, but sometimes they just burn up instead, and/or char the board.

    Bruce: these are not all that hard to repair (for a tech familiar with circuit board era Fenders anyway) and there are many well known mods out there to help reliability and tone. If you daughter likes the JCM800 she will likely hate the DeVille anyway though.
  6. If this is a newer model and not the older vintage build reflow the solder on all the tube sockets. If the nuts get loose on the input jacks the solder joints and the jacks themselves fail pretty quick. I have a customer on his second set of jacks in four years. V2 is very sensitive to mechanical noise inside the tube.