Fender Twin Tremolo not working

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by coolharmony, Jan 20, 2008.


  1. coolharmony

    coolharmony Supporting Member

    Messages:
    115
    Joined:
    Jan 2, 2006
    Location:
    NYC Area
    The tremolo in my old blackface twin was working fine when I last palyed it; I turned on the amp last night after not using it for 6 months and the tremolo worked intermittently for a moment then stopped completely. Any trouble shooting tips for a someone with limited technical amp skills?
    thanks!
     
  2. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    In this order...

    Jiggle the RCA plug connections to the footswitch and make sure they're seated properly, including the reverb one - the ground for the tremolo switch is via the reverb jack.

    Take the bottom off the footswitch and check for bad solder joints. Squirt some contact cleaner/lubricant into both switches.

    Replace the tremolo tube (second from the power tubes) with a good high gain 12AX7. Tone and microphonics are irrelevant, so this is a good use for a tube which is no good on either of these grounds but otherwise works well.

    If none of that, it's probably the tremolo opto-coupler ('bug'/'roach') inside the amp, which seem to have a life expectancy in the 40-year range and are starting to fail increasingly often in older amps. Replacements are available from Fender, but it's a soldering job to fit it.
     
  3. coolharmony

    coolharmony Supporting Member

    Messages:
    115
    Joined:
    Jan 2, 2006
    Location:
    NYC Area
    John,

    Thanks so much, I'll try your suggestions; interestingly, the reverb works fine....
     
  4. John Phillips

    John Phillips Member

    Messages:
    13,080
    Joined:
    Mar 17, 2002
    Location:
    Scotland
    It will - the reverb needs the footswitch to turn it off, the tremolo needs the footswitch to turn it on. Most people don't even need the footswitch since that's how they use the amp - reverb, no trem.
     
  5. coolharmony

    coolharmony Supporting Member

    Messages:
    115
    Joined:
    Jan 2, 2006
    Location:
    NYC Area

Share This Page