1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Airline bias-vary tremolo isn't working

Discussion in 'Shock Brother's DIY Amps' started by DrewB, Aug 21, 2010.

  1. DrewB

    DrewB Tele-Afflicted

    Posts:
    1,625
    Joined:
    Feb 3, 2005
    Location:
    Independence, MO
    I have a mid-'60s Airline GVC-9045A that uses the bias-vary tremolo circuit (separate 12AX7). I have the amp up and running, but the tremolo doesn't work. There is a single speed control (no intensity). What is the likely culprit and what's the best way to diagnose it? There is a schematic link here: http://www.tdpri.com/forum/amp-central-station/225574-airline-identification.html

    Thanks for your wisdom!
     
  2. robt57

    robt57 Telefied Ad Free Member

    Posts:
    23,815
    Joined:
    Feb 29, 2004
    Location:
    Portland, OR
    Confirm that tube is good ? Swap the 12ax7s maybe...
     
  3. DrewB

    DrewB Tele-Afflicted

    Posts:
    1,625
    Joined:
    Feb 3, 2005
    Location:
    Independence, MO
    Yep, did that w/o any luck.
     
  4. TNO

    TNO Friend of Leo's

    Posts:
    3,511
    Joined:
    Apr 25, 2003
    Location:
    NC-USA
    It's probably the caps. There should be three caps right together on the board. Possibly will all be the same value. Replace them with any decent cap of similar value and voltage rating.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.