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Markbass Compressore: How to change the tube?

Discussion in 'Effects [BG]' started by DirkP, Jan 29, 2014.

  1. DirkP


    Jan 18, 2013
    Hamburg, Germany
    today I wanted to change the tube in my Markbass Compressore, 'cause it starts to crackle and distort the signal from time to time. I thought that I only have to loosen the 2 screws that hold the little sheet underneath one can see the tube. But although the screws were tight both could not be removed, I could loosen then endlessly without any effect. I used the right tool. Do I really have to open the entire device?
    Anyone here who ever replaced the tube in his compressore?
    Thanx in advance,
  2. Twocan

    Twocan Living the Dream Supporting Member

    Oct 5, 2009
    Medway, MA
    The top grate does not come off unless you access it from underneath. You need to take the sides off and detatch the top from the bottom of the unit. Before you buy a new tube, take it apart and double check all of your connections. My foot swtich was a little loose and as a result I had the problem you describe.
  3. DirkP


    Jan 18, 2013
    Hamburg, Germany
    Many thanks for your support, Twokan!
    Although I think it's really the tube, 'cause the noise and distortion sets in from time to time after minutes of playing without changing anything else.
  4. bongomania

    bongomania Gold Supporting Member Commercial User

    Oct 17, 2005
    PDX, OR
    owner, OVNIFX and OVNILabs
    That doesn't mean it's the tube. I would suspect the footswitch first. Maybe a dirty jack or pot.
  5. GretschBassist


    Nov 11, 2012
    It never hurts to have a spare tube lying around so whether or not you need it now, it wont be wasted money. I agree on checking the FS though as this is the weak spot of the unit. The only one I know of actually ;-)
  6. Twocan

    Twocan Living the Dream Supporting Member

    Oct 5, 2009
    Medway, MA
    DirkP - I had the exact same issue: Without warning I'd get 5-60 seconds of dirt/static/etc and then it would go away. In my case it was a loose footswitch.
  7. Resurrection batman....

    I have the same problem here? How did you fix the footswitch issue? Just by tightening the screw or was the connection to the circuit board non tight enough?
    Last edited: Apr 24, 2014
  8. Here's the footswitch and circuit board. Its soldered in place.

    EDIT: The link required a login. I just uploaded the image.

    Attached Files:

    Last edited: May 15, 2014
    totallyfrozen likes this.
  9. rtav

    rtav Millionaire Stuntman, Half-Jackalope

    Dec 12, 2008
    Chicago, IL
    I think there was a problem with your IMG tag - no pic appears in your post.
  10. "I think there was a problem with your IMG tag - no pic appears in your post."

    Corrected above.
    rtav likes this.
  11. javadog


    Mar 13, 2010
    I know this is an old thread, but has anybody replaced the footswitch and did it fix the noise problem?
    What is the best replacement switch option and where can I get one?
    What about the Carling or Dunlop switches?