Zwengel combo help please!

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by Noah, Feb 17, 2006.

  1. Noah

    Noah Supporting Member

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    Hello. I posted on this before once, but I think I may have found the root cause of a very troubling problem.

    I was gettting a horrible clangy distortion sound with my combo on the "modern" channel. I tried new tubes, took it to a tech twice, ect.

    Finally I discovered something when I messed with the effects loop. When I plugged a cable into the send and return and turned the knobs all the way up, the modern channel sounded good again. The only problem is the master volume really explodes when you try to turn it up now.

    When the cable is removed from the loop... clangy tone again...

    ANy ideas???
     
  2. Noah

    Noah Supporting Member

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    anybody got any ideas?
     
  3. Dave C

    Dave C Gold Supporting Member

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    Contacts dirty on shorting type jacks in fx loop ? Try cleaning them if you can , I've seen a similar problem on other amps too. Try turning send/return levels down to unity or nominal levels and see if that helps with mv problem.
    Dave C
     
  4. Noah

    Noah Supporting Member

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    I have to turn the effects loop knobs all the way up and keep a cord plugged in running between them to get the modern channel sounding correct. when I turn the send/return knobs down the clangy tone comes back and the gain dissapears. I have to keep both of them all the way up.
     
  5. Dave C

    Dave C Gold Supporting Member

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    Sounds like something is wrong in your fx loop , it shouldn't have to be all the way up to sound "right". Some fx loops have significant gain to drive fx levels of different units and the amp may sound better using this boost but I wouldn't think that would be normal to have to have the loop dimed to sound good. I'd suggest giving your tech or somebody else another shot at it.
    Dave C
     
  6. Noah

    Noah Supporting Member

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    Thanks for the help. I'm not sure what to do now. I guess i'll try to find a different amp tech here in town.
     
  7. ericb

    ericb Silver Supporting Member

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    I would have to agree with this assessment, based on seeing this with a few situations too..I've had it happen with fx loop jacks, but also input jacks etc. Your problem sounds like a dirty (or shot) fx loop jack though. I have an Allen and Heath GLseries old mixer that has the same thing happen on the fx inserts on their channels. Once you jump them with a cable the problem goes away. GOOD LUCK and it sounds like a simple fix for someone... Of course it could be something different if this is a tube driven fx loop and a shot 12ax7 or tube socket,etc also but it fits the characteristics of what he says above

    ERIC
     

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