Fender Hot Rod Deluxe FX Loop problem

Discussion in 'Amps and Cabs' started by coltranemi2012, Feb 24, 2012.

  1. coltranemi2012

    coltranemi2012 Supporting Member

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    Hi when I plug in a cable into the "Power Amp In" of the fx loop it seems to get very very quiet and distorted...almost like cutting or something...anyone have any ideas? Thanks!
     
  2. cap47

    cap47 Member

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    Could need cleaning! Spray some D5 Deoxit in both jacks and work a plug in and out.
     
  3. Crimson Queen

    Crimson Queen Member

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    Do you use the loop normally with an effect? It is buffered with an op-amp. The circuit is bypassed until the loop is used. I have seen some fail in these amps. It's an easy fix though. If you use the loop without any problems but only get the distorted sound by plugging into the power amp in, then it's probably something else. What are you using as a preamp when plugging into the power amp in?
     
  4. coltranemi2012

    coltranemi2012 Supporting Member

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    well I just plug a cable into both the "preamp out" and the "power amp in"...so basically the send and return of most loops...and it only happens on the in...I plug delay and reverb into it. Anything i can do? Thanks!
     
  5. coltranemi2012

    coltranemi2012 Supporting Member

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  6. Nickstrtcstr

    Nickstrtcstr Lactose Intolerant Guitar Slinger

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    If you have a PA or another guitar amp with a loop you can take the preamp out through your pedal into a PA channel or another amps power amp input. This way you can rule out the preamp's output if there are no issues. If there are issues it most likely is a cold solder joint on the power amp input jack. These amps are infamous for cold joints. Great sounding amp but they have a few manufacturing issues that rear their heads periodically.
     
  7. coltranemi2012

    coltranemi2012 Supporting Member

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    Nickstrtcstr...I'm confused..how would I do that? Thanks!
     
  8. Crimson Queen

    Crimson Queen Member

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    Put a cable between the preamp out of your amp and plug it into the power amp in or effects return of another amp.

    When you put a pedal in the loop, does the amp work correctly?
     
  9. coltranemi2012

    coltranemi2012 Supporting Member

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    no...that's what I mean...when I plug a pedal into the FX loop it doesnt work...when I plug a cable into the "out" it's ok so far..but when I put the other cable into "in"..it sounds like it barely works...almost like when you turn an amp off but keep playing and its distorted and it is quiet...it sounds like that..Thanks a lot guys!!
     
  10. Crimson Queen

    Crimson Queen Member

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    Troubleshooting is hard to do remotely.

    Are you plugging the preamp out of the amp into the input of the pedal, and the output of the pedal into the power amp in the amp?
    Have you tried other cables?
    Is the pedal powered with a power supply and functional otherwise (like in front of the amp with the same cables)?
    Have you brought the amp to a store who could troubleshoot this for you?

    Like I said earlier, the effect loop is buffered with an op-amp. They have been known to fail; it happened in my amp, and the sound was quiet and distorted. The loop is completely bypassed when not used, so the problem only surfaces when something is plugged into it.
     
  11. coltranemi2012

    coltranemi2012 Supporting Member

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    yes..I tried other cables and other amps...everything works fine with my Badger 30...did you just give to someone to fix and how much was it roughly...sounds like we have a similar problem..and Thanks!
     
  12. Crimson Queen

    Crimson Queen Member

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    I went to the dealer. They diagnosed the faulty op-amp and changed it. It was not expensive. Today, I could change it myself, but I would not be able to tell that it is defective.
     
  13. coltranemi2012

    coltranemi2012 Supporting Member

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  14. coltranemi2012

    coltranemi2012 Supporting Member

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    ok...i think it may be the input...can I change the amp in input? Is this hard to do? do I need to sotter anything? also...how do I know which part to buy? Thanks!
     
  15. Crimson Queen

    Crimson Queen Member

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    You need to take the amp to a store with a repair service.
     
  16. coltranemi2012

    coltranemi2012 Supporting Member

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    yea it's just they wanna charge like $100 or more...I was hoping to avoid that
     
  17. tuubes

    tuubes Member

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    Hey man, did ya get anywhere with it?

    jim
     

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