solid state question, Fender Pro 185 problem

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by awaywardson, Aug 26, 2008.

  1. awaywardson

    awaywardson Member

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    are the insides of solid state amps as dangerous as the insides of tube amps? I have a Fender Pro 185 that keeps having the same problem, and it's 100 bucks to the tech each time and i thought maybe i could fix it.
     
  2. EdMan57

    EdMan57 Member

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    That's a good question.I don't believe that solid state amps use or need the large filter caps found in tube amps,which I believe store most [if not all] of the dangerous built up electrical charges.Of course,I could be quite wrong,as well.Good luck.

    Ed
     
  3. donnyjaguar

    donnyjaguar Member

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    What's the problem its having? It sounds to me that the tech is replacing the failed components but not fixing the problem. This is typical with journeyman electronics techs. Its not a problem with engineering techs, like myself. :)
     
  4. awaywardson

    awaywardson Member

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    umm, i'm paraphrasing, but he told me that where the jacks connect to the board it keeps coming undone (?) and that the back/bottom of something is very heavy and that's why. thought maybe i could figure it out and then somehow brace up whatever is pulling this loose. he told me that as long as the amp was not moved very much it wouldn't happen, but likely from riding in my band trailer was the cause of the repetitive damage. this amp has been in storage for a few years. i bought it used, played it for a while, paid 100 bucks two different times to have the same thing fixed, then the third time i just got a new amp and stuck this one in the closet. i pulled it out the other day and figured i'd either pay to have it fixed and put it on the 'bay or craigslist or here (or all 3) or use it for practice or whatever...
     
  5. jdh

    jdh Supporting Member

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    Awaywardson,
    The US Department of Energy sets the safe threshold at 50V and 10 joules. This is the standard that all of our national labs follow. A 100 watt rms solid state amp driving an 8 ohm speaker will have a minimum of +/- 40V rails, so this is beyond what you can touch without the possibility of lethal consequences: 80V from + to - rail (note: joules= 1/2 C*V*V). A trained technician will not have a problem working around this amount of energy. If you have any doubts then pay a professional and live to rock and roll another day. That said, this recurring problem is possibly a design flaw in addition to having other things wrong than just the parts your tech changed twice. As donnyjaguar suggests, you need some engineering talent to fix this thing.

    Dennis
     
  6. donnyjaguar

    donnyjaguar Member

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    I've seen this sort of thing before, generally on high-production type practice amplifiers. What you need to do is replace the socket with a more typical style that uses flying leads, thus divorcing it from the circuit board. Some cutting of the PCB may be necessary to fit it in, but it will fix the problem. Its not a design flaw as such, but more the result of a cost-reduction strategy in manufacture. I work on high-end hi-fi gear a lot and often you see beautifully made pieces with a glaring shortcoming like this.
     
  7. awaywardson

    awaywardson Member

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    super. thanks guys.
    so this is why people love AND hate Fender...
     
  8. cram

    cram Member

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    I have this exact same amp. I use it as backup and in alternate places I go - leave it at friend's house I'll return to jam with the following week or bring this instead of my nicer amp to an outside jam.

    problems - I believe there's a problem with the reverb unit or the connection there. It is not consistent, but if I have the reverb turned up, I run into problems with the amp cutting out. If I turn the reverb all the way down it works.

    This is not meant to hijack the thread, but I think it points to how tempermental these amps are.
    Great low end amp though. I like the overdive sound on it for a ss amp.
     
  9. A440

    A440 Silver Supporting Member

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    unfortunately, they may be repairing the symptom and not the cause

    I used to own one of these amps, it had a nice fender clean tone which worked great for funk, etc. I just used the clean channel with pedals and the efx loop was pretty good on this too.
     

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