More amp trouble - second SOS!

Discussion in 'Amps & Cabs' started by RVA, Nov 14, 2015.

  1. RVA

    RVA Well-Known Member

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    It was a power tube and a power fuse. Yes, I have searched far and wide for an answer. I am not ready to concede defeat yet!!!

    Also, the fact that you found my Peavey forum post likely means that you were searching for an answer for me. That is very kind. Thanks again!
     
    Last edited: Nov 26, 2015
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  2. ivan H

    ivan H Well-Known Member

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    Hi, I would really think about taking it to ur tech. Chasing down the source of hum can be frustrating even for the experienced. The $95/hour is getting u his knowledge, experience & proper test equipment, plus should also get u some warranty on the repair, not to mention he should have u back up & running properly in short order. But back to ur problem, catastrophic power tube failure & popped the main fuse. Firstly u need to know wot caused the tube to fail (& wot failed). It may have been caused by a tube fault, but may just as well have been caused by some other fault. Simply re tubing is treating the symptom of an as yet undiagnosed cause. Also, when power tubes fail like this they can often do damage to the tube socket, & more importantly, components supporting that tube. All need a thorough check. The fact that the main fuse blew & not the HT fuse is a good indication of where to focus on looking for faults. I don't mean to discourage u, I'm all for learning to service ones own valve amp, its just that u r jumping in where its rather deepish. A quick question, has the tech u mentioned worked in the area for long? If he wasn't competent he wouldn't last in the business. Hope this helps. Cheers
     
  3. Dave_Death

    Dave_Death Well-Known Member

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    I would definitely get the input transformer checked out.
     
  4. RVA

    RVA Well-Known Member

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    Ok, so maybe I should concede!! The shop has been around a long time and does many vintage restorations. They are very well known. They did say that for $ 75 check out fee they would give me a diagnosis. Thanks guys
     
  5. eS.G.

    eS.G. Well-Known Member

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    So for 150.00 you could get a Micro Terror by Orange and use the Peavey as a Cabinet------ Trying to find a silver lining. ;)
     
  6. eS.G.

    eS.G. Well-Known Member

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    So for 150.00 you could get a Micro Terror by Orange and use the Peavey as a Cabinet------ Trying to find a silver lining. ;)
     
  7. eS.G.

    eS.G. Well-Known Member

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    well thats weird.,
     
  8. RVA

    RVA Well-Known Member

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    Well, the silver lining is that the Peavey Triumph issues allowed me to rationalize the Peavey Classic 50 purchase! I will get the Triumph working again though. I am foolishly attached to it - and sentimentality can get expensive!
     
  9. eS.G.

    eS.G. Well-Known Member

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    Oh I had a Peavey Valve King 8

    [​IMG]

    Not really sure why I didn't bond with it more-------- I never REALLY gave it it a fighting chance.......hhhhmmmmmmm
     
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  10. RVA

    RVA Well-Known Member

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    Never tried one but looks cool. Peaveys are for players!
     
  11. eS.G.

    eS.G. Well-Known Member

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    Great amp ----Class A Tube amp and can be scored for 150 or less.
     
  12. ivan H

    ivan H Well-Known Member

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    I would not necessarily think "new amp" too quickly. There may well be very little wrong with ur triumph (but a new amp is always good). If u do take it to the tech, be sure to also take the power tube that failed. This will be the first thing he'll check over in diagnosing wot went wrong. The first thing that comes to my mind is a "heater to cathode short" in that power tube. This would cause failure of the tube (internal arcing) & blow the main fuse, not the HT fuse. Also, if the heater circuit has "balance resistors (usually a 100 ohm resistor from each side of the heater supply to ground), as many amps do, they would most probably have been damaged by the incident. As their job is to prevent hum by balancing either side of the PT's heater winding, even just one of them falling out of spec will result in 60 cycle hum. It may well not be ur problem but its where I'd look first. Cheers
     
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  13. RVA

    RVA Well-Known Member

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    Great analysis! Do you charge les tha $ 95 an hour?!

    I could not save the failed tube for examination (not that I had thought to do so) - it was severely cracked and was taken out in pieces. I will be sure to tell them that however.

    Oh, and the Classic 50 stays! Thanks again guys!
     
  14. chilipeppermaniac

    chilipeppermaniac Well-Known Member

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    I had some issues with my 1972 Marshall JMP a few years ago and wound up taking it to a tech.
    The issues I had were fuse blowing issues and then eventually my amp wouldn't power up even with a new fuse. The tech told me his tests showed a bad Power transformer. I bought a Marstran clone of my original and had him install it. I figured the amp would be good to go after that. I love the amp but really only play it occasionally. Anyway, on one occasion I was playing it at home when it started to sound funny between channel 1 and 2 like 1 side was quieter by a wide margin than the other or I was hearing unusual background noises, I don't precisely remember. Anyway, then it started blowing the fuse again. Back to the same tech a year or so later by this time. This time he said the caps needed replacing. I did not have an issue with this because as a general rule caps have a 10-15 year life span. The originals were approaching 40 years old by this time. I guess my point is while I could have hunted on the web for answers and tried to guess my way thru repairing it myself, I took it to a tech who I was told had all necessary test equipment I don't have nor have become proficient with. He has a good reputation for amp work on other local pro's gear and he got it working again in a reasonable time frame. This makes his fees worth the similar $95/hr price in terms of opportunity cost for me to go make money at my specialty and let the tech save me from the cost of acquiring numerous expensive electronic test tools and wasting time essentially guessing why my amp was acting up and throwing parts at it.

    Despite advising as I have, eventually one day I plan to buy equipment and educate myself about electronics to where I can not only fix my own stuff, but also get the satisfaction in learning a valuable set of talents to carry me through in my arsenal of life's acquired skills.

    RVA, Ivan has good advice for you as well. I wish you luck in getting your amp fixed.
     
    Last edited: Dec 26, 2015
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  15. 67plexi

    67plexi Well-Known Member

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    This may help http://www.schematicsunlimited.com/p/peavey/peavey-triumph Voltage chart out the amp.
    As ken Fischer told me start with B+1 508 Volts AC secondary side of the power transformer and work your way from that point
    If you don't understand this send it out to a qualified service center.
     
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  16. RVA

    RVA Well-Known Member

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    Thank you. I am trying to understand it. Does that count?
     
  17. chilipeppermaniac

    chilipeppermaniac Well-Known Member

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    Last edited: Jan 20, 2016
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  18. chilipeppermaniac

    chilipeppermaniac Well-Known Member

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  19. chilipeppermaniac

    chilipeppermaniac Well-Known Member

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  20. chilipeppermaniac

    chilipeppermaniac Well-Known Member

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    Last edited: Jan 20, 2016
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