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SVT 3 smoke and sparks and fire

Discussion in 'Amps and Cabs [BG]' started by xrockstrongox, Jun 1, 2014.


  1. So I was playing and the string hit the pickup. It made a nice little input spike and the next thing I know sparks and smoke are shooting out of my svt 3. Any ideas on if it can be fixed?
     

    Attached Files:

  2. Take it to a qualified repair shop if it is worth the money to you. Whenever fire is involved it signals a very major and likely dangerous problem.
     
  3. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Dang dude, that got quite toasty!
     
    Geri O likes this.
  4. Hi.

    +1 For tech time.

    An estimate shouldn't be more than 1 hour bench fee.

    Anything's possible, but if strings hitting pickups would cause an amp to self destruct, I suppose there wouldn't be many amps left ;).

    Just like older SWR's, SS Ampegs have a tendency to have bias problems, especially if the discretes have been replaced with non matched ones/banks.

    Regards
    Sam
     
  5. Would a bias problem cause it to go fuzzy sounding kind of in and out? cause if so then yes, that was what was going on.
     
  6. Hi.

    I'm mostly a tube-head, but IMLE in Fet amps any bias problem usually cooks the Fets in a split second so no time to hear the warning signs, but on most conventional transistor designs and some Fet designs AFAIK the first symptom of a drifted bias is the nasty non-musical distortion the incorrectly biased output section produces.
    An incorrectly biased SS power amp also heats up very quickly.
    Of course, if the bias is completely lost, (almost) no output device can take that without immediate self destruct.

    The symptoms mentioned above IME do not go in and out, but different amplifier topologies and different ways of biasing do produce different symptoms.

    There's quite a few SS Ampeg techs here at TB, and they can most likely tell what's in that cooked section of
    Your SVT3's PCB, and they can also most likely tell whether there's other problems as well.

    Unfortunately, it's a very strong possibility that the Fets at least are gone.

    Regards
    Sam
     
  7. *blink blink* So.....bad?
     
  8. Razman

    Razman

    Feb 10, 2005
    Orange Park, FL
    Our SVT6-Pro fried last July, not sure what caused it but it was definitely well done. Would have been replaced but we sent it off for repair and paid almost as much to fix it as a used replacement would cost. It now produces some noise occasionally, IMO it should have been replaced.

    I'm thinking you should ebay yours for parts and move on to the next one as from a cost perspective you will exceed the point of diminished returns. Sure, anything can be fixed, but for how much and will it be back to 100%?

    If it were me, I'd be looking for a local deal on CL or in a pawn shop.

    Raz
     
  9. Hi.

    IMO, bad.

    Every time a PCB scorches like that before the fuse(s) kick in, there's a strong possibility that some PCB traces have at least lifted if not melted, and that means that very high current has passed through a lot of components.

    If You like the amp, I'd look at finding a tested power amp module on evilbay, or I would search for a suitable class D module(s) to replace the power amp section completely.
    IIRC, a lot of that amps charater is in the power amp topology though, so switching to class D may not sound the same.

    Regards
    Sam
     
    SanDiegoHarry likes this.
  10. What would I be looking for in an svt power module?
     
  11. SanDiegoHarry

    SanDiegoHarry Banned Supporting Member

    Aug 11, 2008
    San Diego, CA
    Magic Smoke???
     
  12. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Forget it. The 3 Pro's power amp has a driver section which contributes a good amount of character to the amp, and you won't get that in other amps.
     
  13. So, Jimmy, lost cause?
     
  14. will33

    will33

    May 22, 2006
    austin,tx
    Pethaps not completely lost, but likely cost as much to get repaired as it would to just buy another used one in good shape.

    So yeah....kinda lost.
     
  15. MoeTown1986

    MoeTown1986 Supporting Member

    Sep 14, 2010
    SoMD (Mechanicsville)
    It saddens me to see this! If my SVT-3 Pro fried, I'd seriously cry. I love mine soooooo much! Good luck getting it fixed. And, if not, they pop up on CL all the time for CHEAP since everyone is on a lightweight kick these days...
     
  16. jeffmaxwell

    jeffmaxwell Commercial User

    Oct 8, 2007
    San Diego, CA
    owner, Silver Hammer Designs
    Not a lost cause. Find a tech familiar with that amp and get it evaluated. Good chance that the pcb is not destroyed--sparks and smoke probably resistors burning up not necessarily damaging board. Smoke is easily cleaned off board. I have repaired many of these amps after the magic smoke escaped. Don't give up until you get a tech to check it out.
     
  17. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    More or less my take on it. That said, it doesn't always have to be that way. Could be a few small parts. Then again, it might have taken out a lot of stuff. You don't know till a tech gets in there. It'll cost you a bench charge to get them to look at it, though they will apply it to the cost of the repair usually. A bit of a gamble at this point, I'd say, with pretty much even odds either way.
     
  18. MoeTown1986

    MoeTown1986 Supporting Member

    Sep 14, 2010
    SoMD (Mechanicsville)
    At least if he got it repaired and serviced (biased and such) it'd probably be in better shape than a used one that could have been abused and not really taken care of.
     
  19. Bass 45

    Bass 45

    Jun 23, 2011
    Tempe, Arizona
    I agree that you should take it to a tech before giving it away.

    I have had two amps smoke that turned out to be very minor repairs - an SVT-3 Pro with an issue at the IEC plug and a PB800 that just needed a new power switch. They both cost less then $20.00 to repair.

    Also, the bias being a bit off does not cause a catastrophic failure - but it will sound fuzzy/distorted.

    Adjusting the bias should also be a cheap fix if there is not a more serious problem.
     
  20. Bass 45

    Bass 45

    Jun 23, 2011
    Tempe, Arizona
    Also - you can unscrew the top and have a look inside.

    If it looks like a clump of lava in there - you might have a serious issue.
     

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