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Ampeg svt4 cuts out....Overheating?

Discussion in 'Amps and Cabs [BG]' started by jessejms03, Sep 1, 2008.

  1. jessejms03


    Sep 1, 2008
    Just got an Ampeg SVT-4 and I have it mono bridged into a 410HLF. I put the amp in a rackmount case with conditioner, tuner. So at first band practice it would cut out periodically. There would be no sound whatsoever for a minute or so. Checked cables batteries etc. I know that there are vents on the back and sides, but it got really hot to the touch. Could it be overheating? Its made for a rack so....?? Any help would be greatly appreciated!
  2. Ampeg SVT

    Ampeg SVT Son, I am disappoint.

    Are you crazy? Running 1200 watts into a cab that can only handle 500?
  3. jessejms03


    Sep 1, 2008
    Im not using all watts for sure....sounds great though....until it cuts out
  4. Gearhead17

    Gearhead17 Supporting Member

    May 4, 2006
    Roselle, IL
    Let's not start the overpower underpower thing again.....the 410hlf can handle 1000 watt peaks with 500 watts continuous. The SVT 4 PRO bridged into the 410hlf will work just fine as long as you don't go crazy with the low end boosting and volume levels

    Try taking the 4 PRO out of the rack and see if the amp stops getting so hot - it may just be fixed right away. It may be overheating, even though it's a rackmount design, it has side vents which are quickly blocked by most racks out there. Some people have had problems with this, while others have been running it rackmounted and never did have a problem. Some installed vents on the rack unit, and some added a portable fan in the back.
  5. jessejms03


    Sep 1, 2008
    Thats a great answer thanks. The top gets so hot its hard too keep my hand there. Pretty hot. So if it was overheating, the result would be the drop out...then resumes by itself in about a minute...? I would love to hear how fans or side vents have worked out for people.
  6. anyonefortennis

    anyonefortennis Supporting Member

    Jun 28, 2005
    Lincoln, NE

    Not what he came here for.

    Not a problem either...
  7. xshawnxearthx


    Aug 23, 2004
    new jersey
    first try taking it out of the case. if that works drill some holes in the side of your case where the fan would be.
  8. Gearhead17

    Gearhead17 Supporting Member

    May 4, 2006
    Roselle, IL
    It's the thermal shut down protection circuit - the amps stops working to stop generating heat from itself, once it comes back on, th unit reached a decent operating temperature.
  9. RickenBoogie


    Jul 22, 2007
    Dallas, TX
    Yeah, it's actually a good thing that it cuts off, otherwise it might check out.
  10. jessejms03


    Sep 1, 2008
    Anyone have luck with holes and a fan?
  11. Your amp has a problem, it's not normal that it gets hot like that, unless you are cranking it ridiculously and that the warning ligths on it are flashing like a christmas tree.

    I had an Svt-4 for 2 or 3 years and it never got really hot. It was racked all the time, used for 4 hour long rehearsals and gigs, I never ever had a trouble with it.

    Don't listen to the people telling you to drill holes in your rack or to add a fan, it simply is not normal of your head to overheat like that.
  12. jessejms03


    Sep 1, 2008
    Great advice all around thanks. Im going to swap it out and see what happens. Drilling and fans dosnt seem right.
  13. xshawnxearthx


    Aug 23, 2004
    new jersey
    mine doesn't overheat because i have it in a shock mount case. if i purchased an skb, the first thing i would do is drill holes on the side of the skb case to allow better ventilation.
  14. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Racks are notorious for overheating 4PRO units...... Some have less than an inch of clearance, which pretty much shuts off airflow, which the 4PRO has to have to stay cool.

    The 1 minute drop-out is pretty typical of a heatsink overheat situation. if it were the transformer overheating, it would be off for more like 20 minutes.

    The question is why it overheats...... The rack is a very likely cause, so take it out and see if it is fine then.

    if so, vent the rack.

    If not, there is an issue with the amp, probably it is biased a little hotter than it should be.

    But I don't think you will have a problem once it gets decent airflow.
  15. kenneth206


    May 28, 2009
    Brothell, WA
    I had a similar problem but my SVT4 wasn't running hot nor was it in a rack. I had a shop in Portland take a look at it and they re-soldiered some contacts on the preamp and said it was a common problem they had seen with these amps and the cheap contacts being rumbled apart :bassist: That was 4 years ago and I haven't had a problem since.

    Sorry to bump an old thread but I came across this looking for a rack case and I thought this might be useful info to someone else.

  16. I had an SWR SM500 that would overheat all of the time. I attached a portable fan to the back my rack and it never over heated again. But I think that there's a problem with your head. I had a 4PRO a few years back and never had an overheating problem
  17. Krause


    Mar 17, 2009
    Winnipeg, MB.
    I've had my SVT-4PRO since 2000, has been in a rack case since the day I bought it and not once in 9 years has it cut out on me. Never even gets hot. I would have some one take a look at it. Maybe I just got lucky.
  18. Hammr


    Jul 11, 2008
    I'm running the same setup, SVT-4PRO into 410HLF (Not bridged mono tho). I have it in in this rack:


    I left 1 rack space on top and bottom (with mesh vent panels to make it look nice :D) to get some air flow around the head.

    No problems at all,but i might mount a little rack fan to rear rails to be on the safe side
  19. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Some folks I know say that SKB stands for "Shoulda Known Better"....... I'm not so mean as that, but the SKB are notorious for being tight on the sides........ the 4PRO needs more side room than the SKB racks I have seen will give.

    An extra fan or holes............ both good.
  20. smallexpDSC_2816.

    Drilled 2 pcs. of 3" on each side of the SKB Roller case, giged it last night: no problems.
    The complete set got warm (not hot) but that's because a SVT4pro paired with a SVP-pro have about 8pcs of 12AU7/AX-7tubes.
    Add up the solid state 1200Watts power amp and the heater is on!!



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