HELP!! I think my amp (WT 800) is blowing up?!!!

Discussion in 'Amps and Cabs [BG]' started by DieselKTM, Sep 30, 2017.

  1. SOS folks.... I use a WT 800 and have been gigging regularly with it for several years.

    Its had its quirks but lately I have been experiencing the entire PA... Shutting down Losing power and moments later powering back up. At first I thought is was the venue's power circuit, Then it happened at another. Then another.... with this one being the House PA (Same power circuit as my amp.) That told me its not PA related. It seems to occur happens when I push my amp. ( Pedal, boost during hard rocking runs). I'm running the amp bridged into a 4ohm 410 XST.

    Everything on that circuit shuts down.... Lights, PA, Monitors, like the circuit breaker tripped and then it comes back on after a few seconds.

    My gut is telling me my amp is pulling the circuit down. Ive been playing these very same venues for years, Same gear, no change.

    Have any of you experienced this. Is my amp about to grenade? :nailbiting:

    no burning smell or anything.
  2. coreyfyfe

    coreyfyfe Supporting Member

    Nov 19, 2007
    boston, ma
    Per your amp's user manual:

    Bridged Mono Out- Use this jack only for Mono bridging. Do not use any other output in conjunction with this. Note (The Minimum load in Bridged Mono is 8 Ohms). Use caution this is a high voltage and high power connection point.
    agedhorse and BadExample like this.
  3. BassmanPaul

    BassmanPaul Inactive

    User error - Sorry!
    agedhorse and BadExample like this.
  4. BadExample


    Jan 21, 2016
    This would be a good time to re-RTFM in its entirety. Make sure you understand it and ask if you don't.
    agedhorse likes this.
  5. bobcruz


    Mar 10, 2004
    Some of the late model WT800s do bridge into 4 ohms but Marshall has gone back to recommending only bridging into 8 ohm loads.

    OP, it does sound like power draw is exceeding the circuit's capacity. You can borrow or buy watt meters that tell you how much current a device is drawing (I borrowed one from our town's power company to test an old fridge). You may have to find different circuits for some of the gear.
    Munjibunga and BadExample like this.
  6. Munjibunga

    Munjibunga Retired Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    It depends. The early models would bridge only into an 8-ohm load, but the B and C models will bridge into 4 ohms for 1,100 watts.
    johnpbass likes this.
  7. Thanks Guys....

    As it turns out I'm supposedly OK with 4ohms bridged. Further thought revealed that a new 6 way power strip is the culprit. Started using it a sort time ago. It was in the main power string to both my rig and the PA. My trusty Eden appears to be fine.

    "Step 1. Ensure that your amplifier is switched off, preferably at the electrical outlet. Step 2. Ensure that Bi-Amp mode is switched off (switch in the IN position) never turn the Bi-Amp mode on during Bridge Mono Operation as it will overload the amplifier. Step 3. Ensure that Bridge Mono mode is switched on (switch in the OUT position). Step 4. Ensure that your amplifier is connected to cabinet with the correct load and power handling (880W at 8Ω and 1100W at 4 Ω) using the Bridge Mono output socket on the rear of the unit."

    Lesson Learned;

    Beware of cheap power strip surge protectors!
    bobcruz likes this.
  8. bobcruz


    Mar 10, 2004
    How did you determine it was the power strip--replaced it and the problem went away? Does it have a brand name that you can post here as a warning? Bob
  9. Home Depot Cheapo. Gigged the last two nights... without a hitch. So... I have a power conditioner mounted in my rig rack. I most often plug the PA mixer into my rack conditioner... so having that cheapo surge protector in the front of the chain was not really needed anyway. My advise is beware of generic "surge protection" devices on dynamic loads like live sound systems. I'm going to make my own power "strip". Should have done that a long time ago.

  10. Ampslut

    Ampslut Supporting Member

    May 15, 2017
    Glad you found the problem
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