2 to 3 prong power on Sunn 200S

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by aortizjr, Nov 29, 2005.

  1. aortizjr

    aortizjr Member

    Messages:
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    Joined:
    Nov 24, 2004
    Location:
    Santa Fe, NM
    I posted earlier about tracking down some hum with this amp. I also thought that the conversion to a 3 prong ground would be trivial.

    However, the Sunn 200S has a phase reverse switch and I remebered learning a while ago about fuse placement and safety. Now I could be wrong about some of this, my memory isn't the best.

    So here is the power section of the schematic with some added info about the wire colors:

    [​IMG]

    Initially I thought I could just swap out the cable and put the green to ground. But I came across this for 3 prong conversion on Fenders:

    [​IMG]

    This is all fine, but I thought I remembered that you are supposed to have the fuse and switch on the "white" wire for safety reasons.

    Can I get some clarification on this?

    Also, how do I deal with that Phase Reverse switch? I haven't run into that before.
     
  2. zachomega

    zachomega Member

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    Oct 21, 2005
    Location:
    Bucks County/Philadelphia PA
    Fuse and switch should be on the hot wire. In this case, hot is black. White is neutral. This all of course doesn't matter if your house outlet is wired wrong. You'd be shocked (and possibly literally) to find out how often this is done incorrectly. Spend 10$ and buy an outlet checker from Home Depot to double check.
    Good luck!

    -Zach Omega
     
  3. aortizjr

    aortizjr Member

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    Joined:
    Nov 24, 2004
    Location:
    Santa Fe, NM
    Well not only that, but other houses, venues, etc.
     
  4. zachomega

    zachomega Member

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    Oct 21, 2005
    Location:
    Bucks County/Philadelphia PA
    Don't get too caught up in it. If the amp is built properly, you won't have any problems. If the amp is an AC/DC model, then you have to watch out. In the case of the Sunn, just add the cord as stated with black to the switches. This is just an extra level of protection.

    -Zach Omega
     
  5. tonezoneonline

    tonezoneonline Member

    Messages:
    437
    Joined:
    Dec 15, 2003
    Location:
    central Illinois
    Connect your green wire to a good chassis ground.I usually use a lug on the power transformer bolt and disconnect the phase reverse switch.Last Sunn head I had the standby switch went out so I used the polarity switch for that.Nice to have a spare sometimes.
     

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