Convert new GK MB200 110V to 240V

Discussion in 'Amps and Cabs [BG]' started by Groove Doctor, Sep 22, 2016.

  1. Just need some clarification....

    I've been following the thread for converting an MB500, bought a new MB200 (Sam Ash heavily discounted)... BUT.... the MB200 is different inside.

    Can somebody clarify what I'll need to do to switch a 110V model to use in Australia 220-240V?

    Or, is it rated for both voltages? Just labelled for 110V?? (hence, safe to use at 240V as is??)

    Gut shot

    Clip (vertical) to the left of 230v/115v lettering.
    Last edited: Sep 22, 2016
  2. Black circle (fuse?) T2.5A 250V

    Power switch 8A/128AH (?)

  3. What's this screw?? Fine adjuster?
    Positioned in a line between bass and Lo mid knobs.
  4. Can you get a better angle on the clip 110/240? Yours appears different from mine, since sold.

    Iirc there was a black plastic covered jumping wire clip which I moved over to the opposite position retaining the central pin. It was holding on tight. I fashioned a hook from a paper clip by work hardening and snipping it just so.
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  5. Whatever you do, don't plug it into 240v without first sorting the internal voltage jumper!

    The fuse doesn't need changing. From memory I don't think it is swappable anyway.
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  6. I'm away until Sunday.

    Bottom left corner (next to power input). I'll send it thru ASAP.
  7. I don't know what you are looking at but first pic of post #2, says 115 250 on the board. The black plastic doofer pulls off and you shift it onto the next pin. Job done.

    I made the hook because I feared crushing the doofer with pliers. Fingers couldn't get a good enough grip on it. It took quite a pull with the hook.
    Last edited: Sep 23, 2016
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  8. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    there should be three pins under the jumper, after you pull it off
    right now it's on the bottom two, just shift it to the top two
    (what you're calling a clip is normally called a jumper)
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  9. Here's a close up....


    So there's just the one jumper to change and that's it?? Ready for 230V ??
  10. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

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  11. ThisBass


    Aug 29, 2012
    Didn't read the engineering datasheet for the ICEpower50ASX2 but I'm pretty sure the B&O documents refere to this point.
  12. That's how it worked on mine.

    The light on the front can give you a fright taking it's sweet time going from red to blue on powering up.
  13. Dead easy. I'll let you guys know how it goes.

    The Fuse.... should that be changed too? Or is it fine to stay as is = 250V 2.5A
  14. Fuse fine.
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  15. Jumper in new position...
  16. No ICE cable?
  17. kumimajava


    May 19, 2010
    Tokyo, Japan
    @Groove Doctor

    Sorry to be reviving this thread - but i'm in a similar position (currently living in Japan/100v, and may at somepoint move back to Europe/230v).

    Did the jumper-switch work? did the amp function normally thereafter, or were there fireworks?

    The labelling on the version I have is very adamantly saying "100V only operation", but the circuitboard looks the same, including the 115/230 jumper

    Thanks in advance to anyone who could confirm :)
  18. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    There may be additional control circuitry on the preamp board to support 100V operation. This is not uncommon. You might ask GK.
  19. kumimajava


    May 19, 2010
    Tokyo, Japan
    May be a good idea to shoot GK a message, but I doubt there's anything special inside... when I opened the case of the amp, it looked the same as what was posted above. (something was rattling inside, so I had a look - turns out it was a just an old sticker that had been attached to the inner casing, but the glue had let go).

    Apologies regarding the confusing info re: 100v operation. That was attached to one of the stickers outside, but on a different MB-200 (I have two, both original 'bought in Japan' spec).

    What particularly confuses me is this.

    On the back of the amp we've got this marking:

    And on the top of the casing:

    I'm not sure what to make of this?

    Back input says: 100-120v 50/60Hz.
    (so this makes me think that there is no 'Japan specific' circuitry vs the US model)

    Top says: 120V 60Hz ONLY

    ... and I've been running these in Tokyo on 100V 50Hz and of course it's been fine.

    On the other hand, I've heard horror-stories of someone plugging in US-spec electronics into the Japanese mains (e.g. pedalboard + power supply), and gotten 'magic smoke' and everything burned out.

    Is this just matter of various certification standards?
  20. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    It depends. That's why I suggested that you contact GK.