Ampeg PF-20T, PF-50T: adapting to international power

Discussion in 'Amps and Cabs [BG]' started by Swiss Frank, Sep 15, 2019.

  1. Swiss Frank

    Swiss Frank

    Dec 29, 2016
    I've seen photos of the PF-50T main board that claim that using the amp at 100V (Japan, where I live), 120V (North America) or 240V (Europe) is just a matter of moving one cable between three sockets.

    1) Can anyone confirm? Have you actually done so or you just have heard this works?

    2) Is the PF-20T the same story?
  2. Wasnex


    Dec 25, 2011

    @disssa has images of the circuit cards for both amps posted on his site. I see two sockets on the PF50T, Ampeg PortaFlex PF-50T but there is a third plug is concealed below the wires.

    Here is a post that shows all three of the plugs. HOT AMPEG NEWS! PF20T, PF50T, PF112HLF

    Depending upon which voltage the amp is setup for, you may need to change the mains fuse. See image below:

    The PF20t circuit board does not have the extra connectors like the PF50t Ampeg PortaFlex PF-20T

    This Wiki says, the PF20T can be setup for different voltages by moving spade connectors on a circuit card. Wiring configurations for 100V, 120V, and 220V are listed. Technical - Amplifier | A fuse change may be required just like with the PF50T.

    It's also a good idea to check the bias of the output tubes whenever an amp is used with a different voltage.
    Last edited: Sep 15, 2019
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  3. Swiss Frank

    Swiss Frank

    Dec 29, 2016
    Thanks Wasnex. If I decide to get one of the PFs, I was already leaning for the 50W just for the greater tone control. Ease of switching power makes it yet more appealing.
  4. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
    Always check before assuming anything. It's common for there to be changes in production that can make a previously (and accurately) assumed fact incorrect in earlier or later production units.
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