The power supply for the US/Japan Macintosh Classic is 110V only. It cannot be switched to 220V. The power supply for the International Macintosh Classic is 220V only. There are different components installed on each power supply.
Modifying the power supply by changing the JP1 jumper to work within a different voltage is definitely not recommended and will void the warranty.
Article Change History:
29 Nov 1994 -
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