Archive of the former Yahoo!Groups mailing list: Vintage Simmons Drums (UK) Users Group

the SDS 1000 has the later Simmons standard PSU which is designed for 110/240 volts.

There are some pins on the PSU board with wire links. You need to cut the 2 links that put the transformer primaries in parallel and join the 1 link to put them in series for 240v. I can't remember which, but if you remove the board from the unit you can trace the connections on the PCB.

Hope that helps?