An excellent alternative power supply for the MK1 and the Octatrack is the iConnectivity iConnectMIDI2+ power supply.
It is bi-volt (110-220) and outputs 6v 3a, it also has a small footprint, and I found it in many places to buy as accessory.
[http://www.iconnectivity.com/products/accessories/6V18W-power-transformer](http://DC Plug Type: 2.1mm ID x 5.5mm OD, Positive Center, Barrel length 12mm.)
Just check the plug type because I´m not sure about the MK1:
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[li]DC Plug Type: 2.1mm ID x 5.5mm OD, Positive Center, Barrel length 12mm.[/li]
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Sorry! Thought the MK1 was DC and it is AC