Hi Dave, welcome to the forum!
You will need a 7.5V, at least 1 amp regulated (stabilized) DC power supply. This adds up to at least 7.5W. Make sure the power supply is connected with the negative pole inside the plug, which is the opposite of just about any modern kit! Multipurpose power supplies that have a number of alternative DC plugs will usually have one that fits the Beolit.
Otherwise there's no specific voodoo in the Beopower, the Beolit 1000 eats DC just like any other similar device.