I picked up a Bose 4401 preamp from a foreign seller on the auction site . The ad stated it was fully funtional and it was 120 volt U.S model.I connected it to my Bose 1801 and I only get sound out of the right channel and I have to crank the volume close to the max to get an average level of sound. when I do this the sound becomes distorted .I am thinking maybe it might have been converted to 220 volt hence the reason for having to put it up to maximum volume . I took a look at the bose 4401 service manual and it has schematics on how to convert it 220 but they are not really that clear in the illustration .Does anyone have any thoughts?