The FlexPwr Brick™ is designed to function properly with an input power of 10-28VAC (ungrounded) or 12-32V DC (grounded or ungrounded). A 2-pin header (Phoenix Contact #1881448)style connector is used for the power input. The 12VAC, 600mA wall transformer provided with the product provides a floating power source that has been designed to eliminate any ground loops through the power supply connection. The input for this product consists of a loop-thru input with two RCA/Terminal Block connectors. An audio signal with excessive DC component (or offset) will cause the VAC Brick to malfunction. The audio signal needs to be within -4V to +4V. The VAC Brick hastwo audio outputs consisting of RCA/Terminal Block connectors. Unused outputs do not need to be terminated for proper operation of the Brick.