VLP series amplifier allows to use two types of input connector per channel, XLRjack for balanced connections and 1/4-inch female jack that will accept balanced and unbalanced connectors. Use these connections to connect output signal from mixer, cross-over or EQ to VLP Series amplifier. Balanced connection is recommended for cable runs longer that 20ft. When constructing own XLR cables follow pin configuration describe below for proper connections. For cable runs shorter than 20ft may choose the 1/4-inch unbalanced input option. 1/4-inch unbalanced input option may be more convenient for most users due to abundant supply of prefabricated cables available at local audio dealer.