Mono bridging a stereo amplifier allows the left and right channels of the amplifier to go to a single speaker thereby doubling the wattage applied to that speaker. Some Yamaha stereo amplifiers such as the P2200, P2201, A100A, and the XH150 do not have a built-in system for bridging their stereo amplifiers across a single load. Despite this limitation it is possible to mono bridge a stereo amplifier that is not equipped with a bridging capability by splitting the signal which feeds both amplifier inputs and reversing the polarity of one of the signals. This can be accomplished through the use of a balancing transformer found in most HI-Z to LO-Z passive convertor boxes.
- Connect the input source signal to the primary side of the balancing transformer.
- Connect the 0 degree polarity signal (Normal Phase) on the secondary side of the balancing transformer to the input for channel 'A' on the amplifier.
- Connect the 180 degree reversed polarity signal on the secondary side of the balancing transformer to the input for channel 'B' on the amplifier.
- Connect the ( + ) output of channel 'A' to the speaker's ( + ) input.
- Connect the ( + ) output of channel 'B' to the speaker's ( - ) input.
NOTE: When bridging a stereo amplifier the ground connections (black) of the output are ignored.