Patent ID: 7167569

Claim:
An apparatus for automatically determining a type of each load coupled to an amplified A channel signal and an amplified B channel signal and automatically configuring the amplification of the A and B channel signals to drive each determined load type, comprising: a first configuration of amplifiers, comprising a first amplifier (A 1 ) and a second amplifier (A 2 ), ace arranged to generate an amplified A channel signal between a first output of the first amplifier (OUTA 1 ) and a second output of the second amplifier (OUTA 2 ), wherein the first and second outputs (OUTA 1 , OUTA 2 ) are adapted for driving a load of a first type coupled there between, and a third amplifier (B 1 ) and a fourth amplifier (B 2 ) are arranged to generate an amplified B channel signal between a third output of the third amplifier (OUTB 1 ) and a fourth output of the fourth amplifier (OUTB 2 ), wherein the third and fourth outputs (OUTA 1 , OUTB 2 ), are adapted for driving another load of the first type coupled there between; a second configuration of the amplifiers comprising the first and second amplifiers (A 1 , A 2 ) arranged to generate the amplified A channel signal between the first and second outputs (OUTA 1 , OUTA 2 ), wherein the first and second outputs (OUTA 1 , OUTA 2 ) are adapted for driving a load of a second type coupled there between, wherein the first type is different from the second type, and the second amplifier (A 2 ) and the third amplifier B 1 are arranged to generate the amplified B channel signal between the second output (OUTA 2 ) and the third output (OUTB 1 ), wherein the second and third outputs (OUTA 2 , OUTB 1 ) are adapted for driving another load of the second type coupled there between; a control circuit that automatically determines the type of loads coupled to the amplified A and B channel signals and automatically employs the determined load type to select an arrangement of the amplifiers in one of the first configuration and the second configuration, wherein the selected arrangement of amplifiers provides an appropriate level for the amplified A and B channel signals to drive their respective loads; and a switch (SWA 3 ) that is arranged to: couple the first output of the first amplifier (OUTA 1 ) to an input of the second amplifier (INA 2 ) when in a closed position, and disconnect the first output of the first amplifier (OUTA 1 ) from the input of the second amplifier (INA 2 ) when in an open position, wherein the switch (SWA 3 ) is selectively controlled by the control circuit such that the switch (SWA 3 ) is closed when the selected arrangement of the amplifiers is the first configuration, and the switch (SWA 3 ) is open when the selected arrangement is the second configuration.