Loudspeaker coupling circuit for power amplifier end stage - uses 2 power lines and 2 measuring lines for positive and negative loudspeaker signals

摘要

The circuit has an end stage amplifier output coupled to a positive loudspeaker terminal. Its negative terminal is coupled to the earth of the supply network for the end stage amplifier (2). The positive terminal of the loudspeaker (1) is coupled to a positive measuring line with a feedback resistor (R9) connected between the amplifier output and its negative input. A negative measuring line is connected to the negative terminal of the loudspeaker connected to the negative input (4) of the end stage, which is connected to the negative input of the amplifier via a pre-resistance (R8). An input resistance (R10) is connected between the end stage positive and negative inputs (3,4). The coupling between the end stage and the loudspeaker is provided by a 4-line technique with 2 power lines and 2 measuring lines. ADVANTAGE - Prevents attenuation in upper frequency range at high power levels.