The FP-PA20B features a balanced line level input that may be connected unbalanced. A front panel gain control is designed to be adjusted either manually or with a trimming screwdriver. The gain range will accommodate standard unbalanced levels as well as professional balanced levels. A 25 V amplified output is provided to drive corresponding speakers in a distributed sound system. Audio levels that could cause the amplified output to clip are compressed using two dynamic time constants designed to preserve aural transparency. Normal audio level signals remain unaffected by the compressor thereby preserving audio dynamics and preventing the compressor from increasing feedback potential when the amplifier is used for paging. The FP-PA20B produces average audio levels and audio clarity normally expected of amplifiers delivering much higher output power.