Page 1 of 3. www.allen-heath.com. PA-CP System Block Diagram. +. -. GAIN. LM HM HF. 4 BAND EQUALISER. MONO CHANNEL. 100Hz. MIC IN. PP. FADER. PFL. PEAK. STEREO CHANNEL. FX. AUX. FB2. FB1. LF. ST2/4. R. L. R. L. GAIN. ST1/3. +. +. -. LINE IN. +48V. INSERT. MUTE. PAN. DIR OUT. GAIN. LR. SUM HF.