The schematic we propose offers a less harmonic signal and a supplementary gain, so it get rid of those annoying variation between speech and music wich offen appears at radio and tv. This automatic gain volume control schematic need a +-15V power supply and 6mA.
Bellow you get the volume agc circuit pcb, graphic and schematic.

This simple mosfet power audio amplifier circuit, with TL071C and 2 mosfet power amplifiers can deliver up to 45W on 8 ohm.
This schematic is based on Siliconix application and is based on variations of voltage on the 2 resistors serial inserted on the voltage supplier of the operational amplifier driver.
The MosFet transistor must be mounted on a heatsink at least 1K/W.