audio amplifier with two inputs

Subject: Design an audio amplifier with two inputs (at least one of them is a microphone) and two outputs (2x3W speakers).

Requirements and Limitations:

Inputs should be able to be controlled independently. For example, while the volume of audio input one is turned down, the volume of audio input two should not decrease.

More than one operation should be possible on the audio.

The use of special-purpose integrated circuits (for example TDA2050) and microcontrollers is forbidden!