Digital audio signal processing circuit TDA7449

Shown is a typical digital audio signal processing circuit. The main body of the circuit is TDA7449. In this circuit, the audio signals input from jacks J3 and
J2 or interfaces J4 and Jl are respectively sent to the @ pin, @ pin and @ pin, ⑦ pin of TDA7449 through the coupling
capacitor internal volume tone (treble, treble, After adjustment and processing, the @ pin outputs the left channel audio signal, and the ④ pin outputs the right channel audio
signal, and finally sends it to multiple output jacks or interfaces.