I decided to build a new audio amplifier, based on the popular NE5532 opamp. I chose a class AB circuit because it’s simple and does not consume much power.
The basic concept was the build a power stage after the NE5532 opamp. Because I don’t have a subwoofer, I added a basboost filter in the feedback network.
The input is AC coupled and a RF-filter is added to the input.
With the resistor bias, you can adjust the quiscent current, so you can determine whether it must operate in class B or in class AB. More quiscent current means less distortion, but more power consumption.
The amplifier works fine. With the jumper you can also decide to use a +6dB bass boost circuit (not included in LTspice schematic).