Gian, I7SWX, has shared a mod for replacing the TDA2822 audio amplifier. He intends to apply this circuit after other mods he is experimenting with on his uBITX.

The audio PA is the TDA2003, an amplifier where the bandwidth can be modified.  His circuit is designed for 3kHz.

This circuit, with reduced bandwidth, has been tried on an FT920.  It is possible that some components values may need to be changed.
It is important to note that Gian has not tried this mod as yet, but others might like to beat him to it!

Reference