This is the best one I have found LM3886 in a TO-220 package 11 pin IC. Output is 68 watts with a 4 ohm speaker, 38 watts with a 8 ohm speaker, 135 watts peak to peak. Circuit is very simple and you have several choices to build it. Signal to noice ratio is 92 dB. Feedback capacitor high pass roll off Fc = 1 / (2 pi R1 C1). Optional mute capacitor. Rm = Mute Resistor allows .5 ma at pin 8. I will have to find the circuit to this it is extremely easy to build it only required a few parts and you can build it stereo too. I bought 20 of these ICs they are dirt cheap I beleive the price was about $2 each 20 years ago.