There are fill schematics and board layout for this powerful DIY amplifier that is based on the LM3886 chip. Looks like it is built like a tank.

“This amp is based on the PA100 parallel amplifier detailed in National Semiconductor’s application note - AN1192. This amp uses two LM3886 per channel, in parallel circuit. This amp can deliver about 50W into a 8-ohm speaker and 100W into a 4-ohm speaker. Can a chip amp sound good? Definitely! Jeff Rowland uses LM3886 in some of their designs, and they received good reviews.”