Schematic taken from Nelson Pass „First Watt“ Website. Parts designation same as used in the description from the pdf.
Each power rail got 94.000µF, a stereo amp have all together 376.000µF.
Star grounding on PCB to one GND point.
mounting RG178 without connector on the PCB:
Fabric protective sleeve or shrinking tube is needed to mount the ptc thermistors.
use a little bit thermal grease between the two transistors. Hold them together with a cable tie or better take a stripe metal.
Heat sink, ~0,2K/W:
Improvement of the coupling between Mosfet and PTC resistor with a copper platelet. 15x15x2mm: