Design base for this PCB was National Semiconductors AN-1849 application note.
This is a typical configuration used in audio power amplifiers with some extra R3/C5 and R4/C6 (snubber) elements connected in parallel with the filter capacitors (C3 and C4). The role of these elements is to reduce the impedance of filter capacitors.
Resistors R1 and R2 are slowly discharging large reservoir capacitors in the case of disconnection of power (they don’t have to be assembled). Connecting them with relay, only when supply voltage falls below some level, would be a better solution.
Pad G or, by mounting a Rg resistor a little higher, the assembly hole may be used to connect supply PCB with the enclosure ground.
Some elements have been provided with few more pads. As a result it is easier to mount components in different enclosures. Additional soldering points (+) and (-) can be used to connect an external bridge. Two types of C1 and C2 may be used – there is enough space for two 35mm (10mm snap-in) or four 18mm (7.5 mm spacing) diameter capacitors.
As you can see there is no space for fuses (therefore this PCB is smaller) so I have to place them somewhere between supply and amplifier PCB.
