On that C8, I been given 47nF cap (473), I thought I better look it up myself, 47pF would be 470 on the capacitor. There is more, 47nF is correct as in the link:- https://electronics.stackexchange.com/questions/71727/why-is-my-audio-amp-picking-up-am-and-fm-radio-stations
“Production amplifiers usually include a Boucherot Cell on the output, often an output inductor after that. Both of these devices can help block incoming RF, even though it’s not their main function. The Boucherot cell is simply a capacitor in series with a resistor, placed between the output and ground. Common values are 0.1uF and 10 ohms. You can see this in many amplifier schematics. Edit: I see there is a 10 ohm/0.047uF cell in the amplifier”.
0.047uF is 47nF.
and C9 doesn’t exist on BOM in PDF, should have been C8 as 47nF
Hope this helps?