Clone resistor mixer configuration varies per clone:

330 Ohm (331) Resistor -> CPU sound marked R4 on N8
2.2 Ohm (2R2) Resistor -> Expansion Audio marked R3 on N8

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Original N8 resistor mixer configuration:

470 Ohm (471) Resistor -> CPU sound marked R4 on N8
18 Giga Ohm (189) Resistor -> Expansion Audio marked R3 on N8

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To fix expansion audio issue being too quiet on certain famiclones(60-pin versions), you must replace a couple of in series audio mixer resistors close to the notch(screwhole frame) found at the center of the n8.
What worked so far is replacing both with two 4.7K ohm resistors(SMD resistor 472 package type is 0603[1.5 mm x 0.8 mm]).
