Excuse me for digging this up from the past, but just couple of points in the interests of future readers, it being a wiki
In the wiki, it says two 680 ohm resistors but looking at an earlier 5k amp board, it looks like there's one 680 ohm and one 330 ohm.
The replacement suggested in the wiki is a "typical" resistor, whereas earlier 5ks has wire wound ceramic types. A smiley face 5k seems to have a "typical" resistor but it doesn't look like 680 to my untrained eye. The ceramic is 4W and suggested replacement looks like 2.
Any comments from the EEs out there (apart from get an expert to do it...)?