I temorarily added a filter capacitor to reduce hum from my battery charger. Those higher wattage resistors are replacing a trimmer potentiometer.
Here is the old trimmer potentiometer that adjust the output transistor bias current. It is dead. Looked on Digikey, apparently this type is no longer being made. I can just pick and choose fixed resistors to get the bias correct or find another potentiometer that would work. This is a 125 Ohm potentiometer.
Control shaft detail
Found a pot at Newark for $11.14. Not exact fit but a better part and it will do the job well: