I'm currently rocking a Pioneer SX-50, which works and sounds great. It's almost 40 years old, and I'm wanting to replace the filter caps just for reliability reasons. I have a pair of Nichicon's coming in next week, and I've heard about AK'ers adjusting their bias after a recap. Should I be checking my bias after I change out the filter caps? This is my first time recapping, and I'm just worried that I might blow something up or electrocute myself when adjusting the bias.
Is it necessary to adjust the bias after replacing filter caps?
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If the original supply rail caps are working and you replace them with new ones, that will not have any effect on the bias settings (quiescent current and offset voltage). The supply voltage will not change with the recapping, and that's the only thing that could possibly require a readjustment. Your AC line voltage varies a bit throughout the day and that does not cause any need for a readjustment. Where you would need to check the bias settings is if you replace electrolytic coupling caps in the power amp itself, if it is uses caps to do the coupling. A leaker there replaced with a nice new one could affect the DC setpoint.
