Normally the 8 ohm tap would be correct but:
The 8 ohm tap will output 2x the voltage but 1/2 the current as the 4 ohm tap. However speakers impedence is not purely resistive and depending on the impedence vs freq. profile of your speakers, the 4 ohm tap might be better. Try both (as long as you don't listen too loud) to see which sounds best to you.
The 8 ohm tap will output 2x the voltage but 1/2 the current as the 4 ohm tap. However speakers impedence is not purely resistive and depending on the impedence vs freq. profile of your speakers, the 4 ohm tap might be better. Try both (as long as you don't listen too loud) to see which sounds best to you.