I have an eD nine.1 and it goes from 150mv-7volts for the gain. My HU is a pioneer premier deh-p8mp that has 6.5 volt pre-outs. Does that mean i set the gain almost all the way up?
If your amp goes from 150mv-7volts for the gain and your head unit is 6.5 volt. Yes the gain should be about 3/4. I would set it 1/2 because the 6.5 volts from the head unit is at full volume.