I have a 2005 XC90 with a 6 disc premier 8 speaker factory unit. Does anyone know if/how many preamp outputs there are? There should be at least one for the factory amp under the front passenger seat. But I don't want to assume how it is connected to the factory head unit. I'd like to add another amp to the factory head unit to power a couple of subs in the rear. I'd like to know if there is an additional preamp output for this.

Any help is appreciated.

 

Nope - no pre-amp outs. It's optical connection anyway. Somewhere by spare tire you can find rear speakers output wires, and take the signal from there.

 

That's actually a big help. Thanks.