You can't use a sub with what you have unless it has jumpers between pre-amp and power amp.
There is no service manual available for your Outlaw that I can find. So there is no point in paying money to a service center. You can't service anything without a service manual and as far as I can tell none was ever released. So only Outlaw can fix it. That unit was not on the market long, so I suspect they were a problem prone unit.
Don't buy that sub it will be junk.
