How do I connect a powered sub-woofer to an older two-piece (amplifier & tuner) with no pre-amp output? The amp has no pre-amp, the sub has no speaker level inputs. I bought this setup from someone who had it all hooked up together. We just unhooked it, I never checked out how he had it hooked up. When I got it home, I can't figure out how it could have possibly worked. So the amp has no pre-amp output and the sub has no speaker-level inputs, can I make some kind of wire, or is this impossible? I saw it running, it worked for someone...but he moved out of the country is why I can't ask him! Thanks!!