I just got an old 4x4 and found an old sony 60x2 amp under the seat. I am putting an older alpine HU in it and wanted to use the amp to power the 6x9s in the doors. The amp does not have any rca inputs. I know that is what the high level inputs are for--connect the amp directly to the speaker outputs on a HU. However, I remember being told(or from first hand experience, can't remember which now) that you could not hook up high power HUs to the high level inputs on an amp. I did some searching and could not find any threads that addressed this topic specifically. The alpine HU in question has 25 watts per channel. Anyone have any experience with this or know the answer?