Or look into an amp that excepts high level inputs. I've never used one but if you are gonna use the high level inputs, why spend money to do so.
David Navone makes a competition level Hi/lo converter that is supposed to work pretty well. I've been out of audio for a while but I'm sure if you google that name you will get a web page for him or something.
try this link:
David Navone - About Navone Engineering - Car Audio Engineering
I can't access it from work :-(
