=parapaul;12824895]As an aside, I had an email from Car Audio Direct - who really know their stuff - and they suggest that the JL XD amps are no different to any other amp. Once an RCA connection is made, the line becomes unbalanced.
This is quite interesting to read as I am in a similar boat as I plan to use a wiring harness behind the HU with the HU coded to HiFi. I am/was under the impression you can only use certain amps that accept differential balanced inputs otherwsie suffer from a loit of noise - this puts me way off my budget for amps.
As all i wanted to do was feed a bit more power to the speakers/subs without spending too much. But when you look at amps that accept diff balanced inputs they are in the region of £350+