Jeep Grand Cherokee 03 - Using stock infinity amp to carpc
I've been reading around on here through many threads and I've done a load of searching through google (dont all the posts seem to start that way!), but I'm having trouble working out my audio setup, and wondered if someone could provide some insight as to a preamp I should be looking at.
What I currently have is the Jeep premium factory audio system which comprises of four door speakers and two tweeters in the dash. These are powered by an infinity amp, which is connected to the factory HU - http://www.wjjeeps.com/infinitysys_2.jpg. I am not keeping the HU, so the PC is replacing this, but I am happy with the audio quality from the rest of the system (my ears arent tuned for super high quality audio!) and ideally I dont want to invest in a new amp if I can help it. The HU currently supplies four +/- lines to the amp (is this considered four channels?), and the amp in turn outputs to the 6 speakers. A diagram of this is at http://www.wjjeeps.com/radio_systemdiag1.jpg.
I'm happy to splice into the cables running to the amp, but from reading other postings with similar cars/audio setups, the problem is that the stock amp needs a high level input, so the output from the pc directly is line level and thus too low, resulting in low audio out of the speakers. The amp has no controls or connectors other than the factory wiring loom, so I have no way to change the amp settings.
My motherboard has onboard 6 independent 3.5mm outputs, as well as a SPDIF (optical and rca), so I would like to take the audio from one of these sources, into my stock amp.
I believe I need a preamp or line driver (i'm not an expert on audio so using words I've picked up from the forums, please correct me if i'm wrong!) of some sort to ramp up the level from the PC to something higher, but this is where I am a bit unsure of what to look for, so from looking could anyone comment on these:
In terms of layout I'm guessing it would be:
PC > Preamp > Stock Amp > Speakers
If none of the things I have mentioned above are suitable, could anyone make some recommendations on what I should look at? Sorry for such a long posting.
Thank you very much in advance