Better sound through Bluetooth and Line-in than USB drive?

[OilPatch]

Slightly off topic but I'm curious to know what I should do for best sound quality(I plan on having Noah seriously upgrade the sound system but keep the oem head unit). I have a MacBook Pro so all of my music is stored via iTunes and almost all of it was purchased thru iTunes with a few CDs here and there that I would load on to itunes. I read a thread on here about converting the quality of your music with various programs that will convert the file, my question is should I do something like that then save it all to a thumb drive for the best possible music playback with our stock head unit or do y'all recommend another course of action?

Link on the thread I was referencing:

http://www.fordraptorforum.com/f12/myford-touch-external-drives-lossless-audio-19772/

 

[txcomp]

One question I would have is where does the D/A conversion actually take place?? Is the signal going to the amp still digital or is it already analog?? If I had to guess, it's most likely done in the head unit and as already stated, likely in a very inexpensive chipset.

I haven't really pulled my truck apart to look/measure but maybe some others have?? I would like to eliminate the factory amp and it's DSP completely in my build but I'd guess that there are signals like the nav directions, etc that have to flow thru the factory amp.