pHEnomIC

iTrader: (14)

I notice some head units have 24 bit dac and some only have 1 bit, how much sound quality are we talking about here?

Also I noticed the pre-out voltage varies quite a bit on headunits. Whats the difference between a 2.5v pre out and a 6v pre out? I dont think it would matter much if you have an amplifier. Or does it?

M-ManLA

Pre-Amp output pretty much makes the signal much stronger to the amps for less distortion. DAC stands for Digital to Analog Converter. Pretty much it is taking the digital information (1s and 0s), and convert them to analog (audio) signal for your speakers. mostly all CD players have a 24 bit DAC now.

WhiteBird00

iTrader: (4)

Actually, higher pre-amp output voltage will tend to increase distortion but is used in car audio to overcome extraneous noise. Home audio systems run low pre-amp voltage for reduced distortion but they don't have to run in the "noisy" environment (electrically) of a car. The trade-off is to use higher voltage to overcome noise problems at the risk of a slightly higher level of distortion (although still low enough to be virtually inaudible).

M-ManLA

Yea pretty much what I was trying to say.

WS6Drop

iTrader: (10)

I would get HU with Burr Brown DACS if possible, usually the ones for SQ are setup this way. You also need to watch using a HU with high preamp out voltages on older amps as the input circuit wasnt designed to for this and will cook the inputs of the amp.