What is the affects of the different Volts on pre-amp outputs. Does it affect the sound quality? The loudness? The distortion? Would 2 be any different than 2.5? Would 5 be worth the extra money? Why do most companies only have 2 and 2.5? I am just very confused on this whole issue and would appreciate it if someone would give me some good details on this subject. Also what are some of the better Head Units if I only want MP3 capability and decent sound controls for a good price. Not worreid about the Amp in it since I am hooking up my speakers to an external amp.
good line voltages don't make the system any louder, but they do make for a cleaner signal at the other end of the cable, and they can increase resolution since you'll get more detail in a wider signal band. usually 4V is about ideal, and the amp inputs have to be matched to teh line voltage for ideal performance. over 4V and many amps can't accept the signal without being overdriven. lower than 4V and you lose the benefits of the stronger voltage.
Yea the higher the pre out signal from the headunit the cleaner the signal sent to the amp. Therefore makes the amp works less as it lets you keep the gains down on the amp meaning more efficency.