Audible dif btween comp/deck output V?

The answer to your question is yes there is an audible difference between a computer and a audio cd player, generally speaking computer outputs are low voltage and high impedance, they are designed to be a computer first and not an audio source. Between brands there is a drastic difference in sound quality and preout voltages. Very very few of the cd payers that claim a 4 volt or 5 volt preout actually make that much clean voltage, they generally have a high output impedance and clipping preouts. One of the few cd players that have actually made what they claimed is Eclipse, they generally have a true 8volt rms non clipping (0db) preout at a low 55ohm impedance, this is part of the reason why an Eclipse is a little more than evey one else. The lower the impedance, generally speaking the better the sq, the tradeoff is immunity to noise, it costs Eclipse more $ to keep the noise out and maintain SQ. A non clipping preout gives you just that, a cd player that can play to full output and not distort the audio signal, again this costs more $ and most companies will not pursue an audio signal to this length. It is well worth your time to listen to a cd player like a Kenwood and then install a 5volt Eclipse in the same vehicle on the same system, your ears will tell you the rest.