@ceaser, there's something wrong - either with your A570 or your amplifier - the A570 should give a perfectly good and strong CD audio line output. The A500/500+ on the other hand, throws several volts out so in comparison the CD level is low in the mix, but you aren't really meant to feed those sort of levels into audio amplifiers.
Also, have you got the volume control turned up for the headphone jack? (it isn't just an on/off disable switch).
