Different sources...
...have different output levels...Music from different sources(AM/FM, tape, vinyl, CD) usually exhibit volume differences; there seems to be no standards for output voltages...For whatever reason, perhaps it's just not as noticeable with tunes...heck, I have to adjust the volume of my lil' ol' not-part-of-an-HT-system tee-vee depending on the source: broadcast, VCR or DVD...dat's why the good Lord done gived us re-motes!
jimHJJ(...Hey mark! how are things?...)