Bray, if you want to pursue it, I'd suggest temporarily physically disconnecting the Toslink and 6-ch analog cables to ensure the Phillips player is truly using 2-ch analog. Lacking that, at least disable digital out and 6-ch analog out in the player menu system.
For troubleshooting, make sure your receiver's 6-ch analog input is not activated.
My Sony DVP-685V 5-disc DVD/SACD changer is similar to your Phillips. If I accidently have 6-ch analog selected (on the receiver) when playing non-SACD discs it doesn't sound as good.
Also re-check all the other menu options. These players are complicated and some little nuance like "night mode", bass management, etc could throw off the sound.
In most cases the difference in sound is a player or receiver config issue, not an intrinsic difference in player sound quality.
