I am not sure about the specification of the DVP 542K. Most DVD players will have a Audio Out labelled L & R. In some players they will be labelled as Front/Mixed. If you are using the front L & R, these are the right connections for two channel audio.
Well, the Philips also has a DAC, and that is how you are listening to music and movie sound.
What we are discussing here is improving the sound.
External DACs are made for two channel audio, and will certainly work on the Front L & R of movies. The idea is that DVD players and ordinary CD Players do not spend too much money on the DAC and that is why they lose out. Connected to an external DAC, the sound will have more soundstage and clarity The reason that people use a CDP for two channel music is that it does not have the electronics that are needed for video and will have play the CD music better.
As I said you should get an external DAC, connect it between your DVD Player and amp, and see if the resulting sound is good. It will be. After that, when the audio bugs hits you again, you can buy a CD separately to get even better music.
But remember most external DACs process only two channels.
By reading the specs and asking the dealer or retailer. Alternatively, you can give the specs to this forum and we can confirm whether the equipment is analogue or digital. Most branded equipment will have digital to analogue conversion. Craftel does not have as they have not yet entered the digital domain, and makes amplifiers that just amplify analogue signals.