Well, after one more evening experimenting with different configurations (switching power, sound & idecables I think I can tell you my final opinion on the Asus 52/24/52 (CRW-5224 A).
It’s as you say a playback problem or better said a poor drive for audioplayback.
The Philips PCRW 404 is an internal ide writer (old skool max. 4 times writing speed). But when it comes to audioplayback it beats the new ASUS hands down. I used a very dynamic audiocd, and listened with a Beyer Dynamic headphone, only using the frontjacks (to make sure it was not a soundcard problem). The ASUS in audioplayback mode sounds very flimpsy, and their is a lot of harmonical distortion going on, very noticeble when you crank up the volume. The Philips however, even at loud frontjackvolume sounds clear and full. When listening to both drives thru the soundcard, the problem for the ASUS is even more noticeble, especially when you got 3D enhancers working.
To be sure, I switched the drives of position (may’be their was an interference problem going on from the power block of the computer), but this didn’t change the poor audioplayback of the ASUS.
Could it be that in order to win the speed writing race, ASUS has a problem shielding the drive (I mean the high-powered drive mechanism interferes with the audioplayback?) or have cut costs on the audioplayback? Four days ago I wrote in to the ASUS helpdesk, but they stay silent.
ASUS: makes a great job of fast burning, but when you want to use this drive as an audioplayback drive, you’d better look somewhere else.
Thx for writing in.