Looks like we've all been good boys and girls this year ... Santa drooped some AKG450s off for me too. Still in box as of today. Too full from Christmas dinner to plug them in.
Get them plugged in, Doctor Who is over and it's now the missus' time - Strictly and Downton. Hence I'm on the PC playing World of Tanks and listening to Sigur Ros!
Pleased you've warmed to them. The placement for you must be the small cups. I'm using them only for portable use (iPod Classic) as I have Senn HD202s (cracking for £20 odd and beat my HD380 Pros for SQ).
Do you mean directly into the headphone socket into the CD 6003?