Do you think I should use the internal DAC of the Arcam or use a good CDP for music listening? I have the Oppo DVD player (see my other post), don't know should I use it with the Arcam via digital output or buy the Naim CD5i CDP that I am thinking buying it. Thanks.
It all depends. I haven't heard the Oppo in any way, nor have I heard the Arcam's DACs.
Have you tried the Oppo using the Arcam's digital input? It should be the cheapest route. If you don't have a digital cable laying around the house, pick one up at Best Buy or the like. You should have 30 days to return it if the need arises.
Have you heard the CD5i with your gear, in your room, with your music? Will your dealer let you take home a demo player to audition?
I'm pretty sure the CD5i will sound better. How much better and if its worth it is subjective and dependent on your financial means.