By the way, I should have said... GOOD POWER VS Clarity
Yeah it depends on what your looking to spend.. Many times the Dac will be a bigger step if your dropping a grand, and your DVD player is not the greatest source.. Try a DAC with a return policy, its easier to ship and deal with, see what happens, then if its not all its cracked up to be and you feel the cambridge player is good in comparison, then go for an amp as the NAD could definatly be improved too..
By the way I have tested Dac's vs. the Player by hooking the DAC up to your Auxilary input on the preamp or receiver/intergrated, and then leave the CD player on the CD input, you can then Switch back and Forth on the Fly with the remote and hear the immediate difference in sound.. This will lead you in the direction you seek, and no regrets if one strikes you better..
The Dac would probably need at least a week of burn in 24-7 as a warning before it really opens up, so I would not take an immediate comparison out of the box... and of course this test would be best using 2 sets of equal interconnects, one set for the player, and one set for the DAC. And of course you will need a digital cable for transport to dac connection.
No other good way to know what your better option is without trying it in your system honestly. Like I said end result is you feel the DAC made large direct A-B comparison improvements or not.. Then ship it back for a little loss in shipping and go after an amp.
Cool, now we've got something to work with. I think your speakers are fine, PMC is pretty well known for their accurate montioring speakers. I can imagine they have a lot of untapped potential.
How much do you have to spend on a component(integrated or cd) upgrade?
It might be worth trying out some different cables, my brother was using a full set of their higher-end models with his Audio Research 100.2 amp, AR LS-15 preamp, and Vandersteen 3A Sig speakers. I always felt that combo seemed shut in, restricted, or muted. It took me a couple of years to get him to try other cables, but hen he did, things opened up considerably.
Fatwyre.com/The Cable Company has a cable lending library of hundreds of used high-end pieces. For something like %5 of the cable's total worth, you can rent several different makes or models for two weeks. When I was looking for a new digital cable for my dac, I rented 4 cables ranging from $50-500 to compare. I think it cost me something in the area of $35 total. If you end up buying a piece from them, your rental fee is applied towards the >1/2 off purchase price. They also prived expert advice on potential "bests" for your system and price range.