Is a preamp necessary?

My recommendation is, why don't you just try it? Hook up directly with the DAP driving the B & K and see if it sounds better than with your NAD in the circuit? (I know folks that are driving amps directly with the DAP, although I believe Proceed recommends using a pre-amp.) If it sounds better without the NAD, live with it for a while, and hold off on buying that new pre-amp. All that having been said, I am one of those folks that Tom nice referred to that likes an active pre-amp in the signal path, a tube pre-amp at that.

My opinion, for what it's worth.

An Accuphase DP-65 or DP-75 runs very well "straight in". I sold a CAT SL-1 III with factory-simplified signal path because it was SO much less transparent than a top quality DIY passive preamp. But the my Accuphase DP-75 "straight in" is OBVIOUSLY better even than the best possive passive. I'll never own an active preamp again, but tastes differ. Some people are going to LIKE what an active preamp adds to the recorded sound. And who could object to that?

OK I HAVE HAD THE SAME PROBLEM IN THE PAST AND HERE IS YOUR ANSWER. I use a mark levinson 335 and a theta miles cd player I was running direct for about one year it sounded awesome but then I added a levinson 38 preamp and I gained a lot of headroom better bass, better focas , better imaging. lets just say everything had gotton better on a whole. but it did sound awesome with out the preamp in the loop. now this is very important if you are going to run direct there are only a couple of cd players that will do it and do it well. 1 mark levinson 39 2 theta miles 3 wadia 830 850 or the 860. A dealer will tell you anything he wants but I have nothing to gain here. The best one to use would be the mark levinson 39 because it was made for running direct it has a preamp inside of it .on the other hand it isnt upgradeable to the new formats at this time. the theta miles would be my second choice out of the 3 because it also has an anologe volume control as does the 39. Having an anologe volume control is much better than digital because you dont lose bits of information when you turn down the volume it just gets quiter. the wadia gear is awesome also But I found it to get a little brite when you start to get on it a little. also the b&k can sound a little brite at times so you want to add a source that has a warm but natural tone to it. and the 39 & the theta miles are more natural sounding than the wadia. so yes you can bypass the preamp. But do it right. Running direct has been a debate for years. some yes the less the components the faster the signal flows the better the sound. some say that the power supplys in a cd player are much smaller of that in a preamp so you get better voltage swings with having a preamp if you buy the right playerit will sound awesome no matter how you run it. good luck hope this helps. email with any questions you may have. my equipment is
Mark Levinson 335
Mark Levinson 38
Theta Miles cd plyaer
Martin Logan Aerius i
Harmonic Technologies cables