Gary,
I use a Cary CD-308 connected directly to my amps. I think it sounds great.
I recently borrowed a highly praised $4000 tube pre-amp from a friend for a comparision. With the pre-amp in the circuit, I got slightly better dynamics, but the cost in dollars and rack space did not justify adding a pre-amp to my system.
As long as I have a single source system, it will be CD/DAC directly connected to my amps.
BTW, I have also had great results using a Theta Miles CDp(balanced version), Birdland O'deon Lite DAC, Camelot Uther Mk IV DAC connected directly to amps.
Enjoy,
TIC