Disadvantages of OP amps in output stage of CD?

Al, Thanks for the thorough explanation of the "op-amp" functionality. Yes, I did spell "discrete" incorrectly in this particular context.....I possibly did not mentally transition quick enough from an on-line dating service to Audiogon.

Nevertheless, I think you covered all the options. However, a $1000-1500 DAC will not or can not be done. Equally, even if I can get a refund for the modded 550C, and sell the Rega Apollo, a $3000-3500 CD player will not happen either which may be the (starting) range to as you noted.... "accomplish the same thing" as using a two box appproach.

The Ayre CX-7mp2 comes to mind, and/or the current top of the line Sim Audio player. The Rega Isis, even used, is not worth the money. However, I remain undaunted in finding a more than acceptable alternative and the right sound quality.

To Nonoise, Thanks for the link....maybe "out of chaos comes order" Not sure who said this: either Pee Wee Herman, or Frederich Nietzche??

To Elizabeth, I am sure how your comments are either helpful or productive. Almarg, Nonoise and others who have given their time and knowledge on this thread and others I have intiated are not fools participating in the sport of one upsmanship. Op-amp is not a buzzword, but an electronic device which both designers and consumers like and dislike. Neverhteless, it is better to know what it does and its potential downside in the playback chain. This hobby is driven by the science of electronics not magic.

Maybe, Elizabeth , you could tell us about your audio system, and what aspects could be improved. Regretably, I fell victim to BS and hype surrounding the modded player I purchased. In our excitement to find the best sound with in reason, audiophiles can and do make mistakes.

Happily, the player in question is going back to its owner, whether I send it or deliver it in person. I don't want it because it does not do what the hype claims it can do. I will reinstall the Rega Apollo, and continued to look for a better player, or just find a Rega Saturn which supposedly bests its little brother across the board. That was my original plan which I should have stuck by, and avoid losing the shipping costs that I have. Will keep you all posted. Thanks. Jimbo

BW, Unfortunately, you are speaking to a somewhat non-technical person. Though, I greatly appreciate your advice and explantion. This player as noted was modded by Mapleshade Audio, the music and tweek internet company. In all fairness to its sound it does have lighting fast transient response and a low noise floor. BTW, I did make a speaker cable change (downward) before acquiring the Cambridge 550C. When I had the Rega Apollo in system, the differences with the less expensive cable (Audio Art SC-5 standard) were apparent but could be lived with. When I plugged in the 550C,. those differences became much more pronounced. The sound was bleached on the top end and through most of the midrange; this is the exact opposite of what I anticpated. and lacked any musicality.

As it stands now, I have ran 550C to about 100 hours burn-in, and 25 hrs actually play time. It sounds the same The third party seller could offer "only" his regrets that the player did not "work well" in my system, which is not a general audio premise I subscribed to I am not going to put anymore money into trying to get 550C to sound better by adding an even inexpensive DAC like the Peachtree I-DAC or eqivalent If anyone has any additional suggestions, please let me know. Otherwise, I intend to sell the unit cheaply, take a finanicial bath, and move on. Jim