Whatjd, I think several people might be responding to the delta between CD and SACD formats and not necessarily to your question. I believe you are asking about an SACD’s playback of Redbook CDs, so I'll throw in my $0.02.
From my listening experience, which is admittedly limited, I would have to agree with LFR that Redbook CD playback is not on par with mid to hi quality CD players. Many a post espousing SACD playback quality has further stated that perhaps a good outboard DAC for Redbook playback is a better option than straight out of the SACD player (Several folks have talked about the output stage quality being questionable on the 777 and SCD-1). I have seen this written more on the SCD-1 and 777 than on the Marantz SA-1 (not even sure if it was written about the SA-1), which I have never auditioned. The outboard option has intrigued me, but the expense of an SACD player and quality outboard DAC has prevented me from going this route, as of yet anyway.
My opinion, for what it’s worth.
From my listening experience, which is admittedly limited, I would have to agree with LFR that Redbook CD playback is not on par with mid to hi quality CD players. Many a post espousing SACD playback quality has further stated that perhaps a good outboard DAC for Redbook playback is a better option than straight out of the SACD player (Several folks have talked about the output stage quality being questionable on the 777 and SCD-1). I have seen this written more on the SCD-1 and 777 than on the Marantz SA-1 (not even sure if it was written about the SA-1), which I have never auditioned. The outboard option has intrigued me, but the expense of an SACD player and quality outboard DAC has prevented me from going this route, as of yet anyway.
My opinion, for what it’s worth.