best CDP for QuadQC24+Quad909+DynoA72

Here is my vote for the Naim and Primare. The Saturn can be very good but I find more system dependent. I have not heard that model MF or the T&A. Other MF CDPs (A3.5 and A5) sound pretty good, but nothing remarkable. Nothing else sounds like a Naim.

is the RBCD SQ of marantz sa-15 close to naim cd5x? is SACD SQ of marantz definitely better than RB SQ of naim?

The redbook performance of the Naim and the Marantz are different flavors. The Marantz is smooth and refined with decent retrieval of details, I would call it "pretty" sounding. The Naim has good detail but adds a dollop of boogie on top of the refinement, I would call it "musical" (the CD5 XS is a significant upgrade from the CD5x, more so than the change from SA-15S1 to SA-15S2). For redbook only, I would choose the Naim. I think I would also prefer the Primare which is somewhere between the two in terms of choosing a side of pancakes with syrup or bacon, to use a breakfast metaphor).

For SACD playback - I mean, is there really a choice? The Marantz playing a well recorded SACD will smoke all the other redbook players if the rest of your system is up to revealing the detail, weight and space available in that format. If SACD is important to you - then I would buy the Marantz. You are probably familiar with all the backstory of that format - if you already have a significant collection of SACDs then this becomes a legitimate choice. If you are thinking of getting into the SACD play at what looks like the last act - not sure it pencils out.

thanks knownothing for your answers. my dilemma is the following: i heard marantz with quad electronics, and they were pretty good, and excellent on classical music, but on jazz or rock it was a little bit laid back, so all the excellent presence at classical music are gone when the music gets 'rolling' with some rock or hard beat (jazz with classical instrument is also good). so on classical music it really PLAYS the music, has soul, presence. but i listen to marcus miller, stanley clark and funk jazz as well. i also heard exposure cdp+amp, but -although they were great- they were a bit 'analitical' for me, but very detailed. so my point here is that i don't want analitical sound but i like details, and i like to feel the soul of the music and presence...

Naim CD5 XS.

i managed to have a short listening session of marantz sa15s1, and i also compared rbcd to sacd on this cdp: i was astonished how much better the sq of sacd ovef rbcd! although the german audio mag rates this marantz in reference league on rbcd, i wonder how comes that there are reviewers (e.g. stereophile) writing that the best rb cdp equaling or bettering the sq of sa cdp? i simply cannot imagine... in my experience the difference was huge and apperent! without question! moreover the sound of sacd is much-much-much more relaxed, naturer, better resolution and dynamics (dynamics are way ahead of rbcd), and switching back to rbcd, the rbcd is ever harsh and annoying, even on this reference cdp. any experince in this matter? my conclusion is that sacd is a must-have even if there're not many sacds on the market... for classical music listeners there's simply no other way except of course vinyl... i'm quite certain of getting a marantzsa15s2 and a rega p3 to my system...