Digital clock - any recommendations?

Any excellent DAC will not benefit from an external clock.

Did you not read the OP? Presumably Esoteric make good DACs with good clocks? dCS also have an adequate reputation yet my Vivaldi stack improved significantly with the addition of the Mutec 10MHz clock.

Besides the performance of the clock having a separate and dedicated power supply and greater isolation from vibration can all help - in my experience in addition to care in choice of the BNC one also should pay attention to footers, power cord and grounding

@mzkmxcv you are also aware that the Esoteric and DCS systems we are discussing are all multi box systems with seperate transports, upsamplers, DACs and so on. Hence the focus on ensuring a consistent master clock between them?

I have no opinion on the effect this would have on a one box system but in the case of multi box systems the benefit of both consistent word clocking at sample rates (ie multiples of 44.1 or 48) and a superior master clock (ie 10 MHz) is obviously audible, st least in my system (DCS Vivaldi based)

Dear @mzkmxcv riddle me this then. Why are the suppliers of external clocks primarily suppliers to recording studios? Presumably the studios can afford the clock impervious DACs of which you speak so highly yet they somehow seem to think it worth investing in master clocks?

My favorite clock and the one I’m looking forward to adding to my system is of course the Abendrot https://abendrot-audio.com

Let’s stick with what the OP asks shall we

He wants to use his Marantz SACD player hence an external DAC is a non starter (as there’s no facility to export DSD).

Marantz provide for a 75ohm BNC master world clock input but provide no data on the stability of the internal clock.

It therefore follows that adding an external clock could improve the sound if any of the following apply
1. The external clock is itself more stable than the one in the Marantz
2. The electrical environment in a stand alone clock is more stable than that in the all in one Marantz (btw this is dCS’ argument for a stand alone clock rather than slaving to the one in the Transport)

As even modestly priced clocks as suggested to the OP probably satisfy both 1 and 2 I’d suggest they give it a try,

This review gives a good description of what to listen for when adding a master clock to a one box system
http://highfidelity.pl/@main-815&lang=en

Y@tzh21y I’m sure you know this but be sure you get a clock that offers 44.1kHz multiple outputs not just 10MHz. The Mutec Ref10 I use or the Abendrot Stute I linked to are 10MHz only and to be used as a Master reference for a playback frequency clock such as the dCS models.

Any of the Esoteric models will work fine or the dCS Rossini or Puccini u clock or the Mutec MC-3, of course any of these can then also have a 10 MHz reference added ... it can get pretty spendy 😉

@mzkmxcv. If you have read the manual for the SA11 S2 you’d know it has an external word clock input ...

As to the value of DSD I suggest you spend some time with sources like this, and really try to listen to a true high end digital rig one day without prejudice. In my system where I listen to all Red Book upsampled to DSDx2 I find that DSD gives a more continuous performance retaining more of the gestalt of performer in room. You’re welcome round my place if you’re ever in the PDX area and want to hear what I mean, changing the sample method and filters is easy and all the adjustments are clearly audible.

What may them blow your mind is to discover that the more esoteric, and costly, the setup the more it responds to detailed tweaks. Yes footers, power cords, damping stones and even anti vibration stickers all matter and are highly audible in a $200k digital setup ... kind of annoying, no 😉

Length of BNC connection vs accuracy of original clock and problems with electrical environment herein -- that's what we call a trade-off, and that's why selection of the BNC cable matters. Of course in your black and white 44.1/16 = perfect world you don't care

As to musicians and producers -- well I guess on an audiophile discussion board we perhaps care more about those who do know what DSD is -- did you look up the Cookie Marenco link I posted? Those are the sorts of people we should be taking advice from ...

Once again our friend  @mzkmxcv gets it all wrong. While clocks can help synch multiple devices a stand alone clock can also benefit a single device - were you not paying attention when I said to look at the dCS Rossini or Puccini setups or the review of the Vivaldi one? All of these single box systems that benefit from add on clocks

And your opinions on the perfection that is Red Book PCM are at odds with the vast majority of musicians, producers and audiophiles - again please take one of us up on listening to a real high end digital setup one day.

Might I suggest you buzz off and leave the op alone if you have nothing new to add?

Hmmm, one test with a 20 year old upsampler (not a dedicated clock) proves what? Odd how dCS themselves still promote external clocking in all their ranges, I guess all of their DACs are “garbage”, mine certainly is 🤪

External clocking is tricky stuff. For instance clocking at multiples of the base rate (eg 88.2, 166.4) often sounds worse even when you’re sampling at these rates. Per John Quick the issue seems to be transmitting these higher rate signals via BNC. Best to stick with 44.1/48 even if your clock supports higher rates imho at least

Anyway, @tzh21y have you had a chance to try one of the suggestions yet? Would be great to hear back what you found when you have a chance