Benefits of adding a 10MHz Master Clock to a digital system

As a long time DCS stack owner (first Paganini, currently Vivaldi V2) I’ve been a convert to the value of dedicated clocking systems. In the context of a DCS setup this means including a dedicated clock unit that provides a combination of 44.1KHz and 48KHz signals to each of the other units in the system (the transport, DAC and up-sampler in the case of a full four box stack).

The DCS clocks are pretty darn expensive boxes and while they (like all DCS gear) benefit greatly from upgrading power cords, 75 ohm interconnects and feet I had never really thought that adding a further reference clock would bring any benefit. However piqued by the following recent review of the Vivaldi One in which the addition of both the Vivaldi clock and a Cybershaft 10MHz reference brought great benefit I wondered if I’d been mistaken and if an external 10MHz reference could add even more to my system.

Some on line research quickly made it clear that the Cybershaft OCXO clock used in the review is unobtanium so the question is who else makes a good clock? Online commentators seemed to think quite highly of the Ref10 from Mutec so that’s what I opted for from an Amazon seller. The Ref10 is a solidly made but very utilitarian box. It provides up to 8 outputs all on BNC, a mix of 6 at 75Ohm and 2 at 50Ohm so will match with whatever you have.

The DCS is 75Ohm so as soon as I had the Ref10 I installed it using a generic 75OHM BNC and the stock power cord. Notwithstanding recommendations to leave it on for 48 hours to stabilize the first impressions were very favorable. With the addition of the reference clock I was hearing further into the recording and also appreciating a surprisingly large increase in rhythmic consistency and bass realism (i.e. bass seemed crisper and less boomy with the elimination of a sense of overhang in the 80-120Hz range that had plagued my system before)

What then amazed me was how much further improvement upgrading the power cord (to Marigo Iridium V2) and BNC (to Marigo Apparition Extreme 75Ohm) brought - even more air and clarity. The final icing was optimizing the support under the Ref 10 with Marigo RHZ feet on a Marigo platform. I've now had the Ref10 in my system for several weeks and frankly it's probably the first time I'm really beginning to believe that digital can give my analog setup a real challenge -- with how I have it now I feel as if I'm hearing two increasingly similar takes on the same absolute -- digital converging on all the best in terms of space and realism I've found in analog, while the latter (with the recent addition of Ron Heydrich's latest power cord on my turntable PSU) getting the speed stability and rhythmic integrity that digital can do so well.

Overall in the context of a megabuck DCS setup it was surprising how much benefit a relatively modestly priced ($3595) professional grade add on brought. That I then added nearly $9K of tweaks to it probably speaks more to my obsessive nature (and budget I guess) but overall consider me a full convert to the benefits of 10MHz master clocking in any attempt to scale the heights of digital reproduction.
Just noticed the following add ons - frankly if you cannot hear the effect of a clock change in a Vivaldi level system you need a new (more resolving) system. I can hear the effect of changing the footers under my master clock, and the ground wire connecting the master clock to its Taiko ground block, and the footers under that .. I recently had the Mutec upgraded to SE status and also some other work done on it to improve the power supplies -- all very obvious changes

Nevertheless all of these changes pale next to optimising the room (but that's a whole different story!)
Thanks for chiming in OP.  I would challenge your precept that $4K is a "modest" investment for an "upgrade" to a source, let alone, another $9K in "tweaks" for most people on this forum.  If you've got the green and it's worth it to you, that's great.  At that level, I would hope that the improvements are noticeable.

To be fair, I went back and did some listening with my clock on and off recently as a result of this thread and I was able to perceive some minor differences in sound quality, but nothing that I could specifically put my finger on or that made it worth the not so modest amount (to me) that I spent on the clock.

Now last night I added a new phono stage to my system that cost a little over $3K, and... yowza!  Money well spent!  There were significant improvements in separation and detail of instruments and voices, soundstage, pace and rythym, and the overall body of the music.  These were things that I could easily perceive and describe.
Context is everything, this is a discussion of changes on a $100k digital source, if you are playing at this level then $10k is pocket change and your system should resolve the improvements. I have no opinion whatsoever on whether the return on investment is worth it in more real world systems, frankly I’d agree with you that it’s not, but the odd thing in my experience is that the more expensive the system the more it benefits from tweaks, a sort of “increasing returns” so to speak. 
I am using a Mutec Ref10 to clock a SOtM switch and Uptone EtherRegen.  Unquestionable benefits.  Not sure if I have a real world system.  It did reveal to me a harshness I was able to track down to SFP modules between the switches, got that fixed and now I'm in heaven.

The upgrade bug has been in hibernation since....well there is the CAD grounding box I am thinking of demo'ing 
“Maybe you should tell Esoteric/DCS/MSB that they dont know what they are doing.“

I never said that. Of course they have the expertise and the resources to do it right. Possibly  to sell you more components. When you’re  dealing with timing, you want to keep things close to the board. Just think about all that’s involved in separate components having to communicate.. why not keep things more simple?  Having separate components is nice and allows for easier upgrades and it’s fine if you like spending big money, it’s just not necessary.