A Confused streaming system - Mutec / SOtM Ultra

[Confused]

The NB will of course work fine without any external clocks, but if you want to use the word clock inputs, it is best to have two feeds using 44.1kHz and 48kHz family rates respectively, in which case I think you would need two MC3+USB's.

Thx for the response. Why would it be best to use one feed per family rate? (pls excuse the Ref10 newbie question)  

Because that is how word clocks are designed to work.  The idea behind word clocks is that they synchronise the clocks through a system.  In addition, a high quality master clock can reduce jitter in addition to providing full synchronisation.  So in a full dCS rig, the master clock might be connected to both the streamer and the DAC.  If you are running 44.1kHz material, then the 44.1kHz clock feed will be used, and exactly the same clock is sychronised between the DAC and the source.  If you switch to 48kHz material (or 96kHz / 192kHz), the 44.1 clock feed will not work, you need one in the 48kHz family.  For this reason, the Network Bridge has two clock input connections, one for each clock rate family.  In practical terms, if you feed the Network Bridge a 48kHz word clock feed, and then play 44.1kHz material, the Network Bridge would ignore the 48kHz feed from the Mutec kit, it cannot use it, and would default to it's internal clock.  This is why upsampling in Roon can mitigate this issue, you could send the Network Bridge a 192kHz feed irrespective of the native rate of the source material, so only the 48kHz family word clock feed would be needed. 

This is a different concept to the REF10 reference clock idea.  The REF10 (and similar products from other manufacturers) provide a 10MHz reference clock signal.  This should improve the clock accuracy of the device to which you feed it, and devices like the SOtM Ultra range and the Mutec MC3+USB can accept the 10MHz signal, and use it for whatever sample rate music you might want to listen to.  It is in this way that the MC3+USB can used with the REF10 to produce a very accurate word clock feed, this can be sent to the Network Bridge, the MC3+USB can accept the 10MHz feed and has a clock board that can generate the 44.1 or 48kHz frequencies.  The sCLK-EX board in the SOtMultra devices works in a similar way, it can accept a 10MHz reference feed, and can distribute an accurate clock feed at a variety of frequencies, to suit a streamer, a network switch, or a whole range of other things.

When used with a Devialet, you cannot synchronise the clock in the DAC as you would in a dCS rig, but if the word clock is accurate enough, it should in theory reduce the jitter in the Network Bridge and improve the performance.  I say in theory, the end result would depend on losses in the clock cables and how good the built-in clock is, the better it is, the harder it will be to improve upon.  The built in clock has the advantage of being directly connected to whatever is using the clock, with no cable losses.  10MHz clock cables can suffer losses and interference, which goes some way to explain why the REF10's performance seems to be dependant on the quality of cables, far more than you would expect compared to S/PID or USB cables.

Page 25 of the Network Bridge manual provides some clarity with respect to the word clock inputs:

https://dcsltd.a.cdnify.io/wp-content/up...-v1_0x.pdf

Or you could just use AIR, not worry about this nonsense and enjoy a tune or two.