Master Clock questions - cable length etc

I am about a year in with the Teac NT-505 streamer that I took a chance on and really liked and seeing as it's not making me itch for a different piece of digital gear which almost always happens I decided to grab the matching CG-10M master clock.  The main question I have is how important is it to have a 50 ohm cable and secondly am I better off stacking the components and having the shortest possible cable length between DAC and Clock or am I alright using the usual 1-2 meter length that is recommended for a digital cable?

I have started out with the Black Cat Silverstar 75 just to get everything running but apparently 50 ohm is correct, 50 ohm BNC cables seem to be fairly common for broadcast use so if that's the best thing to get so be it.

First impression upon hooking the clock up was that it livens up the sound and puts a bit more flesh on the bone which makes all of the various instruments sound more tangible in the room.  I gave the NT-505 great marks from the get go for having excellent/realistic tone and the clock seems to bring that quality out just a bit more.  

I'm not sure that you would say that the clock represents great value as it's almost as much as the streamer cost wise but it definitely makes a difference and the 2 together definitely make for a very pleasing digital presentation.  
Your description of the effect is spot on. I use an Antelope Audiophile 10m clock with a Zodiac Platinum. I run a 1.5m Shunyata Sigma BNC with great result. The cable quality rather than the length matters greatly and the upgrade compared to the cable supplied with the clock was significant. Obviously the cable is silly money, I also run a Nordost Brahma power cable and Acoustic Revive REM-8 on the clock, increasing the steep cost of the clock by more than 50%. It‘s well worth it.
I tried both a 50 ohm and a 75 ohm cable with my CG-10M. I can't really detect any difference. Having said that, I couldn't really tell much if any difference adding the CG-10M. To be blunt, I think the NT-505 is excellent, the Master Clock however I think is a waste of money. I used fairly short cables and have them stacked for whatever that's worth.
Interesting - placebo effect doesn't usually play into the equation with me I either get closer to the music or I don't and that's all there is to it.  I got a great deal on the clock could likely sell it at a profit but it's staying put for sure.

I'm running the Teac into an LFD NCSE and Harbeth 40.2's, I would consider the system to be forgiving but resolving as well.

As always YMMV as mentioned I don't feel that the clock necessarily represents good value but I am appreciating the effect it has.

I have them stacked right now and will likely try a very short 50 ohm BNC cable just to see if there is any improment to be had.
Your speakers are more resolving than mine and perhaps your hearing is better than mine, but if there's any difference at all it's minimal.

The purpose of a Master Clock is to control multiple devices and sync them together, thus all the inputs on the back of the Master Clock. I'd suggest doing some reading about master clocks before spending money on one.

I bought mine based on claims of sonic improvements. I haven't heard any that were noticeable.
All modern DACs have an input stage that automatically reclocks incoming data. An external reclocker is not necessary! A waste of money! 
Regarding cables - all you need is a true 75 ohm cable 1.5 meter long from transport/streamer to DAC. The make doesn't matter as long as it is 75 ohms and 1.5 meter. Canare is good!
A shorter cable like the 50 ohm you mentioned is not good because of reflections from end-to-end. Stick to 1.5 meter and 75 ohm! Any make will do!
Don't waste your money like antigrunge2 did with expensive cables and a power cord, plus a costly reclocker! These have zero effect upon SQ!
Expectation bias when a new toy is added to the system almost always accounts for so-called improvements in perceived SQ!

wanna come by and listen some or rather keep pontificating? Just because you can’t hear it don’t mean it ain’t there...
And btw, you don’t seem to know the difference between a reclocker and a masterclock...
This is what I had read regarding Mutec clocks apparently it's a different deal versus 75 ohm coax with respect to reflections and jitter because it's working with a square wave not a round wave?

  • Mutec suggests the shorter the BNC cable, the better. So 0.5m would be ideal. A longer clock cable will supposedly introduce more noise. 
    • As opposed to a clock cable, a SPDIF cable is the opposite. Too short of a cable and you’ll get reflections. A 1.25m minimum is recommended for SPDIF.
I'll play around and see what happens there are lots of 50 ohm BNC cables available at various lengths can't hurt to try.  I have found that having a properly designed and specd 75ohm cable like the Black Cat makes a difference for transport to DAC so it stands to reason that having the correct length and cable impedance may be of some importance here.

Thanks guys!
Signal in the cable reflects on impedance boundaries, so matching characteristic impedance of the cable to output/input impedance of your gear is important and the cheaper cable might be a better match in your system than expensive one.  If your master clock requires 50ohm don't even try 75ohm - it doesn't make sense.
Reflections in the cable happen when cable becomes transmission line.  Rule of thumb says that it happens when signal travels longer than 1/8 of transition time.  With typical 25ns transitions it would be (assuming 5ns/m) around 0.6m, but I wouldn't risk more than 1 foot, because length of connections inside of the gear (on both sides) counts.  Most likely you need longer cable and when you don't have perfect impedance match reflections will happen.  The key is for the first reflection (initiated by the beginning of the level change (knee)), to come back after threshold point.  We don't want reflection to modify (to add to) transition.  Assuming threshold point in the middle it has to come later than typical 25ns divided by 2 = 12.5ns.  So signal has to travel both ways longer than 12.5ns equal to 1.25m.  For different transition times it will be different.  Your gear might swing in 30ns and min cable length will be 1.5m.  Transition time is difficult  to measure (without affecting it), while speed of electricity in the cable is dielectric dependent.  Because of that it comes to trial and error.
Transitions are square in S/Pdif and your master clock.  I would expect faster transition times with better transports or perhaps your master clock.  Faster transitions reduce noise induced jitter (weakness of Toslink).  As for all inputs reclocking S/Pdif signal it is not like that.  Most of them have PLL (Phase Lock Loop) that adjust internal D/A conversion clock to average S/Pdif signal rate.  Since time constant is involved (averaging) PLLs are not perfect and can even produce small frequency oscillations of D/A clock.  Reclocker, like one in my Benchmark, uses asynchronous rate conversion, to produce D/A conversion clock, that doesn't even have to be a multiple of S/Pdif (as it is with PLL).   My older reclocking DAC Benchmark DAC1 had D/A conversion at fixed  110kHz independent of incoming S/Pdif signal.  Reclocking process inside of Benchmark DACs reduces D/A conversion time jitter.  Absence of jitter (that converts to noise in frequency domain) makes signal surprisingly clean.