So sad ... when I play HiRes files using the Blaxius^2 BNC cable I just get crackling noise and the display of the DAVE starts to flicker. How is this possible when the M Scaler is upsampling to 705 kHz anyway? I have no problem with 44 kHz files.
Hi yellowblue. If you and people allow me, we'll try to sort this issue in this thread. I mean, we could do it by email, but since you won't be the only one with the Blaxius^2 and we all like it to work, I think it is best to deal with this publically.
Many audiophile cables are not correct RF grade cables with 75 ohm. This is the reason I persuaded Chord to giveaway RF cables, to ensure a technically correct connection was made; it is also the cable that M scalers and DACs are tested against.
768 kHz using SPDIF is technically extremely challenging, this is why you do not see any other company worldwide running at this rate.
@Rob Watts, I understand and agree and have the experience you're talking about etc. But FYI, the cable is officially rated at 75 Ohm end to end, and that at 6GHz at a length of 130m, -3dB.
Maybe the 768KHz is too challenging for SPDIF ? Maybe it now too much depends on the length of the cable and the reflections occurring at this specific length and rate, or *lacking* at this length and rate (just saying) ?
Anyway, we'll work this out. So allow us a few back and forth questions, with later on the day hopefully a second customer of M Scaler and Blaxius^2 to contribute.
@yellowblue, would it be so that at 384 output all works again ? Thus 8x instead of 16x upsampling.
Also, if you have a Hires which is 44.1 based (like 88.2, 176.4), these normally work upsampled to 705.6 ? I'm asking, because there could be a relation to the input as well (different RF fields, whatever).
On the picture you showed (CA) ... do I see it correctly that you put the B side in the M Scaler ? If so and assumed the M Scaler outputs through the BNC cables (sorry for the daft suggestion - I just don't know), you connected the target end of the cables to the source. I am not saying that the issue will be solved if you turn around the cables (connect the A = source side to the M Scaler for output), but formally that was the idea about the configuration the Blaxius^2 was supplied to you.
It would be correct that I did not test these cables with the M Scaler as I do now own one. And as Rob suggested, not many other devices around to test it with. Point also is : this cable is configurable for a reason, although the reason is "Sound Quality" and not "connect". It should do the latter by all means, obviously. However, don't ask me how eye diagrams look when connected to the M Scaler. Also don't ask me which configuration does what to it (but it will influence by guarantee). And Rob, FYI : what's configurable is the shields (3 of them). So obviously this matters, especially in an RF environment which we can regard this is.
Additionally interesting is what I read in this thread about the galvanic isolation. If anything is detrimental to signal integrity it is that, and I don't mean this in the positive sense. BUT, I surely don't mean to say that it is not OK to have it. Only that it makes it more difficult. And for background maybe : I was the first to come up with the Intona and I was also the first who implemented Galvanic Isolation in-DAC (with a stupid chips starting with S born in Australia), so let's say I have some experience (and with a DAC which does 768 since 2011).
To yellowblue again : the most normal configuration would be A:B-W, B:B-W. Might you not like to turn around the (A-B) cables, then this config won't matter because now both sides are the same.
This config now uses the innermost shield only which now also conducts the ground return. It would equal the original Blaxius of which it is known that it works, at least on one M Scaler. But, two additional shields now surround it and with all the hoopla and extra dielectric the impedance could change somewhat. At this moment I have no judgment other than subjective how this 75 Ohm would be influenced by this super small range the ~480Mbit (480 MHz) which is implied here (on the bandwidth of the 6GHz the cable can do). And Rob, maybe you can tell me the real bit rate occurring in this case because for SPDIF I really don't know, plus it seems to me that per cable it is half anyway (you're using two connections to form the total bandwidth, right ?).
If there is a possibility to get me a loaner so I can sort it out with measurement and all, I would instantly do it. But for now let's first try the more common sense things.
Thanks,
Peter
