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Phasure HDMI^2 I2S cable experiences?


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Hi David,

 

We can wait a little longer, but I think I know in advance that not many people (if at all) will respond. It's a bit of a chicken-egg thing at this moment. I mean, when this cable emerged, I asked people in advance whether they like to share their experiences with the HDMI^2 (ET^2 the same), but somehow these people are in a group that does not like to post at all, anywhere (they plainly tell me so, honestly). Maybe this is no surprise, knowing that most of these people are from mainland China, who don't speak English much.

All together this cable is going slow (maybe 15 sold so far) which is statistically too few for the "maybe one out of 25 shares his findings" anyway. With the Lush^2 this would even be a too low estimate.

 

What I do hear back of most is an immediate "wow !" (and if not, let them speak up - haha). But this is what it stays at; no further comments on config experiments and with that no experience by me. Additionally I myself don't use the HDMI^2 - I just don't have an application for it.

Btw, the "wow" is to be expected if we look at how the cable is made, which at least is x times better than the standard cables and even how "audiophile" cables are made (I don't see any real "thinking" behind them, contrary to what I write about it myself in the webshop (not disclosing everything of course)). This obviously assumes that you are able to hear differences with HDMI cables in the first place, and if so I almost dare to guarantee that this will sound better right out of the (config) box. And then you can still start tweaking the sound with the configs, which really works out the same as with the Lush^2. That guarantee is by 100% - you will see (if you dare to take the plunge).

 

What may come from this thread is at least a center to share experiences. This wasn't there because I felt reluctant to create one (as the one with commercial interest). So thank you for that.

Btw, what I could do is ask those who bought the HDMI^2 to share in this thread, after all. But to be honest I am not so much the kind of person who abuses email addresses which had to be shared for other reasons. So I really hope this thread comes alive a little, automatically.

 

Thanks and best regards,

Peter

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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41 minutes ago, motberg said:

 

Has any pattern emerged yet concerning the  HDMI^2 cable length vs. performance (when used for i2s transfer) ?

 

Hi Motberg,

 

Nah ... but this is virtually impossible, unless people start to buy two of a different length and compare. And otherwise how could I know myself from customers ...

 

All I know is that i2s it not made for any length of substance BUT it is all about the quality (in various attributes) of the cable as a whole just the same. And this is what I put all the attention too; create a cable for i2s usage that requires the least of "drive", because that is out of our control (this is under the control of your "interface manufacturer" who probably joined in with a hype.

 

I try to think relative ...

IIRC two or three out there are 1m of length. At least they work, and at least they sound for the way better than whatever one had (which I don't know). In some heydays I used i2s at (IIRC) 80cm myself and it replaced an S/PDIF connection. The i2s, despite its length, sounded infinitely better. Still it was way too long and (theoretically) incurred for a lot of jitter. This became clear very well when I assembled the interface of concern right next to the DAC and the piece of i2s became 10 or so cm and the sound was again way better (this is something like 15 years ago).

Relative to that and the poor UTP cable I used for it, and with that explicitly in mind, I tried to improve on that with the HDMI^2 cable. Thicker gauge, lower capacitance, way better shielding, super decent connections and connectors plus a standard implied which for HDMI itself not even exists.

That there's the ^2 shielding is a bonus, but do not forget that the 3 additional shields because of the ^2 application also do a few things to the signal integrity (which unlike e.g. USB is super crucial in this case (as in: 100% crucial).

 

In my opinion, but this is theoretical, a one meter i2s cable of the caliber of the HDMI^2 should be about as OK as the short lengths (like 10cm) i2s is meant for. And oh, please notice that since I design DACs with the lowest net jitter at the outputs, I also know a few things about how to set up the i2s connections which in our case is 32/768 for 10 years by now.  So with that all in mind I'd say that the 1m HDIM^2 will be very OK. But don't overdo it (we can make the cable 10m long if you want, but it won't work well o.O).

 

If things work out problematic, I would look at the damping resistors. For this, there's no general recipe and it is not said that a present e.g. 27 Ohm which might be (should be !) present in your interface works out the best for the larger lengths. So people always talk about length for digital cables, know that too short is not the best most often (like for S/PDIF) but this is all related to reflections which these "damping" resistors are for (which relates to the driving current when things are on the limits).

 

You want two of a different length ? haha

But seriously, we could send you two of a different length and you send one back. And then we know it, for one situation ... (not very efficient but I don't care).

 

Regards,

Peter

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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  • 4 years later...

Hi there Sven,

 

Somehow people don't report on the HDMI^2 (ET^2 / ET^3 the same). Maybe this is because the application for these cables (i2s) is too specific plus it is not a "protocol" application (USB is and there all works out very different and more predictable). It is actually just analogue (never mind it is about 1's and 0's).

 

The only difference that can emerge here, is about jitter (i2s carries the clock signal).
Notice that jitter is audibly foremost discovered by means of the bass. Whether also "hall" (room) I wonder, so this could be a means to determine what it really is about. Notice, however, that lower jitter expresses as more firm bass (more of one frequency when one frequency was intended), which comes to you as LESS lower bass (the more the bass is fumbled, the lower it comes across, and you can feel this on the woofers (more frequencies running through each other)). The "room" as you express it, feels the same to me (fumbling), but I would be on a dangerous path to claim so (especially because you like it better :-)). 
N.b.: From the Lush^ you may recognize how the energy spectrum can vary from wide and flat to deep and holistic. And this by varying the configuration. ... For the i2s application I would not approach it like that - it will work differently.

 

When all the shields are connected, you actually will create a more fuzzy signal path. It could be better shielding, but the path would also be "longer" so to speak. Or even better : there will be several paths for the ground, never mind it is not ground - it influences the signal under it (the data and clock wires). So what I would do : disconnect all small connectors on both ends. Now the shields at least do not influence each other. The shielding may be less, but it depends what actually bothers (we both don't know).

*If* it happens that now the sound becomes even more "warm", it would be my idea that now you created (implied) too much jitter. And, if I am right then less jitter is always "better" as such, which does not tell what you like better.

 

I can blather much more, but it would be best if you can find a difference to begin with. If you do, you may tell what you perceive, and if you don't like what you hear now, connect all he wires on the sending (A) side, and have the B side all disconnected. These variations should bring the largest differences because electrically they "do" the most (for differences).

 

I don't use external i2s myself, so I can't judge. All I can do (could do) is design the very best cable for its properties (like gauge and shield types + isolation means and its properties).

 

Best regards,

Peter

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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Hi Sven,

 

Thank you very much for this detailed report. This is already great because - as told - nobody ever report about these cables and then there is nothing to work out or improve either (and I remain blind).

 

Please be careful not to get fed up with all the configuration possibilities; it is too easy to start randomly change and get mad.
Best would be to find a change in sound by a rough change (like disconnecting all on one side) and then envision what you actually hear. I mean, what the physics behind what you perceive for change could be. In order to be able to do this, look at the schematic of the configuration you implied (you have a few examples only, but they should be sufficient to work out the one you just dialed in). With this, try to see through that you are influencing this :

 

image.png.c3e4e73e810112103856b309678c2a95.png

 

- regarding this picture it is the timing jitter and the amplitude noise.

The more thin those lines are, the less jitter will be in order, the better the sound should be (whatever "better" means, because it can be so that technically better implies that other anomalies in the system become audible - still it is best to have the least jitter).

 

In your case you have the additional dimension of using a wordclock (cable). It is a bit hard for me to see through the dynamics of that because I think it now can be so that you are using two signals which are about equal (the difference would be the difference in cable induced jitter) and they will oscillate (never mind this will be at a minute level deep down somewhere in your DAC). Only if the clock wire of your HDMI is not connected, this would be avoided (if I understand correctly how all is connected in the first place).

Oscillation of this kind is killing, as it will imply a very slow changing jitter spectrum and this would exhibit as not-stable sound.

Please notice that I don't mean that the two clock signals are connected somewhere - it is about the noise both will imply (in-DAC) and that interferes / influences each other.

 

When you are working with this, and you indeed are able to envision what happens inside (no matter whether you are correct on it), you will see that you have 50% chance of changing further in the correct direction. Thus, you change something, then you e.g. perceive more or better (less distorted) highs, and from there you envision how to improve this, based on your thoughts. Then you apply a next change in that direction of which you think it is correct and or it is correct indeed, or it works out the other way around. But, now you know where the direction is to be and can proceed from there (like making the shield LONGER because that is what you do when you'd sequentially connect the shields when nothing is connected in parallel).

 

Dizzy ?

For your Lush^2 or ^3 it works the same, but far more complicated; there too jitter is in order, but not at a direct signal level. This is because USB is based on a protocol (with packets and (varying) packet sizes and such) and you can't say that less jitter will sound better. But it will be different anyway.

 

In your situation the fun would be that you change things on your HDMI connection while the clock signal is not even used in there, while you still perceive changes. This would be similar to my own situation of having an ET^3 as Ethernet cable between a PC that connects over RDC to the (headless) audio PC, where no audio at all flows over that cable (it is only for screen and keyboard control) and that still the sound changes by this cable and its configurations. This is how the "minute" changes (say unmeasurable) still influence via diverse invisible backdoors, in the end always hammering on your precious clock signal.

 

Peter

Lush^3-e      Lush^2      Blaxius^2.5      Ethernet^3     HDMI^2     XLR^2

XXHighEnd (developer)

Phasure NOS1 24/768 Async USB DAC (manufacturer)

Phasure Mach III Audio PC with Linear PSU (manufacturer)

Orelino & Orelo MKII Speakers (designer/supplier)

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