I2S Cables?

[GoldTone]

I'm new here, looks like a cool place to read and interact with fellow audio lovers.

I was wondering what people are using for I2S cables, now that the HDMI standard is used by a larger number of transports and D/A converters? I know some of them use different pin configurations so that's something to be careful about. Assuming your transport does talk the same language as your converter, it doesn't seem like there are very many options compared to power cables, speaker cables, or other more traditional types.

So what are people around here using?

 

[GSOphile]

I2S is an INTERNAL protocol - not a type of cable - often different from one manufacturer to another, used to communicate within a device. Some have used it for external communications, some of these to get around SACD legal restrictions which apply when one manufacturer's device sends DSD data to another manufacturer's device. A vendor may choose different physical media (e.g., HDMI is one) with different signaling conventions for the cable media chosen. The thing to be cognizant of is that there is no real recognized standard that a manufacturer can design to and be confident that his device will function properly with another manufacturer's unless commitments are made, specifications are agreed upon, testing happens, etc. The most useful discussion I have seen on this topic can be found in the MSB Technologies forum.

 

[ptman]

I use an AudioMica Artoc Ultra Reference RJ45 for the I2S connection between my Bricasti M19 transport and M1 Series II DAC. Sounds great.

 

[GSOphile]

I use an AudioMica Artoc Ultra Reference RJ45 for the I2S connection between my Bricasti M19 transport and M1 Series II DAC. Sounds great.

There shouldn't be a problem connecting pieces from the same manufacturer using their own proprietary I2S protocol. And I note that Bricasti describes their I2S as "proprietary," whereas a review of the M19 in Future Audiophile takes the liberty of describing the same Bricasti's I2S as "the standard data protocol." This is misinformation.

 

[GSOphile]

And welcome, GoldTone! Please forgive me putting my reply to your question before my welcome. I should know better.

 

[crwilli]

There shouldn't be a problem connecting pieces from the same manufacturer using their own proprietary I2S protocol. And I note that Bricasti describes their I2S as "proprietary," whereas a review of the M19 in Future Audiophile takes the liberty of describing the same Bricasti's I2S as "the standard data protocol." This is misinformation.

Bricasti uses an RJ45 cable for their i2S transmission between the M19 and for example, the M21. I do not think they use the HDMI form factor.

Apparently, they can still perform the ‘standard data protocol’ with an RJ45 cable.

 

[crwilli]

I'm new here, looks like a cool place to read and interact with fellow audio lovers.

I was wondering what people are using for I2S cables, now that the HDMI standard is used by a larger number of transports and D/A converters? I know some of them use different pin configurations so that's something to be careful about. Assuming your transport does talk the same language as your converter, it doesn't seem like there are very many options compared to power cables, speaker cables, or other more traditional types.

So what are people around here using?

I use a Tubulus Concentus HDMI cable between my Antipodes K50 and the i2S module in my MSB Premier DAC. Works like a charm!

 

[GSOphile]

Bricasti uses an RJ45 cable for their i2S transmission between the M19 and for example, the M21. I do not think they use the HDMI form factor.

Apparently, they can still perform the ‘standard data protocol’ with an RJ45 cable.

Correct. They do not use HDMI. Yes, they could have used either for a proprietary version of I2S. According to MSB, who supports several non-MSB versions of I2S via HDMI, there is no recognized I2S standard. MSB believes that the HDMI form factor has advantages over RJ45 for providing a supported interface for several selected vendors.

 

[GoldTone]

Thank you for the replies (and the warm welcome).

My most recent upgrade is the Eversolo T10 transport. That replaces my old SOtM SMS-200 which only had USB output. I'll be upgrading my DAC next. Everything I'm considering seems to have I2S over HDMI and should work with my new T10.

I have checked out the Tubulus models as those come highly recommended. I also hear good things about the Wireworld Platinum, Veritas Optimus, and the affordable option from DH Labs. I'll keep reading up and see which ones appeal to me, then try to demo those.

 

[GSOphile]

Thank you for the replies (and the warm welcome).

My most recent upgrade is the Eversolo T10 transport. That replaces my old SOtM SMS-200 which only had USB output. I'll be upgrading my DAC next. Everything I'm considering seems to have I2S over HDMI and should work with my new T10.

Nope. You're missing the point. It's your DAC choice and the flavor of I2S input that the DAC is expecting to see over whatever HDMI cable you select that will matter. If it's not an Eversolo DAC with an I2S input, I don't know what more I can say.

I have no experience/opinion on various premium HDMI cable offerings.

 

[Darrel]

When I added the LAiV uDDC to my Harmony DAC I found an old 1/2 meter HDMI cable out of my box of old home theater HDMI cables. Its only redeeming quality was that it had ferrites on each end. I plugged it in to each unit. It was recognised by both and I've been happy with its performance. I think it was around $20 at the time of purchase.

 

[GoldTone]

Nope. You're missing the point. It's your DAC choice and the flavor of I2S input that the DAC is expecting to see over whatever HDMI cable you select that will matter. If it's not an Eversolo DAC with an I2S input, I don't know what more I can say.

I have no experience/opinion on various premium HDMI cable offerings.

I don't think I am. I'm not trying to be argumentative at all, so please don't take this the wrong way. And I'm aware that there is technically no set standard that totally governs I2S outputs when done via HDMI.

However there are a few common types of pin configuration that have emerged which are used by the majority of brands out there. The most popular I'm aware of is used by PS Audio, Sonore, Holo Audio, Denafrips, Matrix Audio, Audio GD, Mola Mola, and various others. That means a transport by any one of these will work well with a DAC from anyone else on this list.

Eversolo is one of several brands I'm aware of which offer configurable pin definitions for their I2S output. Some do it via hardware (DIP switches for example) but others like Eversolo do it in software, giving you 8 different choices. That should cover the majority of DACs out there which feature I2S HDMI inputs, including everyone on my list above.

So yes, obviously sticking with the same brand for transport and DAC is a great way to take the guesswork out of it. But things have evolved by now to the point where there is a lot more interoperability involved than you are insinuating.

My question really was about cables and what folks here are using or enjoying. User crwilli above is using a Tubulus I2S between his Antipodes transport and MSB DAC, with great results. So I am just looking for more examples like that.

 

[crwilli]

Seems to me a related question is what impact does the HDMI cable have on the i2S signals? I understand that’s a perpetual $64,000 question surrounded by mystery, intrigue and sometimes intense emotions.

My Chat GPT friend provided the following when asked what the most important aspects of an HDMI /i2s cable would be in order of priority. Here are the top four:

1	Correct, stable characteristic impedance	Critical	Minimizes reflections and preserves the shape/timing of the high-speed digital edges.
2	Matched propagation delay / low pair-to-pair skew	Critical	I2S sends clock and data separately. Their relative arrival times matter.
3	Consistent conductor geometry	Very high	Determines impedance, skew, capacitance and inductance. Precision construction matters more than exotic materials.
4	Effective shielding / common-mode noise control	Very high	Limits RF/EMI coupling and can reduce high-frequency noise transferred between components.

It seems construction is more important than the metallurgy of the wire (copper or silver for example).

 

[Mr Peabody]

I haven't looked at HDMI spec in years. When I did, I do know it's more important to have the current high speed and other up to date specs. I used Tributaries HDMI for my HT stuff. I know HDMI was hotly debated back in the day whether it's worth spending more. I bought some $40.00 cables and was having some drop out issues, went to the Tributaries and everything worked fine. Wire World is also a good brand.

I'm not sure where IS2 ranks in digital connections IMO I'd avoid using HDMI. Just trauma from early adoption, LOL

 

[W9TR]

It’s interesting that audio manufacturers are choosing to use a data bus specifically designed for internal device to device and PWB to PWB communications as an external bus. I2S has no error correction.

This immediately raises some challenges that manufacturers have to manage. The I2S bus is not designed to drive cables. So manufacturers have to buffer the I2S buss before presenting it to the outside world. How they do that is critical, as the drivers they use must be matched to the characteristic impedance of the cable. Cat X cables and aHDMI cables are 100 Ohms differential and there are line drivers available for this impedance.

As has been noted there is no standard physical
Implementation. 3 BNC, 3 RCA, 8P8C aka RJ-45, and HDMI are all being used. Welcome to the Wild West. I2S uses three data/clock lines and 8P8C and HDMI have 4 differential pairs, so how the manufacturer assigns those is up on the air. I think there are two common pinouts.

Why use I2S? Because unlike the S/PDIF series data standard it has separate clock and data lines which means you do not have to extract the clock signal at the receiver. This allows for a potential jitter reduction.

So what’s an audiophile to do for I2S?
1. Choose devices from the same manufacturer that have been tested together as a system.
2. Choose HDMI cables that are copper and high speed. Boutique cables are a thing here as well.

If a manufacturer specifies or recommends a cable, I’d definitely use that. There are so many variables in how manufacturers implement this “standard”. As a consumer it’s a crap-shoot.

 

[crwilli]

It’s interesting that audio manufacturers are choosing to use a data bus specifically designed for internal device to device and PWB to PWB communications as an external bus. I2S has no error correction.

This immediately raises some challenges that manufacturers have to manage. The I2S bus is not designed to drive cables. So manufacturers have to buffer the I2S buss before presenting it to the outside world. How they do that is critical, as the drivers they use must be matched to the characteristic impedance of the cable. Cat X cables and aHDMI cables are 100 Ohms differential and there are line drivers available for this impedance.

As has been noted there is no standard physical
Implementation. 3 BNC, 3 RCA, 8P8C aka RJ-45, and HDMI are all being used. Welcome to the Wild West. I2S uses three data/clock lines and 8P8C and HDMI have 4 differential pairs, so how the manufacturer assigns those is up on the air. I think there are two common pinouts.

Why use I2S? Because unlike the S/PDIF series data standard it has separate clock and data lines which means you do not have to extract the clock signal at the receiver. This allows for a potential jitter reduction.

So what’s an audiophile to do for I2S?
1. Choose devices from the same manufacturer that have been tested together as a system.
2. Choose HDMI cables that are copper and high speed. Boutique cables are a thing here as well.

If a manufacturer specifies or recommends a cable, I’d definitely use that. There are so many variables in how manufacturers implement this “standard”. As a consumer it’s a crap-shoot.

In my case, I have a server (Antipodes) tested by my DAC maker (MSB). I would offer that is as good as buying both from the same manufacturer.

As for the cable, it’s not clear to me that high speed is an important criteria. It isn’t from my AI friends perspective. UNLESS precise construction gets you high speed???

I am also sensitive to the importance of RF rejection. Again, something construction can address.

 

[W9TR]

Yep, you are golden with a tested interface.

Higher precision, better impedance control, and higher bandwidth means better consistency of timing between the clocks and data.

High Speed is now the lowest speed HDMI cable you can buy, apart from questionable sellers on Amazon. DSD 512 and 352 kHz 32 bit 2 channel have data rates of approx 11 mbps and 22 mbps which is well within the working the capability of any HDMI cable.