NEW CANEVER AUDIO® THE UNIVERSAL I2S-INTERFACE

 

CanEVER AUDIO® writes: "Beside the fact, that in the area of digital audio meanwhile streaming from internet platforms like TIDAL, QOBUZ and others is the most popular way of listening to music at home (beside listening to analog records of course....), there is a group of customers, which still enjoys listening to CDs. They even invest in new high quality CD transports to get the best from those CDs."

As another interesting fact, the audio industry promotes more and more the I2S digital format over the established S/P-DIF to exchange the audio data between a CD-T and a DAC.

Unfortunately, there is no international standard as well for the physical connectors as the way in which the individual pins of those connectors are coded. In the end, each company offering an I2S output on their CD-T uses a proprietary solution to connect to their in-house-built DAC, which comes with a proprietary input connection too. Customers looking to buy a CD-T and a DAC from different companies have no chance to make a choice of their own – they are locked into proprietary solutions!

Also customers, which already own a high quality DAC and now want to invest into a CD-T with an I2S output realize, that their DACs usually do not offer an I2S input at all.

CanEVER AUDIO® always looks for smart solutions and is proud to announce, that all the DACs in the CanEVER AUDIO® family now offer an optional I2S input, which can be individually configured with the connector needed to interface with a number of CD transports from different vendors as PS-AUDIO, PROJECT or AYON AUDIO just to name a few.

Let ́s look into the I2S connection in more detail now.

Since the early beginning of digital playback via CD ́s, the original signal read by the laser from the disc is coded in the so-called I2S format. Although these high quality digital signals are available by definition, the digital data transfer between CD transports and DACs is usually based on the S/P-DIF format. While the I2S format sends different digital data on separate wires from the transport to the DAC, in the S/P-DIF format all those different data lines are “modulated” into ONE combined signal, which then is transported on one simple coax (RCA) cable.

Inside the receiving DAC, those different signals have to be “demodulated” again. The whole process works similar to that in the (analog) video domain of former times, where in the studios mainly the three different color signals for RED, GREEN and BLUE (RGB) are transported on three separate cables between a video source and a screen or projector. In many basic home applications the video signal based on the three different color information are “mixed” together first and then sent out and transported via one single coax cable.

In both (very different applications) the reason for transporting the different signals on separate cables is to reach a better signal quality on the receiving end of the system.

While the above described RGB signal transport has been in use in the (analog) video industry for many years and was very popular in those days, the use of the higher quality (digital) signal transport of I2S data in audio systems was more of a niche application in domestic use for many years. Interesting enough, the Italian company NORTH STAR DESIGN offers an I2S connection between their CD-T and DACs since 1998 (!!) using RJ45 connections and network patch cables for the data transport.

Recently, several companies as PS-AUDIO or PROJECT “rediscovered” the I2S format to connect CD transports to DACs. Unfortunately, there is (still) no international norm of any kind, about which connectors and/or cables to use at both ends of the signal chain. This led to several proprietary vendor specific implementations for the I2S signal transport between a CD-T and a DAC. Obviously none of those implementations allowed customers a free choice of a CD-T and a DAC as the I2S connections work between the products offered by only the same company.

The situation improved as more and more companies decided to use physical connectors and sockets based on the HDMI standard. While this in the end allowed customers to use standard HDMI cables to connect a CD-T and a DAC, the coding of the different pins inside the HDMI connectors still is based on proprietary solutions. So customers still have a rare chance to mix between a CD-T and a DAC from different vendors for I2S signal transport.

Here comes CanEVER AUDIO® to offer for the first time a very flexible implementation for almost any kind of HDMI based implementation - or other connectors - for the transport of I2S data. This feature allows customers using CanEVER AUDIO ZeroUno DACs to connect to almost any CD-T with an I2S output based on HDMI and several other types of connectors currently offered on the market.

For better understanding, following there is a brief description on how the I2S signals are encoded. Basically, the i2S connection is based upon 4 different signals:

  • DATA data
  • LRCLK Left/Right word clock 
  • BCLK Base Clock
  • MCLK: Master Clock

(Usually the Master Clock is not needed in the interconnection between units).

On the contrary, in the S/P-DIF all 4 signals are coded into one signal, that at the receiving unit is again decoded into original signals, i.e.: DATA, LRCLK, BCLK, MCLK.

The management of the 4 basic signals separately, compared to the S/P-DIF protocol, eliminates the need for encoding and decoding the different signals at the start and the end of the signal chain, usually leading to better overall signal quality.

Unfortunately, the i2S interface is not standardized and there are many variants, different from one vendor to the other.

Aside from the different handling of the data, there are several different physical connectors on the market to link a CD-T and a DAC based upon:

  • - 1x 19 pins HDMI connector (balanced signals) 1x 8 pins RJ45 connector (unbalanced signals)
  • - 1x 5-6 pins DIN connector (unbalanced signals)
  • - 1x 9 pins D-SUB connector (unbalanced signals)
  • - 4x BNC connectors (unbalanced signals)

Again, the pinout is usually different from one brand to another!

Last but not least, the market is moving to a (almost final) de facto standard: the HDMI physical interface, with balanced signals transmitted.

Based on that, there are (still) two configurations for the pinout implemented inside the products of different vendors and at the time of this writing it is not clear, which configuration will be the “final” one or if there will be ONE solution ever.
Family #1: Sonore, PS Audio, Mola Mole, M2Tech, Aune, Denafrips, Holo Audio, Empirical Audio, Audio- gd, K&K Audio, Musica Pristina, Channel Islands Audio, Sthal~Tek, DiDiT High-End, Matrix,
HiFime, X-Sabre

Family #2: Project, Pink Faun, Audiobyte, Rockna, Wadia, Singxer, SMSL, LKS, Gustard Note All trademarks and registered trademarks are the property of their respective owners
To be able to interface almost any CD-T present on the market today, a universal i2S interface is available for the whole ZeroUno DAC family by CanEVER AUDIO®.

It is possible to implement e.g. one HDMI socket into any ZeroUno DAC model in exchange of one of the four existing digital input. Based on the choice of CD-T the customer has made, the connection can be configured individually.

Even a retrofit is possible on most existing ZeroUno DACs!

Fig.1 The ZeroUno DAC family with the standard proposal for the i2S: RCA SPDIF, Optic, USB, i2S HDMI
Fig.2 The ZeroUno DAC family with the Neutrik HDMI socket on the left to interface the HMDI sources
To change the configuration of the HDMI pins between the (currently) two most popular implementations, it is possible to switch from the family #1 to the family #2 by only moving the connector inside the unit from one socket to the other.


Beside HDMI, the CanEVER AUDIO® ZeroUno family of DACs can interface to a CD-T based on RJ45, DIN or D-SUB type of connectors as well easily by exchanging one of the Neutrik connectors at the rear panel.

Even more than one I2S input is possible e.g. using different physical connectors and cable configurations.


For any kind of uncommon pinout, the interface inside the CanEVER AUDIO® ZeroUno family of DACs is equipped with an integrated “patch panel” for each single wire, so that the mapping of any individual configuration of cables / signals can be adopted easily.

The sources with an uncommon pinout must be specified at the time of ordering, so the patch panel can be setup prior to shipment. The patch panel configuration can be changed later at any time by factory service.


Appendix


List of the device that the ZeroUno i2S interface is able to emulate.


Same example of configurations