Long confined to the internal circuitry of audio equipment, the i2S link is now establishing itself as one of the most advanced solutions for the transmission of digital signals in high-fidelity. But what is this connection really used for? How does it differ from traditional digital connections such as USB, coaxial or optical? And why does its implementation vary from brand to brand? Discover the answers to all these questions in our new guide to HDMI i2S in hi-fi.
Long associated almost exclusively with the world of video, the HDMI connector is gradually establishing itself as a player in its own right for hi-fi. Its widespread use began with HDMI ARC, now a must-have on hi-fi amplifiers, active speakers and network players, and more recently with the arrival of HDMI i2S, which extends the possibilities even further. Increasingly present on network players, high-end CD transports and audiophile DACs, HDMI i2S is arousing growing interest among hi-fi enthusiasts in search of the very best performance.
The i2S (Inter-IC Sound) protocol was developed in the late 1980s by Philips, at a time when digital audio was beginning to take hold in CD players and the first digital-to-analog converters. Originally, i2S was never designed to be a consumer interface, but an internal communication bus designed to directly connect the various audio circuits of a single device: player, DSP and DAC. Its particularity lies in its very structure, with separate lines for audio data, master clock and channel selection. This approach avoids signal encapsulation and limits synchronization inaccuracies, offering direct, accurate transmission, ideal for preserving the temporal integrity of the digital signal.
Note from the expert Jitter is a temporal inaccuracy in the transmission or processing of a digital audio signal. Contrary to what one might think, a digital signal is not simply a series of zeros and ones: this data must be read at extremely precise moments, dictated by a clock. When this clock lacks stability, audio samples are no longer converted at exactly the right moment, resulting in slight distortion during digital-to-analog conversion. When listened to, jitter manifests itself as a loss of naturalness and precision. This is why digital links capable of preserving a clean, stable clock, or of clearly separating audio data from synchronization, as i2S does, are particularly appreciated in hi-fi.
For a long time, this architecture remained confined to the inside of devices, as it requires several separate lines and imposes strict constraints in terms of synchronization. However, with the rise of high-end external DACs and the quest for ever-higher performance, thanks in particular to Hi-Res files, manufacturers have sought to get the i2S out of the chassis. The HDMI connector then emerged as a practical solution, thanks to its number of pins and its ability to carry the various lines required by the i2S separately. In this configuration, HDMI enables cleaner, more stable external i2S transmission, closer to the protocol’s original operation. Our new guide to HDMI i2s shows how this standard is revolutionizing the way you connect different digital sources. Ready to take the plunge and optimize the connection between your equipment? Discover our new guide to HDMI i2s in hi-fi.
