I square S

What is I2S? Is every dac and upsampler equipped with them?
I²S is a digital interface specification designed to reduce errors (jitter and suchlike) compared with the more common S/PDIF interface found on most equipment. The I²S interface splits the clock and data signals in an attempt to reduce errors, where the S/PDIF interface uses one conductor and is more susceptible to crosstalk interference between the data and clock portions. Not yet common. Regards, Richard at www.vantageaudio.com
I2S was defined by Philips for connections between chips in digital devices like CD players. It was not intended for use as an interconnection between transport and DAC since the definition was primarily of the signal logic. It was later adapted by manufacturers, originally by Audio Alchemy, for that purpose. It does not "split" the clock and data signals; rather it keeps them separate as they come from the decoder or digital filter. It is the S/PDIF format which combines them.
Perhaps I should have written "separates the clock and data.." rather than "splits the clock and data.."???? regards, Richard.