Hiface USB-I2S moduleI2S is a digital communication protocol that offers lower jitter & more direct method than SPDIF. If implemented correctly these advantages can be realised. The difficulty is that I2S is not meant for box to box communication, more for pcb board communication. Most DACs do not have external I2S connectors as there is no standard wiring or connectors.
I supply a Hiface USB-I2S module for feeding I2S into the digital input of DACs. This is available to people that can wire in the I2S connection to their DAC. The I2S connection is meant to be kept as short as possible with good HF cable & connections.
This 24/192 asynchronous USB transport using low jitter clocks with optimised power supply feeding I2S directly to a DAC should result in the best computer audio available today.
This Hiface version is I2S output only with NO SPDIF outputs. It will have PS connectors that can be connected to the supplies of choice; on-board 3.3V regs, batteries or external PS. No power is drawn from the USB cable so no reliance on the often variable quality of computer PS & therefore no need for so called "audiophile" USB cable - a reasonable standard USB cable will be as good as an expensive one.
The new AchoDac & Buffalo DACs based on the famous ESS DACs already have digital inputs for I2S. Other DACs may need to be modified to expose the I2S signal input lines.
The AckoDAC is a new line of DACs based on the range of DAC chips from ESS. This was jointly developed by Acko & myself. The first of these DACs is on offer here: http://ackoav.spaces.live.com/