Quote:
Originally Posted by
punk_guy182 
I'll see what sounds better between USB and TOSlink on the Digital Interface.
I hope that I won't have to invest in pricey USB cables to get the best out of this unit.
I'm not familiar at all with the I2s standard but I read somewhere on the Audio-GD website that it would be I2s compatible. Does anyone know what are the benefits of I2s over S/PDIF and if the RE1 can recognize it?
My experience is that TOSlink is not a good audio interface. I think the issue is that the necessary chips out there in the marketplace are not that good. Anyway, I have always preferred the sound from S/PDIF.
Benefits of I2S:
I2S is the means by which the DAC chip communicates with the outside world. In other words, it is the DAC chip’s own “native” language. Somewhere in the digital playback chain music data is converted from one format e.g. raw data (if being read directly from CD) to I2S format to then be processed by the DAC chip. In my set-up, I store music on a HDD in wav file format. The wav is then transferred by the music player software (cPlay or whatever) to a digital interface device (like the Musiland) by a USB cable. The interface device will attempt to recover the data and re-clock it using its own internal clock so that the wave form can be properly reconstituted by the DAC chip at a later time. The digital interface device, however, typically has to convert the data (once again) to some format in order to talk to the DAC chip. If, however, the interface device is able to convert to I2S and then transmit this to the DAC chip then one can see that some conversions are eliminated. This kind of architecture also lends itself to the idea that the DAC chip is effectively being slaved to the (precision) clock in the digital device.
What is a further development is for the digital interface device to control what the computer is doing to some degree. This is what Musiland and M2tech try to do. The ideal being that all three elements (DAC, interface device, and PC) are more or less tied together and running off the one precision clock somewhere in the chain (usually the interface device). However, what Audio-GD (I think) has done in the DSP-3 is avoid the issue of PC control preferring to focus on other areas. I can understand this if only because I can see that the murky waters of PC software development are expensive and deep. Of course Audio-GD could do what Empirical Audio has done and license the software from M2tech. But that could potentially add another US$300 to the cost if one were to use Empirical Audio as a yard stick. But you never know, there will likely be a DSP-4 one day..
RE1:
I don’t know if the RE1 can accept I2S from the DSP-3. According to Kingwa, the DAC-19DSP can. Perhaps you could ask him.
A further note:
It is said that I2S was never designed for “distance travelling”. What this means is that it was never meant to connect separate devices together and that if you do so you are likely to corrupt the I2S signal. I don't have the experience to make a comment. Nevertheless, I am keen to give I2S a go.
Edited by Audio Bling - 7/16/10 at 12:33am
