? on the I2S standard regarding transport to DAC

KnowTalent · « **on:** 2 Oct 2010, 10:55 pm »

With PS Audios perfect wave transport/dac they claim superior performance when utilizing the I2S connection which, if I understand correctly, seperates the data and clock signals from the transport feeding the DAC...

My question is....in a garden variety integrated cdps such as the mass produced Arcams, Cambridge Audios, etc... do they utilize I2S or S/PDIF to carry the signals?
I remember seeing a picture of a player in one of the Hi-Fi News CD player archive downloads and one player actually had a S/PDIF cable running from the transport to the main circuit board. Is this common and if so if I2S is noticeably superior why don't more people incorporate it into their products? Is it that expensive????

Does any manufacturer of "lower priced" integrated models use I2S internally???
Inquiring minds want to know

JohnR · « **Reply #1 on:** 2 Oct 2010, 11:13 pm »

I2S isn't designed for going outside the box, it's for short runs on a board or within a chassis. i.e. between the receiver chip and the DAC chip. Not that it can't be transmitted outside of the box, it's just a signal... but I don't think there's a standard for connector/impedance/levels, is there?

KnowTalent · « **Reply #2 on:** 2 Oct 2010, 11:19 pm »

Quote from: JohnR on 2 Oct 2010, 11:13 pm

I2S isn't designed for going outside the box, it's for short runs on a board or within a chassis. i.e. between the receiver chip and the DAC chip. Not that it can't be transmitted outside of the box, it's just a signal... but I don't think there's a standard for connector/impedance/levels, is there?

sounds like you're kinda asking the same question?
With the "new" assertions of I2S as a "superior" data pipe line between transport and DAC seperates, I am unclear if I2S is the standard for data transfer in intergrated units?
I don't recall ever reading a manufacturer or test review stating whether SPDIF or I2S is the standard for internal data transfer in integrated units and I'm curious to know

JohnR · « **Reply #3 on:** 2 Oct 2010, 11:40 pm »

Well, I was allowing that there's a standard that I'm not aware of... but since PS Audio say "PS Audio has searched for a long time for the perfect cable to transfer I2S data. Some manufacturers use CAT-5 which is the cable your computer connects up to the internet. We took one look at this method and rejected it out of hand," I guess there's not. So by the looks of it you'll only be able to use "I2S" between those two units, and not with anything else.

I'm not an expert but the chips I've looked at use I2S - it's just two clocks and a data line - so I suspect that most units use it internally, assuming they're using off-the shelf chips.

KnowTalent · « **Reply #4 on:** 2 Oct 2010, 11:54 pm »

Quote from: JohnR on 2 Oct 2010, 11:40 pm

Well, I was allowing that there's a standard that I'm not aware of... but since PS Audio say "PS Audio has searched for a long time for the perfect cable to transfer I2S data. Some manufacturers use CAT-5 which is the cable your computer connects up to the internet. We took one look at this method and rejected it out of hand," I guess there's not. So by the looks of it you'll only be able to use "I2S" between those two units, and not with anything else.

I'm not an expert but the chips I've looked at use I2S - it's just two clocks and a data line - so I suspect that most units use it internally, assuming they're using off-the shelf chips.

thanks

silver_strings · « **Reply #5 on:** 3 Oct 2010, 07:17 am »

Maybe if the bigger companies got behind it and made a standard connector and products using this I2s connector it would be more widely used. My Audio Alchemy DDS Pro has I2S which I use to connect to my Audio Alchemy DAC both also have spdif output and input,there is definitely a big difference no question the sound is the closest I've heard a CD player sound to vinyl but even better in my opinion because you also get the detail and clearness of CD's.

satfrat · « **Reply #6 on:** 3 Oct 2010, 08:11 am »

Considering Empirical Audio also uses I2S connections for their products, you might want to ask Steve Nugent over at Empirical Audio Circle for his input. Just a thought,,,

Cheers,
Robin

JohnR · « **Reply #7 on:** 3 Oct 2010, 11:11 am »

Steve's site says (my bold):

Quote

Empirical Audio standard I2S interface uses 4 signals and 4 returns and the RJ-45 connector. It is compatible with I2S on several other manufacturers DACs, including Stello, Perpetual Technologies and Northstar, as well as our own Overdrive DAC.

I have a Teralink USB convertor that outputs I2S, which I thought I might try using to connect to a miniDSP one day. However miniDSP have since come out with their own USB-to-I2S board so if I ever get to it I'll just use that.