I2S Cable length?


#1

Hi

Does anyone know what cable length is recommended for a I2S HDMI cable between transport and dac. I was thinking of 1.0mtr. Is this length OK or would a 0.5mtr make any difference?

Thanks.


#2

Search the forum threads. This has been discussed a lot.


#3

Sorta usually driven by how close they are on the shelves. If they’re close enough, and you don’t think you will ever want them further apart, get a half. I think one consensus is not to stack them just so you can use a shorter cable - the potential interference is likely worse than any difference between .5m and 1m.


#4

Here is one brief previous discussion which may be of help: clicky


#5

Ok, here’s what I found just recently:

  1. Started with stock, supplied in the box PS Audio cable. Good, clear, neutral sound
  2. Moved DMP 20 ft away using a cheap hdmi BlueJeans/Belden. Sounded cloudy, dull.
  3. Moved the DMP closer and used a 9ft PS Audio AC12 (no longer available). Indisputably the best sound.

#6

I would be concerned with that 9 ft. length. it is funny that you prefer the AC-12 to the stock cable they supply with the DMP. Both Arnie and Paul prefer the new cable to the AC-12.


#7

I confess I don’t like the new supplied cable. No cable has displaced the HDMI AC-12 in my system.


#8

funny? It’s a laugh riot! All seriousness aside, I didn’t say I’m right. I just stated my experiences and taste.


#9

Yes that is true. Everyone’s systems and tastes are different. Just look at the reactions to the various DMP software releases.


#10

It’s been stated in the past that the I2S cable should be a maximum of 3M, so it’s not surprising a 20’ length didn’t sound good.


#11

I’ve found lots of opinions and even equivocations by those who we might expect to “know”, but no useful rule.
If asked, I would recommend one just use what came in the box and spend the rest of the money on music or a night out.


#12

There isn’t a rule as such.
I2S was developed as a chip to chip bus for PCB’s and as such was only good for a few inches. To transmit from box to box in a hifi situation the source component has a line driver stage to allow this. The distance that this will cover depends on the line stage design.

They should all be good for several meters though.

If you want more info, check out the i2s interface design PS Audio published on the web for anyone to use commercially and the TI line driver chip it used. The TI data sheet will probably give more on what that particular item is capable of doing. It was a smart move by PSA offering a HDMI pin out scheme and line driver schematic. Several manufacturers have adopted this pin out which makes them compatible with PSA equipment, Audio GD for one. The latter sell a line driver board with this HDMI socket pin out, which can be connected to a SBC like the Raspberry Pi. This can then be plugged into a Stellar GCD etc. I will get around to playing with one of these soon I hope.
The i2S output on SBC’s is not the best, Allo make the “kali” which is an i2S re-clocker that sits between the SBC and the line driver for better i2S output.
Sorry for the additional waffle, some folks might be interested in this aspect, and unaware of the possibilities.

My intention is to build a music streamer/server based on a SBC. This will be hard wired to my Routter/hub using Gigabit Ethernet cable and a NAS drive attached to the HUB for file storage. the SBC will be connected to the Stellar GCD using i2S. So not a USB or SPDIF item in the chain. My CD transport has i2S, but on a 5 pin mini XLR, I am considering converting this to HDMI socketry. Then it should be possible to adapt an HDMI switcher (with remote) to go between the CD and File sources to feed one or the other to the single i2S input on the Stellar GCD.


#13

Thanks!