I2S Interconnects, Fred, Jocko, Elso, anyone?

[mefistofelez]

I can access I2S interface, but need to connect it to a DAC, using about 20 inches long interconnects.

Can I just use a coax, or is this a naive approach and I would need some conditioning on (both) end(s)?

Thank you,

M

[tiroth]

The problem with coax is that you will have trouble driving a 75-ohm line, and then you still need to restore the 5V logic level.

If your logic is slow enough (HC or slower) you may be able to get away with 100-ohm ribbon cable and then play around with the termination if you have a fast scope. I'm sure an expert will contradict me now.

[borisov57]

Hello,

I have made such connection with flat cable driven by hc logic and series terminated with 50 ohm. It serves me good, altough flat cable impedance for GSGSG type connection is around 100 ohm.

[Elso Kwak]

Originally posted by mefistofelez
I can access I2S interface, but need to connect it to a DAC, using about 20 inches long interconnects.

Can I just use a coax, or is this a naive approach and I would need some conditioning on (both) end(s)?

Thank you,

M

Hi M.
Please have a look at this post and below.
http://www.diyaudio.com/forums/showt...220#post249220
These 50 Ohm coax cables are 80 cm (about 31 Inch ) long in my situation!

[tiroth]

Elso,

For coax, isn't longer often better due to the cable's lossiness damping any mismatches?

Thanks for pointing out that post on line drivers.

[Elso Kwak]

Originally posted by tiroth
Elso,

For coax, isn't longer often better due to the cable's lossiness damping any mismatches?

Thanks for pointing out that post on line drivers.

Hi Tiroth,
Jocko I believe, never goes below 1 meter.
Has to do with reflections if I understand correctly.
Ideally the length of the cable does not matter except for losses.
My ideas came from Horowitz and Hill, The Art of Electronics, Cambridge University Press, chapter 9, digital signals and long wires. See also sub chapter 13.09 Transmission Lines.