Transformer coupling is done all the time for AES/EBU, with its biphase-mark data coding, but is that also true for S/P-dif? We see either TTL or optical, but generally neither of those two is ac-coupled, isn't that so? I'm trying to remember the spdif waveforms, are they biphase-mark coded as well?.
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Thanks,
- Win
Winfield Hill skrev:
existing
-Lasse
Would this setup work? Ie sending AES/EBU audio data over cat.5 cable.
Soundcard "S/P-dif,AES/EBU" TTL-level | \\|/ Line driver (LTC485 or similar RS-422 compatible driver) | \\|/
1:1 Transformer (Like Pulse H1012) | \\|/ < 100m cat.5 ethernet wireing | \\|/ 1:1 Transformer (Like Pulse H1012) | \\|/ Line receiver (LTC485 or similar RS-422 compatible driver) | \\|/ Toslink transmitter (TOTX179P or ekvialient)The LTC485 is specified at 2.5Mbps maximum. But maybe there is some margin to use if cable runs are short (
Done all the time, see epanorama.net for winding cheap aes/ebu transformers. If you have transformers, you already have galvanic isolation. choose a driver /receiver that is pin compatable with faster versions, if you run into probs. probably stuff already made on the Kramer site
martin
I have seen epanorama's spdif stuff. But there is no schematic info on aes/ebu. Anyway should I place a 100 ohm resistor parallel to the output of the line driver?, or can I just wire the line driver straight to a pulse transformers primary side from an old ethernet card?
I think I'll have to do some "birdnest" wireing to test things.. ;)
specified at 2.5Mbps maximum. But maybe there is some margin to
just been brushing up on spdif etc, been some time, but
"The CS8416 includes an AES3/SPDIF digital audio receiver. The receiver accepts and decodes bi-phase encoded audio and digital data according to the AES3, IEC60958 (S/PDIF), and EIAJ CP-1201 interface standards."
If its biphase, transformers are ok in my book
martin
existing
SP/DIF is in effect simply a subset of AES/EBU IIRC.
I believe it has no trouble being transformer coupled. Although I fail to see any good reason to do so since the shield connection is also ground anyway.
Graham
snip
thats the one!
martin
existing
I suggest you follow the advice that you'll typically find on one the Crystal devices datasheets ( made by Cirrus Logic ) .
Don't bother with transformers. Not necessary unless galvanic isolation is a must.
Graham
someone said Spice. It can show you a rose garden and then on the breadboard it's all weeds.
Good bit of breadboarding........... yep
SPDIF is just a digital signal, nothing special about it , unless you go to stereophoole.com, for a lateral quasimodulated LSB with quantum dither
martin
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