[sdiy] ADAT and multichannel AES/EBU

[peff 2cv]

Hello Magnus,

ADAT specs are available on the Alesis website www.alesis-semi.com and the 
chips are optorec and optogen. If you can get your hands on these, it bis a 
simple solution.

As for AES/EBU Cirrus and a couple others have interface chips. No 
multi-channel chips though--the problem is each AES/EBU stream is 
clock-recovered and dejittered at the receiving end. Some ASICs use one 
channel as a "master" clock-recovered timing signal and slave the rest to 
that but then there is the issue of sample "slips" due to different timing 
between streams. Gets messy. If you want the AES/EBU route, buy Cirrus 4816 
(I think) and duplicate for as many stereo pairs as you want.  IF you are 
really sadistic, this can be done in an FPGA using DLLs or external PLLs for 
clock recovery. Xilinx has app notes and example code for CDR (clock data 
recovery) which could be a basis for a solution. AES and EBU websites have 
detailed specs for the interface--interesting, but not trivial.

HTH,

Peff


>From: Magnus Danielson <cfmd at bredband.net>
>To: synth-diy at dropmix.xs4all.nl
>Subject: [sdiy] ADAT and multichannel AES/EBU
>Date: Sun, 09 May 2004 00:03:35 +0200 (CEST)
>
>Dear all,
>
>I am currently looking around for multichannel (raw sample-noncompressed)
>digital interfaces. Among those I am looking to find the ADAT 8-channel 
>format
>specs. I also beleive there is a multichannel AES/EBU format. I am aware of 
>the
>MADI format and got that spec. lying around here. I am also aware that you 
>can
>embedd AES/EBU audio into the BT.656/SMPTE 259M format as well as it's 
>higher
>rate variants.
>
>What else can you put my attention on? Preferably with specs and all.
>
>Cheers,
>Magnus

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