[sdiy] A new project in the planning stage...

[Michael Bacich]

On Oct 16, 2006, at 10:19 PM, James Patchell wrote:

> However, finding info on how to make my own ADAT interface has, so  
> far, proved difficult at best.  If anybody knows where I can find  
> specs on the ADAT protocol, that would be, hopefully, helpful.

Alesis has a chip-making division that makes all-in-one chips that  
will convert either eight channels of serial digital audio to ADAT  
data for connection to an optical port, or eight channels of audio in  
ADAT format to eight separate serial digital audio lines.  This  
Alesis chip is used by many other manufacturers to solve exactly the  
problem you describe.  This division of Alesis has a separate company  
name, and a separate website, but I can't remember what it is right  
now.  It;s probably almost impossible to buy the chip in hobbyist  
quantities, but maybe you could get Alesis to sample you a few?  Or  
prossibly you could order it as a "repair part" from one of the  
companies who use it in their products.  For instance, it is used by  
Behringer in their sweet little 8-channel analog to ADAT/ADAT to  
analog unit, the ADA-8000.  I think Fostex also use the chips in some  
of their digital audio products, such as the VM-200 digital mixer.  I  
used to have data sheets for these chips somewhere around here, but  
I'm not sure what backup CD I put them on, unfortunately.  Maybe  
Google can help you find them.

Mike B.

P.S. -- Update: the company is called Wavefront Semiconductor,  
formerly Alesis Semiconductor.  They are based in Seattle, WA, and  
their web address is:  http://www.wavefrontsemi.com   the chips to  
look at are the AL1401G (digital in/optical out, $8.80 each) and the  
AL1402G (optical in/digital out, $9.45 each).  Data sheets are at the  
site.

These chips really work great.  I have several units in my studio  
that use them, and they always work flawlessly.  I use multiple ADAT  
optical signals for my most important interconnections.  I've looked  
at the circuits that are built around them, and they appear to be  
very, very simple to implement.

Let me know if you are going to buy some, and I would be happy to  
chip in on a few if it would help make an order.  The ones with  
digital in/optical out would probably be more useful to me, but I  
could use both types, too.