S/PDIF AES/EBU Transmitter

Here's another new circuit for "approval". I haven't been able to find any schematics using the CS8406, so it's from the datasheet only.

Here's the schematic: http://stiftsbogtrykkeriet.dk/~mcs/SPDIFTX_sch.gif

It should work for both hardware and software mode.

Best regards,

Mikkel C. Simonsen

There have been no complaints, so I drew the PCB. :green:

Here it is:



I guess this board could actually be useful to others than me... If it works I guess I should put the gerbers on my homepage.

Best regards,

Mikkel C. Simonsen

Can you explain the application of that schematic to a simpleton like me?
:guinness:

Yes, it is quite simple. You use the circuit to convert the output from an A/D converter (or perhaps an ADAT receiver) to S/PDIF or AES/EBU format.

This particular circuit supports 16-24 bits, 32-192kHz sampling and stereo or mono mode.

Best regards,

Mikkel C. Simonsen

So it's a D/A converter?

No, more like a D/D converter I guess :grin:

The output from an A/D converter chip is not in a useable format, so you need an extra circuit to convert it to a standard format like AES/EBU.

Best regards,

Mikkel C. Simonsen

A little out of my skill range at the moment, but thank you for the project! I will in the future need a a/d that has a s/pdif!

-jay

So would thjat circuit be considered kind of a protocol conversion thingy?

Yes, I guess you could call it an I2S to AES/EBU converter.

Best regards,

Mikkel C. Simonsen

Same procedure as last time... Here's the receiver part:

http://stiftsbogtrykkeriet.dk/~mcs/SPDIFRX_sch.gif

Best regards,

Mikkel C. SImonsen

On my ADC board (see here) I use a HC541 buffer and a filter on the serial output - inspired by the AD evaluation board manual. Would that be a good idea for the CS8415A transmitter board also? Or isn't the buffer nescessary?

Best regards,

Mikkel C. Simonsen

not 2 sure meself, found this page useful tho: http://peufeu.free.fr/audio/extremist_dac/implement_3.html - mebbe could shed some insight

Here's the latest PCB layout. Without buffers for now...



Best regards,

Mikkel C. Simonsen[/img]

From one of the links above you can back-track and find this :

http://peufeu.free.fr/audio/extremist_dac/spdif.html
and the associated jitter pdf.

who wrote this stuff ?
very cool

Any one have any idea on a design to go from aes to adat lightpipe? I'd love to build something to convert 16 chanels.
thanks,
Peter

butta, when it's all data its not that difficult to get just about any format u want (as far as i can make out!!) - so for adat to aes/ebu u'd need an optogen, some mux (if u want all chans mixed to a single aes/ebu out) and the digital transmitter chip like DIT4192...alotta adc/dac eval brd schems show a ckt for either and aes/ebu in or out...

peesh

[quote author="mesmer"]Any one have any idea on a design to go from aes to adat lightpipe? I'd love to build something to convert 16 chanels.[/quote]
I have posted this schematic before: http://stiftsbogtrykkeriet.dk/~mcs/optogen.gif

You can only pass 8 channels through an ADAT interface (unless they have changed the specs), so you would need two circuits for that. The "optogen" circuit converts from serial data to ADAT. To convert from AES to serial you will need 4 AES receivers for 8 channels. This is the receiver circuit: http://stiftsbogtrykkeriet.dk/~mcs/SPDIFRX_sch.gif

I have designed PCBs for both circuits, but I don't have any ADAT equipment, so I can build the ADAT transmitter, but somebody else will have to test it...

Best regards,

Mikkel C. Simonsen

[quote author="buttachunk"]should there be termination for tr2 ?[/quote]
You mean a 110R resistor accross TR2 in the transmitter? Yes, I think there should be, but Crystal shows a circuit like the one in my schematic in their datasheet...

also, mesmer--- yeah, i would like the opposite-- from adat to aes,,, wonder how we can do this....

Click to expand...

Should be quite easy to do. Do you want to be a beta tester? :wink:

Best regards,

Mikkel C. Simonsen

woop, i meant recgen to receive the adat signal

I'm going to dredge up this old thread to ask the question:

Does anyone have any links to whitepapers about various digital formats, such as ADAT, SPDIF, AES/EBU, etc. ?

What I'm looking for is bit-for-bit timing specs, etc. I want to start playing with digital audio stuff on an FPGA, such as making a 4 spdif to adat converter.

Also I'd like some of the more advanced info, like stuff on hi-res versions of ADAT, like S/MUX or bitsplitting or whatever.