Multichannel digital IN/OUT mod or board?

[jheoaustin]

Folks,

I wonder if there are any mod business modifying AV receivers/pre-pros to get S/PDIF or other easy-to-DIY digital format for some post-processing. Do you know any?

If not, I'd like to try it myself, but don't have good schematic/PCB experience. So, I am looking for a good off-the-shelf or kit solution on this. Get I2S inputs from audio DSP inside the receiver and outputs S/PDIF, AES3 or SDIF-x. I also need multichannel receiver board to receive the signals from the transmitter. Please let me know if you know any such thing.

I am looking forward to your sharing experiences. Thanks in advance.

[OzOnE_2k3]

Hi,

There is a great thread started by Brian Brown with schematics for some transmitter and receiver boards which might be of some help to you....

High Resolution Multi-Channel Digital Interface

The "gerber" files could be sent to a PCB manufacturer so they could make the boards for you. The difficult part might be soldering the chips (easier with a hot-air machine), and also finding out where the I2S pins are on your amp / pre / player etc.

This interface allows you to send many channels of uncompressed audio using only two pairs of wires in a Cat-5 cable. You can get most of the chips as free samples from Texas Instruments (I recently received mine, but I'm not sure what to do with them yet!)

If something like this can send signals for even 5 meters, I think it should be made a standard for all AV amps, DVD players, and sound cards. If I remember rightly, the boards can send audio for quite a bit further than 5 meters!

(I was hoping to modify my Audiotrak Prodigy 7.1 sound card with one of these transmitter boards, but I can't get rid of the glitches I'm getting on the ASIO outputs.)

Hope that helps,
OzOne.

[rfbrw]

Originally posted by OzOnE_2k3

You can get most of the chips as free samples from Texas Instruments (I recently received mine, but I'm not sure what to do with them yet!)

This is the kind of thing that really pisses off people who do this stuff for a living. These chips are hardly a kings ransom. Buy them.

[rfbrw]

Originally posted by jheoaustin
Folks,

I wonder if there are any mod business modifying AV receivers/pre-pros to get S/PDIF or other easy-to-DIY digital format for some post-processing. Do you know any?

If not, I'd like to try it myself, but don't have good schematic/PCB experience. So, I am looking for a good off-the-shelf or kit solution on this. Get I2S inputs from audio DSP inside the receiver and outputs S/PDIF, AES3 or SDIF-x. I also need multichannel receiver board to receive the signals from the transmitter. Please let me know if you know any such thing.

I am looking forward to your sharing experiences. Thanks in advance.

AKM make an 8 channel SPDIF transmitter and have an evaluation board for it .

[Pulse-R]

Originally posted by rfbrw
This is the kind of thing that really pisses off people who do this stuff for a living. These chips are hardly a kings ransom. Buy them.

Hi rfbrw,
I understand what you are saying, but to buy 1 or 2 qty of I.C.s is nearly impossible for DIYers.

I know when I want more than a handful, I can buy them - no problem. But what about if you want to only get 1 unit - hardly worth paying $25 shipping for a single $2 part.

[OzOnE_2k3]

Hi,

I didn't mean to offend anyone with the "free samples" thing, but I thought the whole point was that these large companies are prepared to offer samples to promote their products and for people to evaluate a prototype design etc?

Thanks for the info on the AKM chip though. It looks like it would be easier to make a PCB for and possibly easier to solder etc.

OzOnE.

[sfogg]

"I wonder if there are any mod business modifying AV receivers/pre-pros to get S/PDIF or other easy-to-DIY digital format for some post-processing. Do you know any?"

I have 3x S/PDIF output boards available, working on the 3x S/PDIF input boards and am waiting on parts. I am using them for 3x S/PDIF out from the Behringer DCX2496 to stay digital into a XR55 to keep it digital through the amps.

http://switch-box.com/Home.html

Shawn

[dwk123]

The Twisted Pear boards can probably be used for this. Check out the end of the thread started by rossl for examples of hooking up the xmitter to an Oppo universal player. It's only stereo, but the other signals are available as well, although finding room for 3 xmitter boards may be tricky. Note that the internal format is left justified rather than I2S, but the Twisted Pear xmitters handle it just fine. The cool thing about using the Oppo as a signal source is you get everything as multichannel PCM, including DVD-A and SACD, and of course normal DD/DTS dvd soundtracks.

The Panasonic SA-XR10 is probably the easiest reciever to get signals out of, since they're on a ribbon cable between the DSP and the amp board. This is not 'raw' though - all the receiver DSP has been applied including volume control, so it may not be ideal. The other Panny XR series receivers have these available as well, although they aren't so convenient - still possible though as sfogg shows.

On the input side, the Delta 1010 sound card (NOT the 1010LT) has all the I2S signals routed to a DB-25 breakout connector. This should be a fairly easy way to get such a multichannel signal set into a PC, and then back out again. You wouldn't necessarily even need the spdif link in that case if the two units were close enough. Other than that, the Lynx LS-AES has a bunch of AES digital inputs that should handle SPDIF as well.

[jheoaustin]

rfbrw,

I seem to have no luck in finding the AK4101A EVM, which looks just like the right module for me. I contacted AKM to get info., and a Texas disty called me to make sure I live in CA, due to my unchanged cell # I submitted to AKM. He said he would hand me over to a disty in CA, then nothing afterward.
Do you have any information on getting this board from the right disty?

[rfbrw]

The only contact I have had with AKM was through DIP International but they are local to me in the UK.