Yes. I think you are exactly there. One minor issue is still open: if it is better to connect the MUX and the Buffalo (via the OTTO) by PCM or SPDIF. This issue can however be tested empirically after boards have been installed.
Yesterday I did the microscopic soldering surgery to tap PCM and DSD from the Denon and I hope sound will come out..........
Nic

I do mean to choose between PCM (4 wire) and SPDIF (2 wire). They are both interface formats.
If I have not understood completely wrong PCM is the name of a group of protocols in which data, bit-clock, and word-clock are transmitted on separate channels.
I2S is just one of several PCM standards (another is for example called EIAJ).
DSD is different from PCM and SPDIF standards in the fact that the left and right data, as well as the bit clock, are transmitted on different wires.
In SPDIF all the information has been "compressed" into a single channel and is typically down-sampled in the process so that what you get out on the back of your transport (in SPDIF) does not have the resolution you paid for when you bought your SACD and DVD-A.

Thats why we want to tap the "original" high-resolution signal and redirect it to the Buffalo.

I will post a photo tonight of how I'm trying to tap the PCM (i.e. I2S) and DSD signal from the Denon 1920.

At the moment its not really working so I hope to get some suggestions from Russ, Brian or MrMajestic on how to fix it

Nic

If you are trying to tap DSD and I2S on Sony SCD-XA5400ES, you can get these signals from Pin 1, 2, 3, 4, 5, 6 of DSD1796. But you do not have to solder all wires on these pins directly: trace back from these pins, you will find there are 6 test-point-like solder points between DSD1796A and the clock. It is much easier to tap signals from there.

I modified the 5400ES by 1. swapping DSD1796 by DSD1792, 2. all down stream OPS: THS4032IDG4 x 2 (use I grade for wider temperature range) --> LME45720 x 3. Next step is to squeeze a Buffalo32 in there

Edited by user Friday, May 15, 2009 2:07:57 PM(UTC)  | Reason: Not specified

For me the Sony SCD-XA5400ES seems a little bit of an overshoot (>1000$) for my needs as I hope to get the same signal quality/resolution from a 100$ Denon....
Nic

What am I doing wrong? Any pictures of a successful PCM tab?
Nic

Edited by user Friday, May 15, 2009 2:58:37 PM(UTC)  | Reason: Not specified

Yes I seem to recall needing to change the PCM mode from I2S to LJ or RJ, I just can't remember which.

Its been a while since I have played with it.

If I get a chance I will post my findings.

Cheers!
Russ

You would need special firmware. I can arrange that for you once I find which mode it is.

One other option would be to use the otto to switch between SPDIF and DSD instead of PCM and DSD.

You should be able to find a TTL level SPDIF on the board. Just run this to D1 on the BUF32S.

You can switch between TTL level SPDIF and DSD without changing any switch settings or (I am pretty sure) resetting.

Cheers!
Russ

Edited by user Saturday, May 16, 2009 5:33:39 AM(UTC)  | Reason: Not specified

Can the ASRC module be used to switch between left and right justified I2S?
Just wondering as there seems to be a lot of in and output options.
Nic

I just received the ASRC module and will try to set it up tonight. I have gone over the ASRC manual and (and, briefly, the data-sheet for the IC) and I think that I know what to do.
I have one question: will the bypass header allow me to restrict the function of the board to do format conversion (i.e. from RJ to I2S) while maintaining the original sample rate and bit-depth?
In the future I would like the AC1 to tell the sample rate of the media I'm playing and with the resampling by the ASRC my CD's would look terribly hig-rez
Thanks,
Nic

Bypass does not do anything but pass straight through, so any sample rate is OK, but keep in mind you may need to get the master clock (depending on the target DAC) from the source.

Cheers!
Russ