I have the following:
1. Buffalo32s v1.1
2. 4:1 MUX v1.01
3. USB receiver v1.1

and I'd like to experiment with both I2S and S/PDIF. As a newbie to digital, pls let me know if the following wiring and settings are correct:

For I2S:
USB DO to MUX +
USB GND to MUX -
and short DO and DI on the USB Receiver together, plus set Format header to I2S.

MUX GND to Buffalo32s GND
MUX BCK to Buffalo32s DCK
MUX LRCK to Buffalo32s D1
MUX DOUT to Buffalo32s D2
and set SPDIF switch on Buffalo32s to ON

---

Now for S/PDIF:
USB DO to MUX +
USB GND to MUX -
and set Format header on USB Receiver to S/PDIF.

MUX SPDIF + to Buffalo32s SPDIF
MUX SPDIF - to Buffalo32s GND
and set SPDIF switch on Bufflao32s to 1.

---

More questions:
1. What's the difference between Consumer Level SPDIF and TTL Level SPDIF? and if I use a coax out (RCA or BNC) from a typical CD player, is that S/PDIF or TTL? How can I determine that?
2. If my CD player outputs S/PDIF (either Consumer or TTL level) the 4:1 MUX, can I expect I2S (or PCM) output from the 4:1 MUX?

I think that's enough question for one day.

Thanks in advanced for any feedback!

There are no stupid questions in your post. :)

If your using the MUX you feed it only SPDIF.

I would use a series and shunt resistor on the USB modules SPDIF output to bring the TTL level down to consumer. 374R on output with 93R shunt to GND will work nicely.

The MUX won't care if the SPDIF is TTL or consumer, but your source may not like driving TTL levels into 75R. And I would not recommend doing that unless you know it can take it.

For I2S direct into the buffalo you have the right idea. In this case you do not use the voltage divider on DO.

Cheers!
Russ

You are not stuck with it. :)

But you can only feed the MUX SPDIF. :)

The MUX can and does output both SPDIF and I2S. :)

I would use the I2S out of the MUX and the SPDIF into it. :)

Cheers!
Russ

Edited by user Tuesday, October 13, 2009 5:30:42 PM(UTC)  | Reason: Not specified

Russ, I think I can put all the questions aside for now. I just ran a very simple test and I am not getting a lock: I connected Coax out from my CDP directly to Buffalso32s' SPDIF in. All switch settings are factory default, A_Mute is on tho.

I use a 3.2VA 9V transformer at the moment as I am waiting for a more powerful one. Is that a problem?

Any insight?

Edited by user Tuesday, October 13, 2009 7:41:36 PM(UTC)  | Reason: Not specified

Right you will not want to whole divider network if you are doing I2S. It only applies to SPDIF and only into the MUX or SPDIF input of the Buf. In short, if your sourcve will see 75 ohms load, use the divider.

If you go into a TTL input such as D1 on the BUF then you don't want the divider either.

The SPDIF switch is closed?

Ok, I tested with another CDP and it works. Seems pretty odd. One work and other doesn't (but it works with other DAC). Any insight?

Edited by user Saturday, October 17, 2009 4:07:08 PM(UTC)  | Reason: Not specified

Is it a DVD player? If it is, it could be that it is producing LPCM and not PCM.

Edited by user Saturday, October 17, 2009 4:20:48 PM(UTC)  | Reason: Not specified

Found the problem: the digital output ground wire was broken inside the CDP.

Everything works beautifully and it is sound-to-die-for!!!

Now only if I can find a 3-lead 3mm common-cathode bi-color LED...