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Mr White's "Opus", designing a simple balanced DAC

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DarrenWadsworth said:
OTTO, that's great! I will need to switch 3 things (sort of), Spdif in from Cd-rom drive, spdif in from external sources and USB in from computer.

2 things are 2-wire spdif in, and I have one spdif reciever.

How would you handle the switching of the three things in a permenant "audiophile" manner?

Thank you
Darren

Just looking for someones opinion on "how they would do it". I have ideas of my own, but I get the feeling that there is a better way that I am not familiar with.

Thank you
Darren
 
I would use the USB module's S/PDIF out, and switch between the three S/PDIF sources (coax, toslink, usb) to feed the receiver. I would then either use a Dawrin (because I have a shelf full of them) with 3 relays installed, or etch a similar 3 relay board and control that with a switch. That way you have one source type, and don;t have to run the S/PDIF all over the case and through a possibly questionable rotary switch.

Or, just do the rotart switch, but definitely use S/PDIF for each. Is you use the WM8804 receiver, you get it's de-jitter feature for the USB source.

Our plan is to make another receiver based on the WM8805 to allow up to 8 S/PDIF sources.
 
I checked with OPPO, and they said the DSD output from HDMI is not encrypted:

"DSD is not encrypted, but it will be converted to PCM when using the analog outputs, or can be left as DSD over HDMI. S/PDIF will not pass SACD audio at all."

This is the player that I am referring to:
http://www.oppodigital.com/dv980h/default.asp

But I am not sure how to setup WM8741 so it can play DSD through HDMI (any ideas?). If this can work with the new Opus, it will be a very good player for less than $200.
 
BrianDonegan said:
I would use the USB module's S/PDIF out, and switch between the three S/PDIF sources (coax, toslink, usb) to feed the receiver. I would then either use a Dawrin (because I have a shelf full of them) with 3 relays installed, or etch a similar 3 relay board and control that with a switch. That way you have one source type, and don;t have to run the S/PDIF all over the case and through a possibly questionable rotary switch.

Or, just do the rotart switch, but definitely use S/PDIF for each. Is you use the WM8804 receiver, you get it's de-jitter feature for the USB source.

Our plan is to make another receiver based on the WM8805 to allow up to 8 S/PDIF sources.

I have your older spdif reciever. Will I need to buy the new one for the USB source to sound great?

Also, I didnt realize that the USB module had spdif output. There isnt a manual or sheet on it.

Will there be any audio degredation, by using spdif and the darwin for all sources instead of I2S?

How much would a darwin be with 3 relays?

I would rather build one. I dont have a shop that I could use to etch a board. its been forever since I did one. Would it dgrade the quality to use a generic pcb and connect the components using quality wire? Plus, I don't know what circuit I need to change the relays every time I hit the switch. Best I could do is run an LED to the front panel to show which is activated

Great Help!

Darren
 
BrianDonegan said:
I would use the USB module's S/PDIF out, and switch between the three S/PDIF sources (coax, toslink, usb) to feed the receiver. I would then either use a Dawrin (because I have a shelf full of them) with 3 relays installed, or etch a similar 3 relay board and control that with a switch. That way you have one source type, and don;t have to run the S/PDIF all over the case and through a possibly questionable rotary switch.

Or, just do the rotart switch, but definitely use S/PDIF for each. Is you use the WM8804 receiver, you get it's de-jitter feature for the USB source.

Our plan is to make another receiver based on the WM8805 to allow up to 8 S/PDIF sources.


Brian,

can i presume that 1 single avel lindberg transformer and 1 LCDPS can supply power to 2 Toslink unit, 1 sp/dif receiver, 1 darwin, 2 Opus DAC board without any problem? In this configuration - is there any easy way for the Darwin to get its 5v supply?

her shann
 
Russ White said:
Even if it is unencrypted, you would need an HDMI(1.2 or 1.3) receiver chip and supporting circuit. It is an interesting idea, and I will look into it.

Russ,

I have been doing a little research on this over the weekend. Looks like most SACD player in the market uses some sort of DSD decoder chip from Sony (CSD2750AQ). But looks like this chip is not available to the general public.

So I sent email to Wolfson and get this reply:
"That is a difficult question to answer as we don't test the WM8741 using an HDMI source. What you are looking for is along the lines of an HDMI receiver that has a DSD interface - something like AD9388? As I said, we have no experience of this chip (or other HDMI receiver chips) so can only offer it as a starting place for you to investigate."

I am not sure exactly what the AD9388 does (http://www.analog.com/en/prod/0,2877,AD9388,00.html). They asked me to sign NDA in order to get the data sheet - yikes! Sounds like this chip might not be available to the public.

Let me know if you find anything interesting.

:whazzat:
 
It's much easyer to tap the inside DAC connections after the decoding.
I have a Toshiba SD6980 SACD/DVD-A player. The DAC is a 8 channel Burr Brown (DSD1608) and there I have accesible 4 chanels of stereo PCM data and another 8 of DSD data (from the SACD chip). If I would be interested in sending those signals digitally on my receiver I would need to tap the inputs of that DAC somehow. And the receiver to have 4 (or 8) spdif inputs assignable to individual channels since I don't "know" how to mix those streams in HDMI without a HDMI transmitter (something like the AD9388 from above) or in a I2S mux stream.
PS: My SACD decoder is SAA7893HL from Phillips.
 

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