ESS Sabre Reference DAC (8-channel)

[Russ White]

DSD5 to DSD1
DSD6 to DSD4 to DSD2.

Dustin, I know it connected internally, but would it hurt to also tie DSD3 to DSD1? Or do I need to leave it floating?

 

[rossl]

Oh I certainly agree it probably not worth bothering with!

That said, I actually do have several older CDs that do have pre-emphasis. But I rarely play them.

It just seemed like a natural thing to do.

You would be amazed how many emails I get asking about it.

Cheers!
Russ

Doesn't the CD player handle it, anyway?

Since we are using Oppos and Denons as transports and picking the data off just before their DAC chips, the controller should have recognized that de-emphasis is needed and apply the DSP.

Right?

 

[Dougie085]

Well not everyone is going to use it with a CDP like that. Everyone has their own setup scheme and they want the DAC's to be as versatile as possible.

 

[Russ White]

Doesn't the CD player handle it, anyway?

Since we are using Oppos and Denons as transports and picking the data off just before their DAC chips, the controller should have recognized that de-emphasis is needed and apply the DSP.

Right?

How can you assume what CDP a person is using with the DAC? I have folks using my DACs with all sorts of transports, most (all that I know of even my Denons) leave the PCM intact (straight from the Disc) through SPDIF.

If you have a CS8416 or Wm8804 watch the deemph flag, some very old CDs will light it up.

Cheers!
Russ

 

[Russ White]

One note, I actually don't even see any register to check for detecting pre-emphasis when using SPDIF input.... This seems a little odd to me unless it is handled automatically.

 

[rossl]

In that case you will need a SPDIF receiver (Wolfson, CS, etc.) to check the de-emp flag, and the microcontroller will have to watch the flag and set the register in the Sabre8.

 

[Russ White]

In that case you will need a SPDIF receiver (Wolfson, CS, etc.) to check the de-emp flag, and the microcontroller will have to watch the flag and set the register in the Sabre8.

Yes, I knew I could do that, but I figured that since they implemented a SPDIF receiver they may also check the flags present on the SPDIF signal.

I hope Dustin chimes in on this as I wonder if its tucked away in there some place.

 

[jargon]

Better late than never....

I expect to have in the sunny UK by mid March :-

http://www.esstech.com/products/digitalaudio/digitalaudio.shtm
(ES9008) parts samples

///////////
It would be nice to see these chips on PCBs across the UK before summer.

 

[Russ White]

Updated/Corrected schematic

Ok, assuming that its ok to connect DSD1 and DSD3 I am using Dustin's recommendation for supporting 3 signal input and PCM/DSD/SPDIF inputs.

I am using a small PIC12F629 just to do basic configuration like PCM format etc, as well as change the automute setting (thanks Ross!).

More complex control can be added via a separate PCB, and you can simply omit the PIC if you like as it will be socketed.

I am a bit curious about the comparator bit at the SPDIF input. I have never used such a circuit. Does that part look ok? I basically copied that piece from the eval board schematic.

Thanks for the great input so far.

Cheers!
Russ

 

[Russ White]

top(preliminary)

 

[Russ White]

bottom(preliminary)

 

[Russ White]

Notice in the new layout the analog output GND traces run directly to their respective AGND pins on the bottom side.

 

[dusfor99]

The Oppo players are worth considering..
And very very cheap..

Tried that, but there DSD signal is not anywhere on the PCB. Basically, the DSD is converted to PCM before being sent to the DAC

Dustin

 

[dusfor99]

Re: Re: Re: PCB top (preliminary)

Dustin, would you recommend against doing I/V on a seperate board connected via wires then?

Dan

I have only done signle boards myself, I think the answer will lie in Russ's board. The PCB looks clean, so it may be no issue. (I hope)


Dustin

 

[dusfor99]

Dustin, I know it connected internally, but would it hurt to also tie DSD3 to DSD1? Or do I need to leave it floating?

10k to ground.

 

[dusfor99]

Yes, I knew I could do that, but I figured that since they implemented a SPDIF receiver they may also check the flags present on the SPDIF signal.

I hope Dustin chimes in on this as I wonder if its tucked away in there some place.

The de-emphasis flag is not detected by the SPDIF reciever in this rev of the chip. Yes, its obvious it should have been, but it was overlooked . Once again, sorry guys.

Dustin

 

[Russ White]

10k to ground.

Ok So does that mean I can't just tie DSD1 to DSD3? It must be 10K to GND?

 

[rossl]

The Oppo players are worth considering..
And very very cheap..

Tried that, but there DSD signal is not anywhere on the PCB. Basically, the DSD is converted to PCM before being sent to the DAC

Dustin

That's why I like the Oppo

It converts the DSD to PCM so I can use a DSP equalizer to correct for speakers and room reflections before sending it to the DAC.

Correcting the bass for the room standing waves and zeros makes it sound awesome.

 

[Dougie085]

But then that bypasses the DSD support of the DAC. And if you want to do that you can just feed the DAC SPDIF or something.

 

[Russ White]

Lots of pro gear uses DSD, thats why I have decided to make the feature available.

I also actually want take DSD from my Denon players.