ESS Sabre Reference DAC (8-channel)

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Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
el`Ol said:
I just looked at the block diagram of the ESS Sabre and realized it does a DSD-PCM-downsampling before upsampling again. Obviously the semiconductor industry still is less fond of DSD than the music industry. What DACs are there that have true DSD (no change of sample rate)?
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Which block diagram or you referring to?

I am looking at the one in the datasheet and don't see any evidence of "downsampling".

Which document is this in?
 
Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
To me it seems more likely all the data that is clocked in (regardless of the format or rate) is internally converted into the DSP format.

The only clear differences I see are in digital filtering prior to the jitter reduction stage, but by that time the digital data is already in the DSP format.

Just curious, what was it you saw that led you to believe there was a conversion from DSD to PCM?
 
Russ White

Russ White

Member
Joined 2005
twistedpearaudio.com
el`Ol said:
What irritates me is that the DSD support is in the block that is called "oversampling filter", instead of having a parallel block, but of course a block diagram is nothing that�s scientifically exact, so maybe I was too fast in my conclusion.
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Hmm, the DSD interface is actually the first block on the digital side of things. I think what you see in the OS block is the 47,50,60,70khz DSD IIR filter modes. But all that occurs after the DATA is clocked in. Most DSD DACs do the same sort of filtering (but I suspect many not as well).

Cheers!
Russ
 
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el`Ol

Member
Joined 2005
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Spartacus

Member
Joined 2002
Well, I've been using the demo board for a few days now, and have done enough critical listening to give an early impression. Being naturally cautious, I want to live with it longer and do a little work to the demo board before being more explicit, but for now I'll say that it's capable of exceptionally transparent results. Well done ESS!
 
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dusfor99

Member
Joined 2006
el`Ol said:
I just looked at the block diagram of the ESS Sabre and realized it does a DSD-PCM-downsampling before upsampling again. Obviously the semiconductor industry still is less fond of DSD than the music industry. What DACs are there that have true DSD (no change of sample rate)?
Click to expand...


Im sorry the block diagram gave you the impress there is downsampling, However I can assure you it is not downsampled anywhere in the chain.

Thanks


Dustin
 
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dusfor99

Member
Joined 2006
el`Ol said:
What irritates me is that the DSD support is in the block that is called "oversampling filter", instead of having a parallel block, but of course a block diagram is nothing that´s scientifically exact, so maybe I was too fast in my conclusion.
Click to expand...


2 reasons for this:

1. I never planned to have DSD and PCM data at the same time, so I reused the resources in the chip for multiple purposed where I could. You could got on for a long time if this is better or not, but I will go with Occam on this one.

http://en.wikipedia.org/wiki/Occam's_Razor

2. If I drew the whole datapath out it would get very over complicated, and I also think marketting would rip it out of the documentation anyways.

Thats being said, I will galdy answer any questions on the datapath to the best of my ability....


Thanks


Dustin
 
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dusfor99

Member
Joined 2006
Russ White said:



Hmm, the DSD interface is actually the first block on the digital side of things. I think what you see in the OS block is the 47,50,60,70khz DSD IIR filter modes. But all that occurs after the DATA is clocked in. Most DSD DACs do the same sort of filtering (but I suspect many not as well).

Cheers!
Russ
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SACD requires certian filters in order to avoid the HF noise of the DSD stream from reaching your AMP's down the line, since I bet you wouldn't want to pass energy at 1Mhz or so to the front end of the amp.
 
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dusfor99

Member
Joined 2006
Spartacus said:
Well, I've been using the demo board for a few days now, and have done enough critical listening to give an early impression. Being naturally cautious, I want to live with it longer and do a little work to the demo board before being more explicit, but for now I'll say that it's capable of exceptionally transparent results. Well done ESS!
Click to expand...


Good to hear, anything that can be done to improve it is welcomed greatly. You guys should just beat up on me for all the shortcomings and ill see what I can do. Usually it will be something like this.

"Dammit, why didn't I think of that" then one of these :eek: and then ill add it to my list of "whoopies"

Thanks guys

Dustin
 
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FuriousD

Member
Joined 2004
Digital Filter in ES9008

There is very little information on the digital filter of the ES9008 in the datasheet. In fact it's not really a datasheet. The performance information looks promising.

1. Is this a real device? The lack of pin out information, absolute max spec etc suggest not quite yet.

2. Can it be bought now or is it due later?

3. What is the specification for the digital filter characteristic? Where does it roll off? 0.45Fs? 0.5Fs? 0.55Fs? What is the roll off characteristic? Can you post an FFT plot of the Digital filter output W.R.T. Fs?

4. Does it have a built in AES Receiver? + some kind of VCXO'd buffer for jitter reduction?

The information so far shows a good start, but so many of these "exciting" starts dwindle away to nothing. Can we see some more?
 
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InfiniteGain

Member
Joined 2005
Your reading the wrong threads. There are two others on the Sabre Reference DAC, (ESS ES9008). They should answer your questions.

It sounds like you only downloaded one of the available PDF files for the chip. Go to the downloads tab on the ESS website and scroll down until there is a collection of datasheet links for the chip.
 
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