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Old 2nd March 2008, 06:19 PM   #221
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Quote:
Originally posted by el`Ol
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)?

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?
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Old 2nd March 2008, 06:34 PM   #222
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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?
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Old 2nd March 2008, 06:47 PM   #223
el`Ol is offline el`Ol  Germany
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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 thatīs scientifically exact, so maybe I was too fast in my conclusion.
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Old 2nd March 2008, 06:54 PM   #224
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Quote:
Originally posted by el`Ol
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 thatïŋ―s scientifically exact, so maybe I was too fast in my conclusion.

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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Old 2nd March 2008, 07:10 PM   #225
el`Ol is offline el`Ol  Germany
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Quote:
Originally posted by Russ White

Most DSD DACs do the same sort of filtering (but I suspect many not as well).

Only very crappy DACs would pass the DSD signal without digital filtering (1 bit as it comes from the SACD), but DSD per definition works without oversampling.
BTW, any links to the patents? I didnīt read the whole thread.

edit:
I guess thatīs it:
http://v3.espacenet.com/origdoc?DB=E...73&CY=ep&LG=en
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Old 2nd March 2008, 09:14 PM   #226
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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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Old 2nd March 2008, 11:08 PM   #227
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Quote:
Originally posted by el`Ol
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)?

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.

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Old 2nd March 2008, 11:13 PM   #228
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Quote:
Originally posted by el`Ol
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 thatīs scientifically exact, so maybe I was too fast in my conclusion.

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....


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Old 2nd March 2008, 11:16 PM   #229
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Quote:
Originally posted by Russ White



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

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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Old 2nd March 2008, 11:20 PM   #230
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Quote:
Originally posted by Spartacus
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!

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 and then ill add it to my list of "whoopies"

Thanks guys

Dustin
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