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ESS claim DAC pushes the boundaries of audio science, They claim results are supported by blind testing
wakibaki
post Jan 23 2013, 04:23
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Apologies if this topic has been posted previously, I did a search but found nothing.

http://www.youtube.com/watch?feature=playe...p;v=1CkyrDIGzOE

The above link shows a youtube video of an ESS presentation at RMAF.

Granted it is a sales presentation, it details advances ESS claim in the design of their sigma-delta DACs.

Foremost in the claims is the fact that some people can evidently hear features well below the noise floor which were previously held by the majority of engineers to be inaudible. This is said to be confirmed in blind testing.

Large changes in the values of variables in the state space are said to contribute to non-periodic steady-state noise normally invisible using conventional measurement techniques. This is visible when instrumentation is used to examine the Noise-vs-DC Offset.

This is said to be minimized in ESS products by techniques designed to control the state-space related noise by rapidly quenching state variable excursions.

ESS also claim that a further artifact of sigma-delta modulators, variable (non-linear) excess phase, which causes oscillation in S-D modulators, has been eliminated by making their devices unconditionally stable, and that this too contributes to greater acceptance of the devices by some listeners, although the reasons for this are apparently not clearly understood.

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Dynamic
post Jan 23 2013, 21:13
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I think inter-aural timing differences under 1ms can be audible, but that shouldn't be exposed by jitter thanks to phase locked loop clock recovery or equivalent (which runs at the baud rate, itself much higher than the sample rate - typically 6MHz or so for S/PDIF). The thing is, jitter of 1 ms would be 6000 cycles on a 6MHz clock. That's ludicrously high jitter. A fair bit less that 1ms still remains ludicrously high.

16-bit, 44.1 kHz PCM can easily encode timing differences below even the sampling period, as you can prove by making a large pulse at some point in both channels in an otherwise silent 192kHz stereo track, then select one channel and insert one sample silence to shift it by about 5.2 microseconds. Then downsample to 44.1 kHz and upsample back to 192 kHz and see that the timing difference is preserved. (Same sort of thing works in photo editing to correct for colour misalignment in scanned printed materials even when it's below one pixel-width of misalignment, as long as you upsample and downsample with proper respect for Nyquist and Shannon)

Dropped or repeated samples might also be audible if you fail to synchronise clocks and thus mess up the PCM signal.
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Posts in this topic
- wakibaki   ESS claim DAC pushes the boundaries of audio science   Jan 23 2013, 04:23
- - saratoga   DACs were a solved problem ten years ago so I...   Jan 23 2013, 05:28
- - phofman   The claim would have been much more credible if th...   Jan 23 2013, 08:13
|- - wakibaki   QUOTE (phofman @ Jan 23 2013, 07:13) The ...   Jan 23 2013, 18:36
- - pdq   I haven't watched the video, but if the DBT th...   Jan 23 2013, 18:54
|- - Dynamic   pdq, it wasn't all about hearing below -96 dB ...   Jan 23 2013, 20:10
- - Dynamic   There's some plausible stuff in there, but the...   Jan 23 2013, 19:22
- - Willakan   During the presentation on jitter, the ESS guy als...   Jan 23 2013, 20:40
|- - Banned   QUOTE (Willakan @ Jan 23 2013, 21:40) Dur...   Jan 23 2013, 21:01
- - wakibaki   One of the 'golden ear' claims that has be...   Jan 23 2013, 21:04
|- - db1989   QUOTE (wakibaki @ Jan 23 2013, 20:04) Ult...   Jan 23 2013, 21:25
|- - Dynamic   QUOTE (wakibaki @ Jan 23 2013, 20:04) Ult...   Jan 23 2013, 21:49
|- - Arnold B. Krueger   QUOTE (wakibaki @ Jan 23 2013, 15:04) ESS...   Jan 24 2013, 14:12
- - Dynamic   I think inter-aural timing differences under 1ms c...   Jan 23 2013, 21:13
- - greynol   Until positive DBT results can be repeated by an i...   Jan 23 2013, 21:38
|- - wakibaki   QUOTE (greynol @ Jan 23 2013, 20:38) Unti...   Jan 23 2013, 23:14
|- - greynol   QUOTE (wakibaki @ Jan 23 2013, 14:14) If ...   Jan 23 2013, 23:25
||- - wakibaki   QUOTE (greynol @ Jan 23 2013, 22:25) Fall...   Jan 24 2013, 02:09
||- - pdq   QUOTE (wakibaki @ Jan 23 2013, 20:09) No,...   Jan 24 2013, 03:06
||- - Nessuno   QUOTE (pdq @ Jan 24 2013, 03:06) Last I k...   Jan 24 2013, 18:00
|- - saratoga   QUOTE (wakibaki @ Jan 23 2013, 17:14) If ...   Jan 24 2013, 02:56
- - Willakan   Pretty impressive typo in my earlier post: I meant...   Jan 23 2013, 22:36
- - greynol   Funny how it is you who gets to rely on words like...   Jan 24 2013, 02:46
- - greynol   ...until it is disproved that the Flying Spaghetti...   Jan 24 2013, 03:06
- - Arnold B. Krueger   QUOTE (wakibaki @ Jan 22 2013, 22:23) Apo...   Jan 24 2013, 14:28
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jan 24 2013, 13...   Jan 24 2013, 18:50
|- - dhromed   QUOTE (2Bdecided @ Jan 24 2013, 18:50) so...   Jan 25 2013, 11:50
||- - 2Bdecided   QUOTE (dhromed @ Jan 25 2013, 10:50) I...   Jan 25 2013, 13:56
||- - 2Bdecided   QUOTE (2Bdecided @ Jan 25 2013, 12:56) I ...   Jan 25 2013, 17:59
|||- - Arnold B. Krueger   QUOTE (2Bdecided @ Jan 25 2013, 11:59) QU...   Jan 25 2013, 19:28
|||- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jan 25 2013, 18...   Jan 25 2013, 19:49
||- - dhromed   QUOTE (2Bdecided @ Jan 25 2013, 13:56) QU...   Jan 26 2013, 00:19
|- - Arnold B. Krueger   QUOTE (2Bdecided @ Jan 24 2013, 12:50) QU...   Jan 25 2013, 13:15
|- - 2Bdecided   QUOTE (Arnold B. Krueger @ Jan 25 2013, 12...   Jan 25 2013, 13:53
|- - Arnold B. Krueger   QUOTE (2Bdecided @ Jan 25 2013, 07:53) QU...   Jan 25 2013, 16:35
|- - benski   QUOTE (Arnold B. Krueger @ Jan 25 2013, 11...   Jan 25 2013, 17:24
|- - 2Bdecided   QUOTE (benski @ Jan 25 2013, 16:24) What ...   Jan 25 2013, 17:55
||- - benski   QUOTE (2Bdecided @ Jan 25 2013, 12:55) an...   Jan 25 2013, 18:22
||- - Arnold B. Krueger   QUOTE (benski @ Jan 25 2013, 12:22) QUOTE...   Jan 25 2013, 18:27
||- - 2Bdecided   QUOTE (benski @ Jan 25 2013, 17:22) QUOTE...   Jan 25 2013, 19:44
|- - Arnold B. Krueger   QUOTE (benski @ Jan 25 2013, 11:24) QUOTE...   Jan 25 2013, 18:21
- - Willakan   There's certainly no shortage of contentious c...   Jan 24 2013, 22:28
|- - Hotsoup   QUOTE (Willakan @ Jan 24 2013, 14:28) ......   Jan 24 2013, 22:46
- - 2Bdecided   This one is quite interesting... http://www.youtub...   Jan 25 2013, 11:12
- - Woodinville   Digital will not sound like analog until we start ...   Jan 25 2013, 11:13
- - db1989   If he hasnít had his lunch yet, his blood glucose ...   Jan 25 2013, 18:30
- - 2Bdecided   QUOTE (db1989 @ Jan 25 2013, 17:30) If he...   Jan 25 2013, 19:51


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