Reference

Zen & The Art of D/A Conversion Page 3

It has become accepted lore in audiophile circles that the 44.1kHz sampling rate adopted for Compact Disc is too low. Some writers have argued that, as a 20kHz sinewave will only be sampled about twice per cycle, it will not be reconstructed accurately, if at all.
Thu, 09/25/1986

COMMENTS
hollowman's picture
Submitted by hollowman on April 6, 2015 - 3:48am

(Correct me as necessary...)

The "low-pass filter" in JA's above discussion is not the "oversampling digital filter" (which is, in all reality, optional) nor is it the SAME as the output low-pass filter (e.g., analog, multi-pole).

Rather, the "low-pass filter" in JA's above discussion, is a mathematical (on-paper, or theoretical) concept of digital-to-analog RECONSTRUCTION.

To put it plainly, if all you had was a bare-bones DAC chip (take one of the first-generation CD players with a chip like Philips TDA1540) -- so, no oversampling -- the above discussion of "low-pass filter", and (sin x)/x curve and impulse response would STILL apply.

I think the confusion comes from the rather liberal way the term "reconstruction filter" is used. I.e., sometimes used as an alternate to oversampling (e.g, 4x, or 8x) ... as well as the textbook terminology (as JA notes above), or here...

http://en.wikipedia.org/wiki/Reconstruction_filter

(Wiki seems to suggest that the RF can ALSO be the output analog filter, e.g., brick-wall, multi-pole, etc. AFTER the DAC chip)

Again I might stand well corrected!!

Pages

Reference

Zen & The Art of D/A Conversion Page 2

It has become accepted lore in audiophile circles that the 44.1kHz sampling rate adopted for Compact Disc is too low. Some writers have argued that, as a 20kHz sinewave will only be sampled about twice per cycle, it will not be reconstructed accurately, if at all.
Thu, 09/25/1986

COMMENTS
hollowman's picture
Submitted by hollowman on April 6, 2015 - 3:48am

(Correct me as necessary...)

The "low-pass filter" in JA's above discussion is not the "oversampling digital filter" (which is, in all reality, optional) nor is it the SAME as the output low-pass filter (e.g., analog, multi-pole).

Rather, the "low-pass filter" in JA's above discussion, is a mathematical (on-paper, or theoretical) concept of digital-to-analog RECONSTRUCTION.

To put it plainly, if all you had was a bare-bones DAC chip (take one of the first-generation CD players with a chip like Philips TDA1540) -- so, no oversampling -- the above discussion of "low-pass filter", and (sin x)/x curve and impulse response would STILL apply.

I think the confusion comes from the rather liberal way the term "reconstruction filter" is used. I.e., sometimes used as an alternate to oversampling (e.g, 4x, or 8x) ... as well as the textbook terminology (as JA notes above), or here...

http://en.wikipedia.org/wiki/Reconstruction_filter

(Wiki seems to suggest that the RF can ALSO be the output analog filter, e.g., brick-wall, multi-pole, etc. AFTER the DAC chip)

Again I might stand well corrected!!

Pages

Reference

Zen & The Art of D/A Conversion

John Atkinson  |  Sep 25, 1986

It has become accepted lore in audiophile circles that the 44.1kHz sampling rate adopted for Compact Disc is too low. Some writers have argued that, as a 20kHz sinewave will only be sampled about twice per cycle, it will not be reconstructed accurately, if at all.
Thu, 09/25/1986

As We See It

Give CD a Chance

J. Gordon Holt  |  Sep 10, 1986

According to a recent newsletter sent to its regular contributors, our "competition"—The Absolute Sound—sees "controversy and confrontation" as the core of its editorial policy. By contrast, Stereophile sees as its modus schtickus an unflagging devotion to, and pursuit of, truth, reason, all of the eternal verities (including some you never heard of), and the intelligent exchange of informed ideas. In honor of all of the above-mentioned precepts (as well as some I didn't mention), this issue of Stereophile is largely devoted to the confrontation between knowledgeable writers for whom the widely proclaimed perfection of the Compact Disc remains a controversial issue.
Wed, 09/10/1986

Think Pieces

Legitimate Dealers Speak Out! Page 2

In his April 16, 2001 website essay "Where's Our Freedom of Audio Choice?" reader Jim Tavegia railed against the ubiquitous policy of manufacturers only allowing their products to be available through selected retailers. "If I'm willing to pay the UPS costs, it should be my prerogative to buy equipment anywhere I please," he wrote. This echoes a controversy that appeared in the print magazine 15 years ago. The affair started with some innocent-looking text written by Audio Cheapskate Sam Tellig in the December 1985 Stereophile (Vol.8 No.8):
Sat, 03/01/1986

Think Pieces

Legitimate Dealers Speak Out!

Evelyn & Neil Sinclair  |  Mar 1, 1986

In his April 16, 2001 website essay "Where's Our Freedom of Audio Choice?" reader Jim Tavegia railed against the ubiquitous policy of manufacturers only allowing their products to be available through selected retailers. "If I'm willing to pay the UPS costs, it should be my prerogative to buy equipment anywhere I please," he wrote. This echoes a controversy that appeared in the print magazine 15 years ago. The affair started with some innocent-looking text written by Audio Cheapskate Sam Tellig in the December 1985 Stereophile (Vol.8 No.8):
Sat, 03/01/1986

As We See It

Stop Digital Madness! LA Appends

The title of this month's column is the legend Sheffield Labs emblazoned on a T-shirt a couple of years ago, to promote their jaundiced view of digital audio. Since then, even Sheffield's reactionary perfectionists softpedalled their anti-digital crusade, perhaps because of the number of CDs they've been selling! Their personnel no longer wear those T-shirts at CES, which is unfortunate. Although most people in the audio field no longer see digital audio as madness, digital denouncing is still very much with us.
Tue, 12/03/1985

As We See It

Stop Digital Madness! JGH Responds

The title of this month's column is the legend Sheffield Labs emblazoned on a T-shirt a couple of years ago, to promote their jaundiced view of digital audio. Since then, even Sheffield's reactionary perfectionists softpedalled their anti-digital crusade, perhaps because of the number of CDs they've been selling! Their personnel no longer wear those T-shirts at CES, which is unfortunate. Although most people in the audio field no longer see digital audio as madness, digital denouncing is still very much with us.
Tue, 12/03/1985

As We See It

Stop Digital Madness! Professor Reilly responds part 2

The title of this month's column is the legend Sheffield Labs emblazoned on a T-shirt a couple of years ago, to promote their jaundiced view of digital audio. Since then, even Sheffield's reactionary perfectionists softpedalled their anti-digital crusade, perhaps because of the number of CDs they've been selling! Their personnel no longer wear those T-shirts at CES, which is unfortunate. Although most people in the audio field no longer see digital audio as madness, digital denouncing is still very much with us.
Tue, 12/03/1985

As We See It

Stop Digital Madness! Professor Reilly responds

The title of this month's column is the legend Sheffield Labs emblazoned on a T-shirt a couple of years ago, to promote their jaundiced view of digital audio. Since then, even Sheffield's reactionary perfectionists softpedalled their anti-digital crusade, perhaps because of the number of CDs they've been selling! Their personnel no longer wear those T-shirts at CES, which is unfortunate. Although most people in the audio field no longer see digital audio as madness, digital denouncing is still very much with us.
Tue, 12/03/1985

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