Highest resolution without quantization noise

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...100 ms latency is an imperfection as well...

In what way should an latency of 100ms. (so long as it's constant delay versus frequency) be considered an imperfection for the purpose of home playback? Before you answer, keep in mind that an CD (or an vinyl album for that matter) could easily have an playback latency measured in tens of years with respect to the original recorded event. Causality demands that any recorded event must exhibit latency upon playback, so I'm not sure where you've come by the notion that this counts as an in perfection. Editing, and lip synching for video requirements are a different matter than for audio only home playback
 
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Kastor L said:
Perfection, is when it is as if no sampling is taking place at all.
I think your idea of perfection requires infinite bandwidth. In the real world that is not possible, as it would require infinite power to run the circuits. Given the more realistic aim of reproduction of a band-limited signal then sufficiently fast sampling with a good reconstruction filter can achieve it.

Why do people often demand of digital audio things they would never demand of analogue audio: infinite bandwidth, zero distortion, zero noise (so needing cryogenic circuitry) and acausality (so requiring a time machine)? It is obviously daft to require these things of analogue; it happens to be equally daft (but perhaps less obvious) to require these things of digital.
 
I think your idea of perfection requires infinite bandwidth. In the real world that is not possible, as it would require infinite power to run the circuits. Given the more realistic aim of reproduction of a band-limited signal then sufficiently fast sampling with a good reconstruction filter can achieve it.

Why do people often demand of digital audio things they would never demand of analogue audio: infinite bandwidth, zero distortion, zero noise (so needing cryogenic circuitry) and acausality (so requiring a time machine)? It is obviously daft to require these things of analogue; it happens to be equally daft (but perhaps less obvious) to require these things of digital.

Can be "on paper" digital is more perfect than analog.
 
If only the reccording devices & process could have the same paranoia level of "perfection" we are looking for here !

We are limited by the equipments than each Studio has like the talent of the sound "engineer" for the reccording capture & mix for making a disc ! Everybody is not Chesky !

We spend a lot of time to make sounding better the limitations before without changing this lasts on the reccording side !

Simple thought... maybe false !
 
Recorded with analog tape or a digital box?

Setting aside the level of transparency of the microphone and the ADC, I was referring to the IR after the ADC, if we can zoom in on it and see all of it precisely.

Here is some text on microphones and ADC I saw today — The Fifth Element #78 Page 2 | Stereophile.com

In a video chat with Cypress's first violinist, Cecily Ward, I asked how they came to record with such exotic microphones, and at Skywalker, no less.

Indeed, the Cypress was so taken with the sound of the Sanken CO-100K's that they bought their own matched pair.

Do you have thoughts on how an impulse response looks in analog cassette tape? Your question seems a bit loaded I'm not sure.

______

that perfect reproduction is only possible if the waveform which is sampled contains no frequency components higher than the Nyquist frequency ///

No, that doesn't seem true at all. Perhaps you need to reclarify.

See text here — dsd

Comparing DSD to PCM, what stands out is the Nyquist frequency (the highest frequency that can be modulated) is a remarkable 1.4MHz, in video territory.

The Nyquist frequencies for PCM are much lower:

22.05kHz for Red Book CD's

48kHz for 96/24

96kHz for 192/24

176.4kHz for 352.8/24 DXD.

It's clear DSD is optimized for time response, with near-video impulse response, and does not require the brickwall filters of the slower PCM formats.

For one thing, it's nearly impossible to see less than 2% distortion on a scope, and 2% distortion is audible to nearly any listener.
This as well — http://www.cirrus.com/en/pubs/whitePaper/DS668WP1.pdf

Figure 2 shows the impulse response of the same

filter at a 96 kHz sample rate. It is apparent that the pre-echo has shorter time duration and less time dispersion
than at 48 kHz.
As a result of this, many industry experts have suggested that the
additional bandwidth offered by the higher sample rates be used as a transition band to allow the use of
less aggressive digital filtering, which minimizes pre-echoes and time dispersion even further. Julian
Dunn [4] and Mike Story [7] have both written very nice discussions of this subject.

///

Tom Holman reports [10] that in his laboratory environment at
the University of Southern California that is dominated by direct sound, a channel-to-channel time offset
equal to one sample period at 48 kHz is audible. This equates to 20
μsec of inter-channel phase distortion

across the entire audio band. Holman [10] also mentions, “one just noticeable difference in image shift
between left and right ear inputs is 10
μsec”.
Plus this — http://www.audio-trek.net/diyAudio/MinPhaseIntro/MinimumPhase.htm

Impulse_Responses.GIF


______

Now, you're worried about pre-ringing on waveforms with sharp corners or steps like a squarewave, any such waveform has frequency components out to infinity ///

I'm concerned about pre-ringing in all sines, not only in perfect square-waves or in ultrasonic sines.

This isn't an ultrasonic discussion the way you paint it.


/// If the output waveform looks like a step, but with pre-ringing (and post-ringing), then

A) The original input signal had pre-ringing and post-ringing, and the output is a perfect reprodution of it.

Reality is always minimum-phase, unless you're recording a recording or you're recording an unusual speaker which has linear-phase events in it or similar unusual events like that.

B) The original input signal had frequency components above the Nyquist limit, and it's therefore impossible to reproduce it accurately.

You seem to be confused, really.

A maximum-phase filter, is always pre-ringing with no post-ringing.

What does the pre-ringing, in that case, have in connection to Nyquist or ultrasonics?
 
Setting aside the level of transparency of the microphone and the ADC, I was referring to the IR after the ADC, if we can zoom in on it and see all of it precisely.

In that case its the impulse of the AAF you'll be seeing. Most ADCs these days are S-D architecture meaning the effective AAF (due to high oversampling ratios) is a linear phase FIR filter.

Do you have thoughts on how an impulse response looks in analog cassette tape? Your question seems a bit loaded I'm not sure.

I was referring to R2R tape, not cassette. No idea, no.
 
In what way should an latency of 100ms. (so long as it's constant delay versus frequency) be considered an imperfection for the purpose of home playback? Before you answer, keep in mind that an CD (or an vinyl album for that matter) could easily have an playback latency measured in tens of years with respect to the original recorded event. Causality demands that any recorded event must exhibit latency upon playback, so I'm not sure where you've come by the notion that this counts as an in perfection. Editing, and lip synching for video requirements are a different matter than for audio only home playback

When I think of latency, I usually think of connecting a Midi synthesizer or an electric guitar to a computer.

If you hit a key on the keyboard, you want it to make a sound when you hit the key, not 100ms later.

That's why ASIO or KS is paramount in some areas, but it certainly can't fix the error in a reconstruction filter.

ASIO is needed in some PC games as well.

After that, we have audio/visual, like watching fast action sports, you want the physical action to connect with the sound, then it looks much more real.

For "audio only" playback I don't suspect it causes very much imperfection.

The only area I can think of would be the hardware or software code, or the hardware components, causing the imperfection in that case.

For example quite a few people say media players, i.e. software code and ASIO or KS sound different.

In the case of KS that would be due to the "direct stream" of the data without buffering. It becomes a "straight river" of data instead of a "complicated aqueduct", but this is the area when audio starts to become far-fetched in how electron transmission affects the sound-quality.


Can be "on paper" digital is more perfect than analog.

You mean digital is more perfect than reality, or more perfect than vinyl and tape?


If only the reccording devices & process could have the same paranoia level of "perfection" we are looking for here !

That is why DSD usually sounds better than CD's, the studios which use DSD are "paranoid" and use better microphones and ADC as well.

Remember that "garagerock" received it's name from being recorded in a garage.....

Most likely with not very good recording equipment......

Yet it still sounds pretty good imho, LoL.
 
I think your idea of perfection requires infinite bandwidth. In the real world that is not possible, as it would require infinite power to run the circuits. Given the more realistic aim of reproduction of a band-limited signal then sufficiently fast sampling with a good reconstruction filter can achieve it.

Why do people often demand of digital audio things they would never demand of analogue audio: infinite bandwidth, zero distortion, zero noise (so needing cryogenic circuitry) and acausality (so requiring a time machine)? It is obviously daft to require these things of analogue; it happens to be equally daft (but perhaps less obvious) to require these things of digital.

In the extreme, perfect sense of perfection, then yes.

I only have a basic Sony pocket recorder, I don't record, but if I did then I would consider DSD or DSD-Wide with an Audio-Technica AT-8015 microphone.

With playback I'm inclined to believe we need video-like transient response to achieve a more surreal sound.

For example one of the best sounding DAC's I have ever heard was using an AD828 video chip.
 
This article is amazing — dsd

/// DSD, and to a lesser degree delta-sigma PCM, have a different ultrasonic spectra than ladder-converter PCM.

All three classes of converter generate ultrasonic spectra, but are quite different in content.

Ladder converters create narrow spectral lines that track program content, while DSD creates broadband noise in the 1MHz region.

The most widely used opamps, like the 5532/5534 and 797, have very poor linearity in the MHz region.

Audio opamps are not video amplifiers; the feedback is almost gone at these frequencies, Class AB switching is much more prominent, and slewing (intervals of 100% distortion; input and output no longer correlate) can easily occur.

How easily? Well, to reproduce that 20MHz comb spectra requires a device with a slew rate of 1000V/uSec. The 5532/5534 has a slew rate of 13V/uSec, the 797 a slew rate of 20V/uSec, and many other audiophile favorites are no higher than 50V/uSec. If the designer chooses to use active current-to-voltage conversion with an opamp (a transimpedance amplifier), the opamp will be exposed to transitions that are 1000V/uSec or faster.

If the designer chooses to use an active lowpass filter, such as the popular Sallen & Key circuit, the active filter has increased distortion at the corner frequency, thanks to positive feedback. In other words, the filter gets in trouble at the same frequencies it is meant to remove!

Unfortunately, the most popular analog architecture in high-end DACs is just what I've described; active current-to-voltage converters using low-speed opamps (selected for ultra-low noise and very low THD at audio frequencies), followed by the active filtering using a similar type of opamp. The MHz frequencies that are causing all of the trouble don't disappear until the output of the active lowpass filter.

What happens when the MHz output of the converter crossmodulates with audio at much lower frequencies? Distortion – folded down to the audio band. Opamp distortion from 1MHz to 10MHz range can be expected to fall in the 0.1% to 3% range, as a result of 60dB less feedback (compared to 1kHz). See the following paper by Fiori and Crovetti, published in the IEEE Transactions on Circuits and Systems:

http://www.uemc.polito.it/papers/opampsusc_01.pdf

In the interest of power efficiency, opamps usually have Class AB output stages; this is not a problem at audio frequencies, thanks to very high feedback ratios, but at a MHz or more, with feedback mostly gone, a Class AB opamp will have poorly controlled Class AB transitions. A device that is well-behaved at 1kHz is not as well-behaved when operated at a frequency a thousand to ten thousand times higher.

If the MHz content from the converter is white noise, the baseband audio spectra will be thickened by close-in IM distortion. Narrow spectral lines will have phase noise added, making the spectrum denser.

This might not sound too bad; what made the Yamaha DX7 synthesizer "The Sound of the Eighties" was FM modulation of the synthesizer tones. FM modulation, of the right kind, adds a thickness and density to the sound. Thin-sounding musical sources might actually sound a bit more "filled-out", but full symphonic or choral music could turn into a roar of distortion.

The narrow spectral lines of the ladder/R-2R converters would sound quite different; there would be non-harmonically related IM tones moving through the audio band; the nature of these tones would depend on just how badly the opamps handled the MHz region.

As long as low-speed analog circuits are exposed to RF frequencies, the audio band will be filled with distortion artifacts that have an extremely complex relation to the input signal. Once slewing and cross-modulation from RF interference happens, no amount of clean-up after the fact can correct it.

The character of the distortion artifacts will be different for ladder converters, delta-sigma converters, and DSD converters. Which takes us to the next section—how do we measure what's coming out to the converter?

Measuring Ultrasonic Content

How much ultrasonic content does a converter generate when fed a 20kHz full-modulation tone? The Burr-Brown PCM-63 ladder converter generates a "comb spectra" that is flat out to 20MHz and declines into the noise floor at 50MHz. (It's real. I saw this for myself on the HP spectrum analyzer screen.) How is this measured accurately?

The ultrasonic content from the RCA or XLR of DAC audio component is not of interest; you want to see what is coming directly from the converter chip itself. The circuit board trace that goes to the current-output pin of the DAC chip can be temporarily soldered to the center conductor of a 50-ohm coax cable that goes directly to an RF spectrum analyzer (the cable shield is soldered to the trace going to the analog ground of the DAC chip).

The analyzer needs to have 100MHz bandwidth, and an on-screen dynamic range of at least 80dB, preferably more. The Philips TDA 154x series of DACs, and the TI/Burr-Brown PCM-63, 1702, and 1704 DACs work correctly with a 50-ohm termination, which is provided by the RF spectrum analyser.
 
Claiming that the thickening of spectral lines from DSD IM is an advantage seems like making a virtue of necessity. It also seems to be confusing the basic issues of a technique with the typical implementation problems of a technique.

Claiming that misuse of opamps in DAC circuitry (e.g. as I/V converters, or active filters) is somehow a fundamental flaw in DACs is missing the point. Passive pre-filtering can slow the signal seen by the opamp down to the region where the opamp is well behaved.

This thread now appears to be casting around for a new purpose, given that the original question was meaningless. It is fast heading for the usual Fourier/Shannon/Nyquist/causality denial paradigm.
 
The original question was pertaining to amplitude resolution and time resolution.

Without any kind of noise floor at all then the bit depth is either infinite or it varies from silence to the loudest sound possible.

However the dynamic range of the music itself will only vary 96 dB with 16-bit / 44.1 kHz music.

With oversampling you can achieve the equivalent of 17-bit resolution or 102 dB.

However that is only the dynamic range to the quantization noise floor, it's still 96 dB even though it's stated as 102 dB.

Apparently with shaped dither you can achieve 120 dB dynamic range with 16-bit audio, however it's still 96 dB at the same time.

There are multiple "dynamic ranges" for a single bit-depth, at the same time, sources like Wikipedia and everywhere else I checked make zero distinction for this.

We can also avoid quantization error and dither entirely by simply making a 16-bit file via software alone, like in Reason, what is the dynamic range then?

No distinction for that either.

You can call the question whatever you want, it seems more like you're utilitarian and quick to dismiss all non-textbook discussion.
 
Apparently with shaped dither you can achieve 120 dB dynamic range with 16-bit audio, however it's still 96 dB at the same time.

Ah that's not engineering dynamic range, that's perceptual dynamic range. Easy to confuse the two but they're not equivalent - with shaped dither the engineering (measured) dynamic range will actually be lower than 96dB by quite a bit seeing as the shaping can only move noise around (within the 22kHz bandwidth) it can't remove it. The shaped dither gets its increased perceived dynamic range by moving noise away from the 2-4kHz band where the ear is most sensitive and piling it up at higher freqs (where the ear isn't so sensitive).
 
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