Systemic Development > Digital Audio Devices
Modems and jitter...
P.I.:
--- Quote from: GDHAL on June 07, 2023, 04:22:10 PM ---
Jitter and wow and flutter are essentially the same thing, frequency modulation.
https://en.wikipedia.org/wiki/Wow_and_flutter_measurement
or google "jitter vs wow and flutter" for other articles
--- End quote ---
Nope:
Wow and flutter are FM
Digital is timing which may or may not effect frequency response
'As for jitter, like noise, it is an undesired distortion of the signal. Jitter, however, happens in the digital realm and, rather than an unwanted variation in amplitude of an analog signal, it pertains to the timing of digital pulses. Of particular interest are the timing of the zero crossings and the timing of digital output transitions, which in turn depend on period signal crossings of decision thresholds that determine whether a bit is 1 or 0. In all cases, when there is jitter, the data stream as conveyed to the receiver will contain inaccurate information.
Like noise in general, jitter is often caused by electromagnetic interference or crosstalk. Both of these can be mitigated by identifying the sources and powering them down, or by creating greater spatial separation by rerouting wiring, by relocating equipment, or by placing shielding between source and affected data cable.
Jitter affects computer monitors, causing them to flicker, can degrade the operation of processors in computers and test instrumentation, distorts audio signals and garbles data in networks. Where possible it should be suppressed, except perhaps when used for special effects in music synthesis.
The principle types of jitter are:
• Absolute jitter, which is a measure of the deviation in time of a clock pulse edge from its ideal location.
• Period jitter, which is a variation between the ideal clock periods and actual clock periods. Synchronous circuitry as in a central processing unit is seriously impacted by these variations.
• Inter-cycle jitter, which is the difference in duration between successive clock periods. When this is excessive, microprocessors cannot function.
Jitter often but not always is characterized by a Gaussian distribution. It may be non-Gaussian when caused by a power supply or other external noise. Jitter, unfortunately, has a large presence in computer networking, where it appears as packet delay variations. Due to the disruption in timing, packets are lost, a serious problem in voice-over-IP. Service may be improved by implementing effective buffering at the receiver.'
https://www.testandmeasurementtips.com/difference-between-noise-and-jitter-faq/
http://www.sereneaudio.com/blog/what-does-jitter-sound-like#listen
GDHAL:
--- Quote from: P.I. on June 07, 2023, 04:47:34 PM ---
--- Quote from: GDHAL on June 07, 2023, 04:22:10 PM ---
Jitter and wow and flutter are essentially the same thing, frequency modulation.
https://en.wikipedia.org/wiki/Wow_and_flutter_measurement
or google "jitter vs wow and flutter" for other articles
--- End quote ---
Nope:
Wow and flutter are FM
Digital is timing which may or may not effect frequency response
'As for jitter, like noise, it is an undesired distortion of the signal. Jitter, however, happens in the digital realm and, rather than an unwanted variation in amplitude of an analog signal, it pertains to the timing of digital pulses. Of particular interest are the timing of the zero crossings and the timing of digital output transitions, which in turn depend on period signal crossings of decision thresholds that determine whether a bit is 1 or 0. In all cases, when there is jitter, the data stream as conveyed to the receiver will contain inaccurate information.
Like noise in general, jitter is often caused by electromagnetic interference or crosstalk. Both of these can be mitigated by identifying the sources and powering them down, or by creating greater spatial separation by rerouting wiring, by relocating equipment, or by placing shielding between source and affected data cable.
Jitter affects computer monitors, causing them to flicker, can degrade the operation of processors in computers and test instrumentation, distorts audio signals and garbles data in networks. Where possible it should be suppressed, except perhaps when used for special effects in music synthesis.
The principle types of jitter are:
• Absolute jitter, which is a measure of the deviation in time of a clock pulse edge from its ideal location.
• Period jitter, which is a variation between the ideal clock periods and actual clock periods. Synchronous circuitry as in a central processing unit is seriously impacted by these variations.
• Inter-cycle jitter, which is the difference in duration between successive clock periods. When this is excessive, microprocessors cannot function.
Jitter often but not always is characterized by a Gaussian distribution. It may be non-Gaussian when caused by a power supply or other external noise. Jitter, unfortunately, has a large presence in computer networking, where it appears as packet delay variations. Due to the disruption in timing, packets are lost, a serious problem in voice-over-IP. Service may be improved by implementing effective buffering at the receiver.'
https://www.testandmeasurementtips.com/difference-between-noise-and-jitter-faq/
http://www.sereneaudio.com/blog/what-does-jitter-sound-like#listen
--- End quote ---
Those are good articles you've linked to, and I appreciate you're thorough explanation. I still believe their *essentially* (of course not entirely as wow/flutter refers to analog domain and jitter the digital domain) the same for the intent and purpose of adding yet another variable into the "this sounds good or bad debate".
I'm more than happy with the results of the sound I'm hearing from my system. I've read dozens of articles about how the human ear perceives sound, which "distortion" (1st, 2nd, 3rd, etc. harmonic) sounds pleasing and which doesn't, and frankly I've forgotten 90 some odd percent of it. Easy enough to google when/if the data is needed.
Thing is, I've heard so much music in my day on so many different systems under so many different conditions, that in the end I can quote Jerry (morning dew) which is to say "I guess it doesn't matter anyway". If you feel/hear/believe it does matter, then by all means do whatever you feel is necessary to remedy the issue. At some level, even the position of the earth relative to the sun and moon at any given moment also matter, as RFI and EMI (which can contribute to jitter) varies.
I let my DAC do the "de-jittering" (my term), my ears do the listening and my brain to let me know if it sounds good (to me).
Best.
Hal
P.I.:
--- Quote from: GDHAL on June 07, 2023, 05:39:26 PM ---
--- Quote from: P.I. on June 07, 2023, 04:47:34 PM ---
--- Quote from: GDHAL on June 07, 2023, 04:22:10 PM ---
Jitter and wow and flutter are essentially the same thing, frequency modulation.
https://en.wikipedia.org/wiki/Wow_and_flutter_measurement
or google "jitter vs wow and flutter" for other articles
--- End quote ---
Nope:
Wow and flutter are FM
Digital is timing which may or may not effect frequency response
'As for jitter, like noise, it is an undesired distortion of the signal. Jitter, however, happens in the digital realm and, rather than an unwanted variation in amplitude of an analog signal, it pertains to the timing of digital pulses. Of particular interest are the timing of the zero crossings and the timing of digital output transitions, which in turn depend on period signal crossings of decision thresholds that determine whether a bit is 1 or 0. In all cases, when there is jitter, the data stream as conveyed to the receiver will contain inaccurate information.
Like noise in general, jitter is often caused by electromagnetic interference or crosstalk. Both of these can be mitigated by identifying the sources and powering them down, or by creating greater spatial separation by rerouting wiring, by relocating equipment, or by placing shielding between source and affected data cable.
Jitter affects computer monitors, causing them to flicker, can degrade the operation of processors in computers and test instrumentation, distorts audio signals and garbles data in networks. Where possible it should be suppressed, except perhaps when used for special effects in music synthesis.
The principle types of jitter are:
• Absolute jitter, which is a measure of the deviation in time of a clock pulse edge from its ideal location.
• Period jitter, which is a variation between the ideal clock periods and actual clock periods. Synchronous circuitry as in a central processing unit is seriously impacted by these variations.
• Inter-cycle jitter, which is the difference in duration between successive clock periods. When this is excessive, microprocessors cannot function.
Jitter often but not always is characterized by a Gaussian distribution. It may be non-Gaussian when caused by a power supply or other external noise. Jitter, unfortunately, has a large presence in computer networking, where it appears as packet delay variations. Due to the disruption in timing, packets are lost, a serious problem in voice-over-IP. Service may be improved by implementing effective buffering at the receiver.'
https://www.testandmeasurementtips.com/difference-between-noise-and-jitter-faq/
http://www.sereneaudio.com/blog/what-does-jitter-sound-like#listen
--- End quote ---
Those are good articles you've linked to, and I appreciate you're thorough explanation. I still believe their *essentially* (of course not entirely as wow/flutter refers to analog domain and jitter the digital domain) the same for the intent and purpose of adding yet another variable into the "this sounds good or bad debate".
I'm more than happy with the results of the sound I'm hearing from my system. I've read dozens of articles about how the human ear perceives sound, which "distortion" (1st, 2nd, 3rd, etc. harmonic) sounds pleasing and which doesn't, and frankly I've forgotten 90 some odd percent of it. Easy enough to google when/if the data is needed.
Thing is, I've heard so much music in my day on so many different systems under so many different conditions, that in the end I can quote Jerry (morning dew) which is to say "I guess it doesn't matter anyway". If you feel/hear/believe it does matter, then by all means do whatever you feel is necessary to remedy the issue. At some level, even the position of the earth relative to the sun and moon at any given moment also matter, as RFI and EMI (which can contribute to jitter) varies.
I let my DAC do the "de-jittering" (my term), my ears do the listening and my brain to let me know if it sounds good (to me).
Best.
Hal
--- End quote ---
:thumb:
Nick B:
--- Quote from: GDHAL on June 07, 2023, 05:39:26 PM ---
--- Quote from: P.I. on June 07, 2023, 04:47:34 PM ---
--- Quote from: GDHAL on June 07, 2023, 04:22:10 PM ---
Jitter and wow and flutter are essentially the same thing, frequency modulation.
https://en.wikipedia.org/wiki/Wow_and_flutter_measurement
or google "jitter vs wow and flutter" for other articles
--- End quote ---
Nope:
Wow and flutter are FM
Digital is timing which may or may not effect frequency response
'As for jitter, like noise, it is an undesired distortion of the signal. Jitter, however, happens in the digital realm and, rather than an unwanted variation in amplitude of an analog signal, it pertains to the timing of digital pulses. Of particular interest are the timing of the zero crossings and the timing of digital output transitions, which in turn depend on period signal crossings of decision thresholds that determine whether a bit is 1 or 0. In all cases, when there is jitter, the data stream as conveyed to the receiver will contain inaccurate information.
Like noise in general, jitter is often caused by electromagnetic interference or crosstalk. Both of these can be mitigated by identifying the sources and powering them down, or by creating greater spatial separation by rerouting wiring, by relocating equipment, or by placing shielding between source and affected data cable.
Jitter affects computer monitors, causing them to flicker, can degrade the operation of processors in computers and test instrumentation, distorts audio signals and garbles data in networks. Where possible it should be suppressed, except perhaps when used for special effects in music synthesis.
The principle types of jitter are:
• Absolute jitter, which is a measure of the deviation in time of a clock pulse edge from its ideal location.
• Period jitter, which is a variation between the ideal clock periods and actual clock periods. Synchronous circuitry as in a central processing unit is seriously impacted by these variations.
• Inter-cycle jitter, which is the difference in duration between successive clock periods. When this is excessive, microprocessors cannot function.
Jitter often but not always is characterized by a Gaussian distribution. It may be non-Gaussian when caused by a power supply or other external noise. Jitter, unfortunately, has a large presence in computer networking, where it appears as packet delay variations. Due to the disruption in timing, packets are lost, a serious problem in voice-over-IP. Service may be improved by implementing effective buffering at the receiver.'
https://www.testandmeasurementtips.com/difference-between-noise-and-jitter-faq/
http://www.sereneaudio.com/blog/what-does-jitter-sound-like#listen
--- End quote ---
Those are good articles you've linked to, and I appreciate you're thorough explanation. I still believe their *essentially* (of course not entirely as wow/flutter refers to analog domain and jitter the digital domain) the same for the intent and purpose of adding yet another variable into the "this sounds good or bad debate".
I'm more than happy with the results of the sound I'm hearing from my system. I've read dozens of articles about how the human ear perceives sound, which "distortion" (1st, 2nd, 3rd, etc. harmonic) sounds pleasing and which doesn't, and frankly I've forgotten 90 some odd percent of it. Easy enough to google when/if the data is needed.
Thing is, I've heard so much music in my day on so many different systems under so many different conditions, that in the end I can quote Jerry (morning dew) which is to say "I guess it doesn't matter anyway". If you feel/hear/believe it does matter, then by all means do whatever you feel is necessary to remedy the issue. At some level, even the position of the earth relative to the sun and moon at any given moment also matter, as RFI and EMI (which can contribute to jitter) varies.
I let my DAC do the "de-jittering" (my term), my ears do the listening and my brain to let me know if it sounds good (to me).
Best.
Hal
--- End quote ---
You and Dave know way more than me. All I know is the more "noise" of any type I remove from my system, the better it sounds. That includes using better cables, Dave’s great UberBUSS, the very low noise Supratek tube preamp and now using the very low jitter Holo Red streamer.
GDHAL:
--- Quote from: Nick B on June 08, 2023, 11:21:20 AM ---
You and Dave know way more than me. All I know is the more "noise" of any type I remove from my system, the better it sounds. That includes using better cables, Dave’s great UberBUSS, the very low noise Supratek tube preamp and now using the very low jitter Holo Red streamer.
--- End quote ---
Reducing "noise" is of course desirable. Fortunately, this is what good or better than good designers/companies that create audio gear are tasked with and to a large extent achieve. After you buy your gear, you can only do the common sense things like use 6 feet of speaker wire instead of 600, use power conditioning, etc. Beyond this we are all reliant on things outside of our direct control.
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