Author Topic: Modems and jitter...  (Read 3199 times)

Offline P.I.

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Modems and jitter...
« on: June 06, 2023, 11:36:02 AM »
"A man with an experience is never at the mercy of a man with an argument." - Hilmar von Campe

Offline GDHAL

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Re: Modems and jitter...
« Reply #1 on: June 06, 2023, 11:48:36 AM »
Interesting thread at What's Best:

https://www.whatsbestforum.com/threads/cable-modems.30094/

The article reads as though it's specific to routers and modems. In any case, I rely on my DAC reclocker and my own ears. I'm not particularly worried about jitter. No playback system is exactly perfect, analog (with wow and flutter) or digital (with jitter as the analog equivalent).

Best.

Hal
GoldenEar Triton Reference (pair), Musical Fidelity M6si, Schiit Yggdrasil-OG-B, Oppo UDP-205, Emotiva ERC-3, LG OLED65C9PUA, Salamander Synergy Triple Unit SL20, Audeze LCD-X, GIK acoustic paneling
http://halr.x10.mx/other.html

Offline Nick B

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Re: Modems and jitter...
« Reply #2 on: June 07, 2023, 12:27:14 PM »
Interesting topic, Dave, and very applicable to my current situation. After many weeks of waiting and constantly pushing my internet provider, they finally were able to run  RG11 from the street to my house. It'll be 3 more weeks until they actually hook me up in the house, but hey, i'll take it. Jack has suggested a whole house mesh system and an Arris router with DOCSIS 3.1 and that's what i bought and is awaiting installation. I believe my unit is an Arris SB 6600. It uses a 12v power supply. The mesh units are TP Link.

The first thing that occurred to me is trying to use one of my 2 lps for the Arris rather than the wall wart. One lps is from Mojo Audio  in New Mexico. It is 15v and I am wondering if it can be modded/adjusted down to 12v.

Hal made a comment as to jitter. I had the good fortune to buy a used Holo Audio Red streamer which supposedly has the lowest jitter as to streamers. I will say that the performance boost over my excellent iFi Zen streamer is significant. Whether it is because of the lower jitter, I can't say, but it's interesting to note. The iFi was using the Mojo Audio lps as it's power supply.
Orchard Starkrimson Ultra amp
Supratek Chardonnay preamp
JMR Voce Grande speakers
Border Patrol SEi dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline P.I.

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Re: Modems and jitter...
« Reply #3 on: June 07, 2023, 03:55:12 PM »
Interesting topic, Dave, and very applicable to my current situation. After many weeks of waiting and constantly pushing my internet provider, they finally were able to run  RG11 from the street to my house. It'll be 3 more weeks until they actually hook me up in the house, but hey, i'll take it. Jack has suggested a whole house mesh system and an Arris router with DOCSIS 3.1 and that's what i bought and is awaiting installation. I believe my unit is an Arris SB 6600. It uses a 12v power supply. The mesh units are TP Link.

The first thing that occurred to me is trying to use one of my 2 lps for the Arris rather than the wall wart. One lps is from Mojo Audio  in New Mexico. It is 15v and I am wondering if it can be modded/adjusted down to 12v.

Hal made a comment as to jitter. I had the good fortune to buy a used Holo Audio Red streamer which supposedly has the lowest jitter as to streamers. I will say that the performance boost over my excellent iFi Zen streamer is significant. Whether it is because of the lower jitter, I can't say, but it's interesting to note. The iFi was using the Mojo Audio lps as it's power supply.

Jitter and wow and flutter are not really equivalent.  W&F result in pitch wandering whereas jitter is more of a noise, rise time and aliasing bug.

I'm sure Ben can reconfigure his LPS for you.

Good luck getting anything don in a timely manner...  my secret cynic is pissed off right now! 😡 
"A man with an experience is never at the mercy of a man with an argument." - Hilmar von Campe

Offline GDHAL

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Re: Modems and jitter...
« Reply #4 on: June 07, 2023, 04:22:10 PM »
Interesting topic, Dave, and very applicable to my current situation. After many weeks of waiting and constantly pushing my internet provider, they finally were able to run  RG11 from the street to my house. It'll be 3 more weeks until they actually hook me up in the house, but hey, i'll take it. Jack has suggested a whole house mesh system and an Arris router with DOCSIS 3.1 and that's what i bought and is awaiting installation. I believe my unit is an Arris SB 6600. It uses a 12v power supply. The mesh units are TP Link.

The first thing that occurred to me is trying to use one of my 2 lps for the Arris rather than the wall wart. One lps is from Mojo Audio  in New Mexico. It is 15v and I am wondering if it can be modded/adjusted down to 12v.

Hal made a comment as to jitter. I had the good fortune to buy a used Holo Audio Red streamer which supposedly has the lowest jitter as to streamers. I will say that the performance boost over my excellent iFi Zen streamer is significant. Whether it is because of the lower jitter, I can't say, but it's interesting to note. The iFi was using the Mojo Audio lps as it's power supply.

Jitter and wow and flutter are not really equivalent.  W&F result in pitch wandering whereas jitter is more of a noise, rise time and aliasing bug.

I'm sure Ben can reconfigure his LPS for you.

Good luck getting anything don in a timely manner...  my secret cynic is pissed off right now! 😡

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
GoldenEar Triton Reference (pair), Musical Fidelity M6si, Schiit Yggdrasil-OG-B, Oppo UDP-205, Emotiva ERC-3, LG OLED65C9PUA, Salamander Synergy Triple Unit SL20, Audeze LCD-X, GIK acoustic paneling
http://halr.x10.mx/other.html

Offline P.I.

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Re: Modems and jitter...
« Reply #5 on: June 07, 2023, 04:47:34 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
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
"A man with an experience is never at the mercy of a man with an argument." - Hilmar von Campe

Offline GDHAL

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Re: Modems and jitter...
« Reply #6 on: June 07, 2023, 05:39:26 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
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

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
GoldenEar Triton Reference (pair), Musical Fidelity M6si, Schiit Yggdrasil-OG-B, Oppo UDP-205, Emotiva ERC-3, LG OLED65C9PUA, Salamander Synergy Triple Unit SL20, Audeze LCD-X, GIK acoustic paneling
http://halr.x10.mx/other.html

Offline P.I.

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Re: Modems and jitter...
« Reply #7 on: June 07, 2023, 07:26:10 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
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

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

 :thumb:
"A man with an experience is never at the mercy of a man with an argument." - Hilmar von Campe

Offline Nick B

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Re: Modems and jitter...
« Reply #8 on: June 08, 2023, 11:21:20 AM »

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
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

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

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.
Orchard Starkrimson Ultra amp
Supratek Chardonnay preamp
JMR Voce Grande speakers
Border Patrol SEi dac
Holo Red streamer
Hapa Aero digital coax
WyWires Silver cables
TWL Digital American II p cord
Audio Envy p cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline GDHAL

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Re: Modems and jitter...
« Reply #9 on: June 08, 2023, 12:31:01 PM »

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.

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.
GoldenEar Triton Reference (pair), Musical Fidelity M6si, Schiit Yggdrasil-OG-B, Oppo UDP-205, Emotiva ERC-3, LG OLED65C9PUA, Salamander Synergy Triple Unit SL20, Audeze LCD-X, GIK acoustic paneling
http://halr.x10.mx/other.html