Do you believe this Schiit? I don't.

#61
You can't argue that these cables lengths are so short that the losses are irrelevant to return loss and then argue that 3dB of attenuation will add jitter. On such short lengths, 3dB of attenuation should not materially affect the eye pattern unless there is a lot noise being introduced into the system. Resistive attenuation by itself will not increase jitter - this will only happen if the SNR at the receiver is impacted.

And if jitter is dominated by the reflections in the system, then adding 3dB of attenuation could actually improve jitter performance.

Lastly, if any such implementation doesn't have at least 3dB of margin, then it is grossly under-designed imo..

Cheers, Joe
If the signal is attenuated by 3dB, then it is out of spec. This is not RF we are talking about, this is a specified digital signal with a 0.5V P-P voltage and timing spec. There is a maximum risetime specified, but no minimum risetime, BTW.

3dB attenuation will likely cause more jitter because the reduction in amplitude will increase the risetime. Also, the detection of the edge may not be exactly at the zero volt crossing (I'm certain it's not actually), so reducing the amplitude will place the detection point on the edges at a slower slew-rate time on the waveform.

When you are talking about picoseconds of jitter, these can easily add significantly. Even signal passing through one more buffer gate can add a few psec to the jitter.

Steve N.
Empirical Audio
 

mountainjoe

Industry Expert
Mar 25, 2015
86
0
6
Bay Area, California
eigenaudio.com
#62
If the signal is attenuated by 3dB, then it is out of spec. This is not RF we are talking about, this is a specified digital signal with a 0.5V P-P voltage and timing spec. There is a maximum risetime specified, but no minimum risetime, BTW.

3dB attenuation will likely cause more jitter because the reduction in amplitude will increase the risetime. Also, the detection of the edge may not be exactly at the zero volt crossing (I'm certain it's not actually), so reducing the amplitude will place the detection point on the edges at a slower slew-rate time on the waveform.

When you are talking about picoseconds of jitter, these can easily add significantly. Even signal passing through one more buffer gate can add a few psec to the jitter.

Steve N.
Empirical Audio
Ok, that’s a relatively low swing - I’m accustomed to working with multi-gigabit serdes that run at 800mVpp swing. These can operate down to 400mVpp reliably - that’s 6dB margin.

Cheers, Joe
 

morricab

Well-Known Member
Apr 25, 2014
2,413
47
48
Switzerland
#63
IMHO the experience you are addressing is irrelevant to this debate. I systematically bring electronic and instrumentation facts that are objectively relevant, addressing they are many times weak and too superficial to be correlated with the subjective aspects.



Yes, but galvanic isolation has its intrinsic problems, mainly that the impedance of this devices is variable versus frequency and have resonances. It is a classical compromise in instrumentation. Can you provide a link to this independent test?
Well, IMHO, you would be wrong but since these are both just our opinions I will leave it at that.

I looked for the review but could not find it (it is relatively old now) but it might be on the Monarchy Audio website still (I don't have access to this site through work due to filters). I seem to remember it was in AudioXpress.
 

morricab

Well-Known Member
Apr 25, 2014
2,413
47
48
Switzerland
#64
If you read my white paper, you will see that it is the risetime of the source that determines the minimum length. Very short, like 6 inches is good and longer than 1.25m is good. Between those lengths, most cables will add significant jitter. This has been independently ABX tested BTW.

Steve N.
Empirical Audio

What type of rise times are we talking about here? nanoseconds or longer? shorter?
 

morricab

Well-Known Member
Apr 25, 2014
2,413
47
48
Switzerland
#65
This would likely be a new driver with a new output impedance and a different risetime. If all of these are optimized, the DAC will generate lower distortion due to lower jitter.



There is no "signal boost" going on. The DIP reclocks the data and a new driver outputs this to the DAC. It is all about jitter. I have modded the DIP in past years to improve the output section and the clock. There is only so much that can be done with mods though. If you want to hear REALLY LOW jitter, try out one of my Synchro-Mesh reclockers with 7psec of directly measured output jitter at the end of my 4 foot BNC cable. You will not find anything else on the market that has jitter this low. Here is are the measurements:

https://www.audiocircle.com/index.php?topic=157348.0



Galvanic isolation is a double-edged sword. Yes, you will eliminate common-mode noise from ground-loops that can impact jitter. On the other hand, if you are using a pulse transformer, this will add some jitter, depending on the quality of the transformer. I like to do it without transformer on the output if possible, but I offer both versions on all of my products.

Steve N.
Empirical Audio
i realize there is no "boost" per se just that the signal going out has a higher level than the one coming in. I have no doubt that there are better jitter boxes out there now but I have found the Monarchy to be quite effective on most systems I have inserted it into...just goes to show how far off many of those systems are to begin with as people don't take this aspect of digital seriously enough.

Based on the test results I saw of Monarchy vs. other competitors from that era (early 2000s I think) the galvanic isolation was a big plus because the others ALL had jitter added through the power supply and the Monarchy was the only one then that really did what it said on the box.
 

morricab

Well-Known Member
Apr 25, 2014
2,413
47
48
Switzerland
#66
If the signal is attenuated by 3dB, then it is out of spec. This is not RF we are talking about, this is a specified digital signal with a 0.5V P-P voltage and timing spec. There is a maximum risetime specified, but no minimum risetime, BTW.

3dB attenuation will likely cause more jitter because the reduction in amplitude will increase the risetime. Also, the detection of the edge may not be exactly at the zero volt crossing (I'm certain it's not actually), so reducing the amplitude will place the detection point on the edges at a slower slew-rate time on the waveform.

When you are talking about picoseconds of jitter, these can easily add significantly. Even signal passing through one more buffer gate can add a few psec to the jitter.

Steve N.
Empirical Audio
And risetime is impacted because of RC time constant changes? Otherwise, simply adding a resistor shouldn't change the rise time significantly. Given that there is a maximum rise time specified are you saying that there are differences in jitter caused when the risetime is slower or faster but within that limit? I would think that jitter would arise, not by the rise time per se but in a fluctuation of that rise time. A resistor might cause a change in risetime but it should be a constant and not lead to variable risetime... or?
 
#67
What type of rise times are we talking about here? nanoseconds or longer? shorter?
Most digital sources have 2-3nsec risetimes. My devices are 400psec, much faster than pretty much anything else out there.

Steve N.
Empirical Audio
 
#68
And risetime is impacted because of RC time constant changes? Otherwise, simply adding a resistor shouldn't change the rise time significantly.
Have you tried it and measured before and after? I think you would be surprised.

Given that there is a maximum rise time specified are you saying that there are differences in jitter caused when the risetime is slower or faster but within that limit?
Yes, absolutely. The receiver creates more jitter with a slower risetime. There is always noise in the edge detection process, from thermal, from power supply, from crosstalk etc..

I would think that jitter would arise, not by the rise time per se but in a fluctuation of that rise time. A resistor might cause a change in risetime but it should be a constant and not lead to variable risetime... or?
Changing risetime impacts jitter. It is a proven fact.

Steve N.
Empirical Audio
 
#69
i realize there is no "boost" per se just that the signal going out has a higher level than the one coming in. I have no doubt that there are better jitter boxes out there now but I have found the Monarchy to be quite effective on most systems I have inserted it into...just goes to show how far off many of those systems are to begin with as people don't take this aspect of digital seriously enough.

Based on the test results I saw of Monarchy vs. other competitors from that era (early 2000s I think) the galvanic isolation was a big plus because the others ALL had jitter added through the power supply and the Monarchy was the only one then that really did what it said on the box.
Isolation is certainly important, but if I had to choose between really low jitter and isolation with higher jitter, I will choose the lower jitter, and I do.

Steve N.
 

mountainjoe

Industry Expert
Mar 25, 2015
86
0
6
Bay Area, California
eigenaudio.com
#70
Isolation is certainly important, but if I had to choose between really low jitter and isolation with higher jitter, I will choose the lower jitter, and I do.

Steve N.
Agree with this point - I think the two (psychoacoustically) predominant forms of distortion with digital is jitter and group delay distortion introduced by digital filters (though of course can also come from analog filters).

I believe the human sense of hearing is particularly sensitive to temporal distortions as these do not happen normally in nature - most folks here probably already understand this.

Cheers, Joe
 
#71
Agree with this point - I think the two (psychoacoustically) predominant forms of distortion with digital is jitter and group delay distortion introduced by digital filters (though of course can also come from analog filters).

I believe the human sense of hearing is particularly sensitive to temporal distortions as these do not happen normally in nature - most folks here probably already understand this.

Cheers, Joe
Interesting. What is a Temporal Distortion?

Steve N.
 

mountainjoe

Industry Expert
Mar 25, 2015
86
0
6
Bay Area, California
eigenaudio.com
#72
Interesting. What is a Temporal Distortion?

Steve N.
Anything that distorts audio waveforms in the time domain - jitter is one such example as it can smear the recovered analog audio signal as does group delay distortion (typically much more so than jitter).

In analog reproduction this also happens - for example there's been much debate on WBF as to the closed-loop speed control mechanisms on many TTs and the resulting audible artifacts - some folks are particularly sensitive to these and I would also characterize these as forms of temporal distortion (one aspect of this is wow & flutter but there is also a more subtle aspect of this mechanism which is the "speed hunting" behaviour that most, if not all, closed-loop speed control servo systems exhibit). In TTs this results in fine changes in pitch whereas in digital reproduction it can have a much more intrusive effect imo.

Cheers, Joe
 

About us

  • Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing