AudioQuest JitterBug USB Filter Review

[Schmidlapper]

In the spirit of healthy debate, the first thought I had after reading the authors write up was that it wasn’t really complete. The test results demonstrate for the most part the Jitterbug doesn’t degrade the source signal, so a positive baseline. If the Jitterbug is designed to affect the USB signal of a noisy source, then laboratory grade test equipment isn’t likely to be affected all that much. In my opinion the results don’t necessarily damn the device as much as the discussions would suggest. It really hasn’t been demonstrated that the Jitterbug wouldn’t affect a noisy source enough to impact the sound, and positively hopefully.

Also a question since the discussions kind of brings it up; Red Book findings say 16/44.1 , why is 24/96, 24/88.2 or even greater capability needed? Any measurable justification?

Yes my first post, no I’ve no connection to AudioQuest, and yes thread is a little old.

Happy Holidays!

 

[Frank Dernie]

In the spirit of healthy debate, the first thought I had after reading the authors write up was that it wasn’t really complete. The test results demonstrate for the most part the Jitterbug doesn’t degrade the source signal, so a positive baseline. If the Jitterbug is designed to affect the USB signal of a noisy source, then laboratory grade test equipment isn’t likely to be affected all that much. In my opinion the results don’t necessarily damn the device as much as the discussions would suggest. It really hasn’t been demonstrated that the Jitterbug wouldn’t affect a noisy source enough to impact the sound, and positively hopefully.

Also a question since the discussions kind of brings it up; Red Book findings say 16/44.1 , why is 24/96, 24/88.2 or even greater capability needed? Any measurable justification?

Yes my first post, no I’ve no connection to AudioQuest, and yes thread is a little old.

Happy Holidays!

Welcome.
The device was tested on both good and bad DACs and it made a negligible difference to both.
The DAC with poor jitter performance still had poor jitter performance.
It also begs the question, how come any reputable maker of a DAC would release one with poor jitter performance in this day and age, so why not buy a good one in the first place so a device like this (or at least one that works) isn't needed.
Most DACs have inaudibly low levels of jitter nowadays anyway even the cheap ones.
In fact the only ones I have seen recently with really high levels of jitter, maybe high enough to create audible artefacts, have been the very expensive Metronome Technologie ones where the jitter is 100x higher than state of the art, so presumably a deliberate strategy to make them sound different.

 

[Schmidlapper]

Welcome.
The device was tested on both good and bad DACs and it made a negligible difference to both.
The DAC with poor jitter performance still had poor jitter performance.
It also begs the question, how come any reputable maker of a DAC would release one with poor jitter performance in this day and age, so why not buy a good one in the first place so a device like this (or at least one that works) isn't needed.
Most DACs have inaudibly low levels of jitter nowadays anyway even the cheap ones.
In fact the only ones I have seen recently with really high levels of jitter, maybe high enough to create audible artefacts, have been the very expensive Metronome Technologie ones where the jitter is 100x higher than state of the art, so presumably a deliberate strategy to make them sound different.

Thanks, isn’t it the source signal the Jitterbug has any influence upon, not the DAC performance, correct? AudioQuest claims are directed a affecting a noisy source signal. After base lineing the device I think the actual unit testing could have been done with a single DAC, likely the best performing.

 

[pozz]

The test results demonstrate for the most part the Jitterbug doesn’t degrade the source signal, so a positive baseline.

Remember that it's an asynchronous digital signal. The resilience against any kind of degradation is very high.

https://www.audiosciencereview.com/...performance-pc-server-interfaces-async-usb.8/
https://www.audiosciencereview.com/...s/do-usb-audio-cables-make-a-difference.1887/
https://www.audiosciencereview.com/...s-of-intona-usb-isolator-for-audio-dacs.2616/

 

[100rounddrum]

Welcome.
The device was tested on both good and bad DACs and it made a negligible difference to both.
The DAC with poor jitter performance still had poor jitter performance.
It also begs the question, how come any reputable maker of a DAC would release one with poor jitter performance in this day and age, so why not buy a good one in the first place so a device like this (or at least one that works) isn't needed.
Most DACs have inaudibly low levels of jitter nowadays anyway even the cheap ones.
In fact the only ones I have seen recently with really high levels of jitter, maybe high enough to create audible artefacts, have been the very expensive Metronome Technologie ones where the jitter is 100x higher than state of the art, so presumably a deliberate strategy to make them sound different.

Even though the device is called Jitterbug, it actually doesn’t reduce jitter. It reduces EMI and RF noise.

 

[Schmidlapper]

Remember that it's an asynchronous digital signal. The resilience against any kind of degradation is very high.

https://www.audiosciencereview.com/...performance-pc-server-interfaces-async-usb.8/
https://www.audiosciencereview.com/...s/do-usb-audio-cables-make-a-difference.1887/
https://www.audiosciencereview.com/...s-of-intona-usb-isolator-for-audio-dacs.2616/

Understood, and it maybe solely an analog effect, don’t know.

As an analogy, I’m testing a water filter, is distilled or tap water more pertinent?

 

[Raindog123]

Does Jitterbug (and such) do anything with the power over usb? Condition - filter or stabilize - it in any way?

 

[Schmidlapper]

That is the kind of information I would like to have learned from the author’s testing.

I maintain multiple typical audio sources (pc, cd, streamer) would have provided much more pertinent data than one lab grade source feeding multiple DACs.

 

[Veri]

Does Jitterbug (and such) do anything with the power over usb? Condition - filter or stabilize - it in any way?

It's right there in the review though. It seems to do *something* on power, but nothing audible in any way whatsoever.

 

[Schmidlapper]

When I say lab grade source, I assume the test devices the author employed are sufficiently accurate to produce and measure the signals necessary to reliably test the various parameters of the audio devices presented in his reports. This level of reliable accuracy and precision has to be designed into good test equipment, the best being lab grade. I doubt any personal computer maker has sufficient reason to invest this level of engineering into their USB chain, other than meeting the specification.

Another question; "Change Bias" in the typical discussion is generally presented as positive, why? Shouldn't the distribution be similar to the distribution of optimists and pessimists, "Investment Bias" should as well. If it is solely a psychological phenomena it shouldn't always manifest as positive.

So the authors base line data actually supports both the "I heard no difference", and the near zero examples of Change/Investment Bias derived, "it sounded worse" claims. Would additional testing with some typical sources provide additional data that might support the "it sounds better" camp?

 

[Veri]

Did you see the teardowns of the Jitterbug online, though? What could it possibly do? At most, addintional filtering of power, which should get cleaned up in any competent DAC, already. Thinking or believing it could do anything more, like combat some digital glare or other nasties, is mere fantasy.

 

[pozz]

Understood, and it maybe solely an analog effect, don’t know.

As an analogy, I’m testing a water filter, is distilled or tap water more pertinent?

Neither. That's an analog analogy.

You are pouring water into bottles on a conveyer belt. Water pressure sometimes fluctuates and takes more or less time to fill each bottle. The amount each bottle holds always fluctuates as well, and the nozzle leaks a little after turning off. There's a QC guy at the end of the line who checks water level and the time it takes to fill a batch.

Digital is instructions: the expected water pressure and level is the signal, and the variation is the noise. The Jitterbug is a pressure regulator that they attach just before the nozzle that the marketing department thought would impress investors. But it's a passive regulator. Basically another length of piping that is suppose give the pressure variations more time to settle. No moving parts involved.

https://www.thewelltemperedcomputer.com/Intro/SQ/Digital.htm
https://en.m.wikipedia.org/wiki/Eye_pattern

 

[mansr]

Did you see the teardowns of the Jitterbug online, though? What could it possibly do? At most, addintional filtering of power, which should get cleaned up in any competent DAC, already. Thinking or believing it could do anything more, like combat some digital glare or other nasties, is mere fantasy.

Yes, but that's ok since most of those nasties are fantasies too.

 

[Schmidlapper]

If the assessment can be based solely upon looking at the device, why test? A rock is not a good wrench, for example; a rock is not a good hammer, this might warrant some tests.

There were some indications in the results that power filtering might be an affected factor. Does the Jitterbug only have beneficial effects when a noisy source is employed? Is power a factor? I don't know, and the report didn't provide sufficient examples to answer it, in my opinion. I don't expect the author to test every type source out there, just a few indicative of typical audio sources that a Jitterbug would likely be used on. If these also show similar results it would support that the Jitterbug is ineffective at cleaning up a noisy source. The author saw fit to do this with the DAC side, just not the source side. I see that as a gross omission.

 

[AudioSceptic]

If the assessment can be based solely upon looking at the device, why test? A rock is not a good wrench, for example; a rock is not a good hammer, this might warrant some tests.

There were some indications in the results that power filtering might be an affected factor. Does the Jitterbug only have beneficial effects when a noisy source is employed? Is power a factor? I don't know, and the report didn't provide sufficient examples to answer it, in my opinion. I don't expect the author to test every type source out there, just a few indicative of typical audio sources that a Jitterbug would likely be used on. If these also show similar results it would support that the Jitterbug is ineffective at cleaning up a noisy source. The author saw fit to do this with the DAC side, just not the source side. I see that as a gross omission.

What do you mean by "not the source side"? How would you test that in a way that means anything in audio terms?

 

[Helicopter]

If the assessment can be based solely upon looking at the device, why test? A rock is not a good wrench, for example; a rock is not a good hammer, this might warrant some tests.

There were some indications in the results that power filtering might be an affected factor. Does the Jitterbug only have beneficial effects when a noisy source is employed? Is power a factor? I don't know, and the report didn't provide sufficient examples to answer it, in my opinion. I don't expect the author to test every type source out there, just a few indicative of typical audio sources that a Jitterbug would likely be used on. If these also show similar results it would support that the Jitterbug is ineffective at cleaning up a noisy source. The author saw fit to do this with the DAC side, just not the source side. I see that as a gross omission.

The source is sending a digital signal. If it is not broken then all of the signal will make it to the DAC, so you can't clean it up or make it better. That would be like running spell check on a document that has already gone through a spell checker, and has not been modified since then.

Edit: this device is like a fake spell checker that you use on documents known not to have spelling errors. I can't actually fix anything, but the spelling is still right, and unchanged.

 

[Schmidlapper]

In actual use the audio is coming from a source which is fed to the DAC via USB cable. The source is generally a CD player, PC server, audio streamer or similar. You would use one of them as an external source for the data going in to the DAC and measure the DACs output with and without a Jitterbug installed to determine if it affects the output. The testing as presented omitted any typical representative sources, which AudioQuest claims is the source of the problem they are correcting.

 

[100rounddrum]

Yes, but that's ok since most of those nasties are fantasies too.

Well, if you have a lot of source noise, the sound gets bright in a fatiguing way, and therefore you have more “nasties” than a filtered power source..

Or is the general consensus here that USB noise is a myth?

 

[Helicopter]

In actual use the audio is coming from a source which is fed to the DAC via USB cable. The source is generally a CD player, PC server, audio streamer or similar. You would use one of them as an external source for the data going in to the DAC and measure the DACs output with and without a Jitterbug installed to determine if it affects the output. The testing as presented omitted any typical representative sources, which AudioQuest claims is the source of the problem they are correcting.

That is like saying you can only review the performance of a spell checker against a dictionary on your computer, and that a printed copy of the document won't work.

Maybe you are conceptualizing digital information like analog information even though they are different. The quality of analog information changes when it is passed along, but digital information can be transmitted without any changes. That is why I used a computer spelling analogy.

 

[100rounddrum]

The source is sending a digital signal. If it is not broken then all of the signal will make it to the DAC, so you can't clean it up or make it better. That would be like running spell check on a document that has already gone through a spell checker, and has not been modified since then.

Edit: this device is like a fake spell checker that you use on documents known not to have spelling errors. I can't actually fix anything, but the spelling is still right, and unchanged.

It’s not about the digital signal; it’s the RF/EMI noise that gets transmitted from the source through USB that’s causing the extra distortion. The actual data transferred is exactly the same.