AudioQuest JitterBug USB noise filter Follow-Ups

Jon Iverson wrote about the JitterBug in January 2016 (Vol.39 No.10):

I've been a bit (or two) hard on the DragonFly compared to the Groove, but this JitterBug thing is something else entirely. It noticeably tightened up the details and the top end, and pushed the Apogee Groove into the Aurender Flow's orbit. A couple times at the beginning of Shawn Colvin's version of Gerry Rafferty's "Baker Street," from her new album, Uncovered (CD, Fantasy 7237415), the acoustic guitarist snaps the strings à la Michael Hedges; with the JitterBug, the effect was more focused, and jumped dynamically out from the soundstage. Then the vocals and the rest of the band come in, and the space feels bigger and more natural. Who'd have thought?—Jon Iverson

Kalman Rubinson also wrote about the JitterBug in January 2016 (Vol.39 No.10):

John Atkinson and the crew at AudioStream.com (footnote 1) have already scrutinized this little gadget ($49), and everyone seems to like it. How could I not give it a try? I was particularly interested in using it in my weekend system in Connecticut, in which resides my already overachieving miniDSP U-DAC8 multichannel USB DAC: Getting eight channels of USB D/A for $299 is amazing—and budget-priced products always seem ripe for tweaking. And, as I reported last time, UpTone's USB Regen—a USB signal regenerator intended to isolate audio peripherals from computer-system noise—had made a hugely satisfying improvement in that system's sound: Surely, the miniDSP would be a suitable mate for the bruited 'Bug.

When I asked AudioQuest for one, they sent two: AQ recommends using two—and no more—JitterBugs on each USB bus. I searched the JitterBug's box, and AQ's detailed instructions about how to use JitterBugs with various USB-connected devices, for any information about precisely what it does, and how. I found only two relevant statements:

"JitterBug is designed to remove unwanted noise currents and parasitic resonances from both the data (communication) and Vbus (power) lines of USB ports. . . .

"JitterBug's dual-circuitry measurably reduces unwanted noise currents and parasitic resonances. It also reduces jitter and packet errors (in some cases, packet errors are completely eliminated)."

Well, that's admirable—but how? JA was unable to find, in his measurements, any difference in DAC output resulting from the insertion of a JitterBug. Others have reported the same—but some have seen a change in the digital signal's "eye pattern," as observed on a digital oscilloscope. An eye pattern is a way of representing the precision of the digital pulses, which ideally should be square, thus indicating that the on-off transition is perfectly defined in time. Apparently, the JitterBug applies some kind of filter so that the squarewaves' risetime is slightly increased—the opposite of what we want if we want to reduce jitter. However, while we assume this is not good in the digital domain, it's unclear what effect such a filter might have on the DAC's analog output. Is it possible that the JitterBug is actually doing something else, and that the apparent digital compromise is merely a side effect? As long as it's reasonably square, is the eye pattern even relevant?

I don't know. But I, like others, can hear the JitterBug's positive effects on the analog output. I connected one 'Bug between the output of my server and the input of the miniDSP U-DAC8, and—with or without the UpTone USB Regen connected—the JitterBug did seem to sweeten the treble. And when I removed the JitterBug, I missed it. Though the JitterBug's effects were more noticeable without the USB Regen in the system, they were smaller than those of the UpTone accessory—which not only sweetened the treble but also, with multichannel recordings, tightened up the integration of elements within the soundstage.

I tried inserting a second JitterBug, as AQ recommends, in a different USB jack on the same server, but heard no difference. I also tried the JitterBug in my other system, in Manhattan, with the exaSound e28 DAC. The effect was similar: subtle but sweet.

The $49 AudioQuest JitterBug is the archetypal accessory whose audible benefits are unsupported by measurements—and, for that very reason, some consumers will reject it out of hand: two imponderables, both of which bother me. At the end of the day, I can only recommend you try it and decide for yourself.—Kalman Rubinson


Footnote 1: See the reviews by Michael Lavorgna and Steven Plaskin, respectively, here and here.
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ARTICLE CONTENTS

COMMENTS
doak's picture

Now combine it with an Uptone Audio Regen and hold onto your hat.
I am, simply, a VERY happy user. :D

AllanMarcus's picture

The Mac mini also has TOSLink out (via a mini plug). I'd be curious for you to try an optical cable and compare it to the USB, both with and without the JitterBug.

doak's picture

TOSlink tops out at PCM 24/96 and does not do DSD at all.
Hence, IMO, is not a "contender."

meloman11's picture

No measurable difference in jitter? Yet, Audioquest claims "measurably reduces jitter and packet errors".

BradleyP's picture

If it sounds different and there is no difference in the measurements then either your ears are fooling you OR you aren't measuring the right things OR your equipment isn't sensitive enough. Given the multiple reviews all reporting the same sonic improvements, I don't think you are fooling yourself. So, what do you think the difference is?

John Atkinson's picture
BradleyP wrote:
Given the multiple reviews all reporting the same sonic improvements, I don't think you are fooling yourself. So, what do you think the difference is?

If I knew, I would have reported that in the review. I used a very short, premium USB cable between the JitterBug and the DACs, but Gordon Rankin, the JitterBug's co-designer, has recently said that he finds it easier to measure the effect of the device by using a very long USB cable. That is something I need to try.

John Atkinson
Editor, Stereophile

doak's picture

Discussion with designers and "industry insiders" here:

>http://www.whatsbestforum.com/showthread.php?18311-AQ-Jitterbug-Measurements/page2<

John Atkinson's picture
doak wrote:
Discussion with designers and "industry insiders" here: www.whatsbestforum.com/showthread.php?18311-AQ-Jitterbug-Measurements/page2

I was puzzled by the HiFi News measurements, as Paul's eye-pattern graphs actually indicate that the JitterBug increases the risetime of the data waveform, not reduces it, which it looks as if he is saying. This actually what I would have expected given that the JitterBug low-pass filters the datastream.

However, by filtering out excessive RF noise on the data signal, this will presumably make life easier for the receiver at identifying bit transitions.

John Atkinson
Editor, Stereophile

tonykaz's picture

ghost writing for our JA?

Tony in Michigan

SN's picture

Today's measurements devices are more precise than our ears.
A big red SNAKE OIL ALERT should be shown if the gear's measurements clearly indicates no audible (positive) effect.

Regards,
your ears' and economy's best friend.

Venere 2's picture

It didn't take long for the measurement Talibans to show up.

It would seem that the editor of Stereophile, who has listened to thousands of different components over a career spanning decades, and who is also a musician; is fooling himself into believing he hears an improvement with the Jitterbug.

My ears have also been deceived by the Jitterbug. I guess I am better off believing some guy on the Internet...

tonykaz's picture

That makes it a nice little gizmo for the cable drawer if it doesn't work out.

This is Great 1980s Peg Board stuff for the Audiophile shops to help out with their paying Rent.

Back in the Day, little parts like this carried my Esoteric Audio Salon thru slow months of Summer.

Audiophiles love these little trinkets.

Monster Cable had a Full line of his kind of stuff, all were good sellers.

Jason Stoddard at Schiit is the onlyist one that po-po's all this junk.

The rest of us in the Business know fully well that Audiophiles are all about trinkets "moving the performance needle" after they shot their Wad on the Big Gear.

Litz headshell wires, tip-toes, Cramolin, directional Interconnects ( with Arrows ), Stainless, Nylon, Alum. headshell screws, Headshells by Koetsu, Fidelty Research and many others.

I had a 40' Wall of this stuff, all Audiophile rated and specific, it's amounts to a complete product line in and of itself. And, it's at least 50 points, plus nobody returns this stuff.

I even had customers that collect interconnects and speaker cables.

Phew, this IS HighEnd Audio ( the hobby ) : the Neurotic, Psychotic tendencies mechanically enabled.

But now we have Apple iTunes and DACs. Not a lot of gizmo stuff for "the" Wall.

I say: let em have their fun, nobody's gonna get hurt by this thing. Besides it's Audioquest taking over from Monster Cable, somebody gotta make and sell the Gizmos.

Noel Lee at Monster scored his Big with the Beats Headphone, it's time for somebody new.

Tony in Michigan

bernardperu's picture

Hi John, I know the Remedy Reclocker is USD$350 more expensive than the JB and it only does Toslink and Coaxial. But since you have used premium DACs, cables, etc, USD$350 is really not much.

Have you heard the Remedy? Would you prefer it to the JB?

Based on my experience (I also have the PS DirectStream), no single piece of gear (other than Speakers and matching Amps) makes such a great difference as the Remedy Reclocker, assuming one is to spend up to USD$3,000 on gear (I'd rather pair the Remedy with a USD$500 DAC than buying a USD$3,000 DAC and don't get me started on cables!)

Sorry for not talking about the Jitterbug, but they seem to compete.

If there is one question about the Jitterbug I would like to ask, it would be:

1) For my PS Directstream: Do I buy the Jitterbug + a 2m USD$50 USB cable or a USD$1,000 Audioquest USB cable?

Thanks!

doak's picture

IMO if it doesn't pass DSD, it's a non-starter.

barrysea's picture

I'm running audio files from my computer to the AQ Jitterbug, to Schitt's Uber-Bifrost and Asgard 2, through Senn HD650's, to my ears. JA was right, the music sounds great.

The Jitterbug is unbelievable, which many people will agree, but I say screw the measurements; trust your ears.

smileday's picture

I guess the computers JA used had good quality USB.

I can measure the difference in the quality of the USB digital audio outputs of my Mac mini (Late 2012) and my Toshiba laptop (Satellite P-50A). Even when I unplug the power adapter from my Toshiba laptop, the output from my Toshiba laptop is of poorer quality.
(Difference in jitter side bands or in spurious tones? I am not sure. It would be safe to say spurious tone.)

I measure it by looking at the spectrum of analogue audio output (20Hz – 20kHz, 20Hz – 50kHz, or 4kHz – 14kHz, etc.) of the connected outboard DAC. I used two $80 - $150 AD/DA converters sold in the musical instrument market: Behringer U-PHORIA UMC204HD, Focusrite Scarlett 2i2. Each product has both AD converter and DA converter.

Arthur.'s picture

Still, it's a nice product that offers an audiable improvement for basic users and for portable machines - that is if AudioQuest will ever snap out of their shell-shock and start shipping it before someone else invents something better - and many companies are planning to...

Eugene Gearty's picture

I have used the JB(X2) on 3 different systems for 2 days: My HiEnd system via a Benchmark USB DAC, my kitchen computer with a NuForce uDAC through Bose self powered speakers and my desktop office rig a Nuforce iDAC through a Zen Triode 3wt. amp.
I sincerely cannot tell the difference enough to make a $49.00 difference.
I have a considerable lot of money tied up in my HiEnd rig and have been doing this for 30 years so it's not about being cheap. Many times I have noticed improvements with various tweaks..
I'm just saying the packaging alone cost more then the JB itself.
This is NOT the way to keep the HiEnd industry on life support.
Perhaps 10 bucks or 2 for 15 bucks might make it so I don't have to pay the return shipping.

prerich45's picture

Ok, I've seen the measurements and all. I understand that science says this device does nothing, however, my ears tell me different. When I no longer have the sound of my mouse tracking, or keyboard typing, or hard drive working through my speakers.....somethings working!!!! It's dead quiet when not playing media!!!! Sounds better overall as well!!! I don't know what this thing is doing scientifically - and frankly, I don't care - it got rid of the annoying mouse/keyboard noise!!!!! Well worth the $48 I paid for it!!!!

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