In 2012 AudioQuest caused quite a buzz with its diminutive £215 DragonFly, a miniature DAC/headphone amp squeezed into a USB dongle, designed in collaboration with Wavelength Audio's Gordon Rankin and incorporating his Streamlength asynchronous USB protocol. Then the company scored a direct bullseye when it followed up with the DragonFly v1.2 [HFN Mar '14]. This not only offered improved sound quality thanks to power supply tweaks and a shortened signal path between its ESS Sabre DAC chip and the analogue output, but was also bargain-priced at just £129.
This year AudioQuest has a new "widget" commanding worldwide attention from budget-conscious audio enthusiasts playing music from their computers: the £39 JitterBug. It's another USB (Type A) dongle, a little smaller than the DragonFly, this time with a Type A socket at the other end.
PLUG 'N' PLAY
As it's an obvious partner for the DragonFly, you plug the JitterBug into a USB socket on your laptop (say), and the DragonFly into the end of the JitterBug. Simple. However, AudioQuest says it's not designed only for DragonFly owners, rather that the JitterBug will improve the performance of any USBconnected DAC.
In fact the company goes further than this, claiming it's an essential "tweak" audio set-ups. You might put JitterBugs almost anywhere you see a USB slot in a home network that's carrying audio to then simply "plugging it" with a JitterBug should improve subjective sound quality by "reducing electromagnetic and radio frequency interference", says the company.
So what exactly is it? While its name might imply that it re-clocks the audio stream to lower jitter, it's a purely passive device designed to filter out "nasties" by reducing the amount of electrical noise generated by the source (ie, the computer) travelling along a USB cable. It's a line conditioner for the 5V DC USB voltage bus (VBUS), and a signal filter for the USB data line. AudioQuest says "it also attenuates the entire signal to remove parasitic resonances, while also reducing (or in some cases completely eliminating) packet errors within the data stream".
Computer audiophiles will be well aware of specialist firms offering dual lead USB cables which separate power from data. Many listeners swear by them. But you won't find one for £39! Anyway the JitterBug approaches the fraught issue of a computer's inherently hostile environment from a different angle - by attempting to reduce noise generated by the USB bus at its source. If you simply push data from a computer to a USB DAC, AudioQuest suggests further improvement should be noticeable when using a second JitterBug in parallel (not series) on the same USB bus.
A QUIET NIGHT IN
Needles to say everybody's mileage is going to vary, since some DACs use the incoming USB's 5V DC power while many do not. If I'd hoped it might improve the performance of the little DragonFly v1.2 that lives in my laptop bag, I certainly wasn't disappointed. In fact I was completely blown away - there's no other way to say it. The sound was subjectively so much tidier and better focused that I feared I was losing my faculties… and found myself praying that editor PM would be able to measure objectively that in fact I wasn't [he did, of course - see Lab Report]
I almost fell off the sofa when hearing how the JitterBug improved the clarity and focus of John Martyn's soulful reworking of Portishead's "Glory Box" from his 1998 collection of covers, The Church With One Bell [Independiente ISOM 3CD]. Where his voice had sounded smeared, hazy and lazy now the vocals popped into focus, occupying a distinct space in the soundstage, with enhanced clarity and diction.
Playing the lovely analogue recording of Shelby Lynne's Just A Little Lovin' album [Lost Highway 0602517448254] also demonstrated the JitterBug's efficacy. Again, the sound appeared more open and better ordered, and never had I heard the printthrough of the analogue master tape so clearly resolved during the quiet opening moments of the sumptuously delicious title track.
TRANSFORMATIONS
So much for hearing it transform the sound of my "mobile" laptop PC and DragonFly v1.2 rig hooked up to my Levinson no383 and Townshend Galahad speakers; what really floored me was observing how it also improved the performance of my living room set-up of Mac mini and T+A DAC 8 [HFN Oct '12].
Time and again I found it made music sound more natural, more believable. It's easy to relax and enjoy one's system when playing beautifully balanced recordings. However, where the JitterBug scored time and time again - and what impressed me the most - was in the manner in which it appeared to clean up less-than-stellar recordings, seemingly removing any fatiguing "sizzle" or hash.
It worked wonders on Pharrell Williams' "Happy" from 2014's G I R L [Columbia 88843 05507 2] which, more's the pity, is a typically compressed and dynamically squashed example of what is otherwise a wonderful slice of "perfect pop". While it didn't transform "Happy", it certainly helped ameliorate the cacophony and tidied it up.
Similarly when revisiting some classic Holland-Dozier-Holland songs from 1968 - the title track from Diana Ross & The Supremes' Reflections [Motown/Universal Japan SHM-CD, UICY-75226] - the sound was altogether cleaner and better defined. What a bargain upgrade!
HI-FI NEWS VERDICT
Considering the modest £39 asking price, it's impossible not to be impressed by the sonic improvement offered by the JitterBug between a computer and DAC. Heck, I spent that much last weekend on a takeaway curry for the family. The curry's long gone; the JitterBug remains in my computer rig - and it's staying put! Indeed, I'm looking forward to hearing what happens when I "double up" with another one.