Noise annoys. Electromagnetic Interference riding along a power line can pollute audio equipment, altering its sound. This is why we see a market for audiophile-centric mains power regenerators, power filters and deluxe power cords, each with their own differing talents in mitigating the detrimental effects of AC line noise.
On this very matter Paul McGowan of PS Audio says this:
”So noise on the AC line equaled brightness in the music. We realized music’s tonal balance was not changed, the added glare came from power line noise and increased harmonics riding on the sound, creating an edge to it.”
Transplanting this thinking to the digital audio space, a USB cable carries both data and power from the computer to the receiving DAC.
The noise that hitches a ride on the back of its 5V DC feed can pollute the DAC’s circuit, negatively impacting its sound. It’s why we now see a market for audiophile-centric USB cables and off-board battery packs that cut ties with the host computer’s DC feed and provide their own.
Manufacturers of consumer-grade computers don’t lavish their circuits with noise minimizing attention. Neither Apple nor Dell cares for keeping their circuits’ electrical noise down.
Mark Jenkins of New Zealand’s Antipodes Audio says this about computer audio noise pollution:
“Digital glare pulls your attention upwards and images are perceived to lack body and organic heft. [A good] power supply centres the perception of sound, images are fleshed out and the brain relaxes into the music.”
That’s why Jenkins designs his digital music servers to minimise noise from the outset.
“We have gone in the other direction, to avoid all noise filtering, keep the technology to a minimum and focus on minimising the noise generated by each step. We believe this way delivers much more musically engaging sound,” he continues.
However, Jenkins’ DS, DV and DX models don’t come cheap. Ditto those from Aurender and Lumin.
If your budget won’t allow for an upgrade to a more deluxe music server, filtering your existing USB port could be the next best thing.
Enter AudioQuest’s JitterBug: a US$49 dongle device that the Californian company describes as “a USB line and data conditioner that works to remove the noise and resonances inherent to USB ports, while also reducing or completely eliminating packet errors within the data stream”.
Bold claims but, as per usual, the proof is in the pudding. I first heard what the JitterBug could do at CES in January 2015.
Four months down the line, I meet with AudioQuest’s Steve Silberman in Berlin. He hands me a naked (caseless) JitterBug to road test before its official launch at the 2015 High-End Show in Munich.
On this road trip I’ve come equipped with the Astell&Kern / Jerry Harvey Layla – some of the most revealing IEMs doing the rounds right now. A second generation Astell&Kern AK120 plays the role of USB DAC. Two clicks deep into its settings and we’re up and running…
The tiny JitterBug ain’t full o’ shite: it brings greater vivacity to the midrange, improves on the Astell&Kern’s already respectable talents with separation, most notably cleaving more space around bass notes that now go deeper. Simply put: music played via the AK120 II sounds both more spirited and less synthetic when JitterBugged.
I’ve encountered improvements of a similar nature when reviewing LessLoss DFPC power cables, iFi’s USB power filter and Antipodes Audio music servers. Removing electrical noise makes music sound more natural, more believable.
The magnitude of the JitterBug’s enrichment is comparable to adding Amarra (US$35+) or Audirvana+ (US$74) to iTunes or having an m2Tech hiFace 2 (US$219) intercede between computer USB output and DAC coaxial input. JitterBug’s pricing here is keener still.
In fact, I’ve heard DAC deltas smaller than those heard between the AK120 II with and without JitterBug – yes, the message here is that simple and at a the US$49 asking, the risks of buy-before-you-try are suitably low.
Further information: AudioQuest