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Recommended Component 2025 – Stereophile
Editors' Choice Award - The Absolute Sound
Upgrade of an Award-Winning USB Noise Filter
You cannot hear radio-frequency (RF) noise itself, but you definitely do hear the way RF noise damages the performance of audio quality everywhere — in your home theater and stereo system, in your car, and from a computer or mobile device. What to do? Audioquest's JitterBug FMJ is the solution.
What’s old and famous, and yet brand new? Many tens of thousands of music lovers are already enjoying better audio enabled by the AudioQuest JitterBug USB Noise Filter – whether plugged into a car’s USB jack, or a laptop computer, or a USB “service-only” jack on an Ethernet streamer, etc. Now, JitterBug FMJ, with its Full Metal Jacket raises the stakes.
"Recommended Component" Honors
Stereophile honored JitterBug FMJ by awarding it the magazine's coveted Recommended Component status for 2025.
"This aluminum-bodied version of the JitterBug performs the same USB noise filtering as the original. JA [Jon Atkinson] found that using a JitterBug FMJ with the Questyle M12 USB headphone amplifier, the presentation took on a tad more transparency, coupled with a touch more ease."
Award-Winning Performance
The JitterBug FMJ won an Editors' Choice Award from The Absolute Sound magazine.
"Its mission is to reduce jitter and isolate the computer from the DAC. Judging from its sonic effects, the JitterBug does just that, offering a smoother treble, deeper soundstage, and more relaxed and natural presentation. A no-brainer recommendation for the asking price."
"Multiple JitterBugs can be cascaded (connected in series) for improved performance. You can even add a JitterBug to a non-audio device to reduce the noise on your computer’s USB bus." notes Robert A. Harley in his review of the original JitterBug in The Absolute Sound's 2016 Buyers Guide to Cables, Power Products, Accessories & Music.
"Coolest Accessory Ever"
The JitterBug does such an extraordinary job that The Absolute Sound honored it with an Editors' Choice Award in 2021.
"This has to be the coolest accessory I’ve ever used," reports Jeff Dorgay in the May 2015 issue of TONEAudio magazine. "Whether in the house or on the go, I’ll bet you fifty bucks your system will benefit from a JitterBug, no matter where you decide to install one. Highly recommended."
"I'd say just plug the damn thing in and try it out for yourself. What you'll hear, if you hear what I heard, is greater clarity, dimensionality, and generally a more natural sound," notes Michael Lavorgna in a January 8, 2015 CES post for AudioStream.com.
Try Jitterbug in Your Car
Because a car is such a very noisy RF environment, maybe the most popular place for a JitterBug is into a car’s USB jack (whether a signal input or just a power output), even when Bluetooth is used for connection to a phone.
Similarly, when streaming through Ethernet or Wi-Fi, an open USB port is a gigantic invitation to upgrade performance with a JitterBug FMJ.
Significant Noise Reduction
Whether used in series (in-line) or in parallel, JitterBug significantly reduces contamination from RF generated by a computer, car, or other device. JitterBug FMJ also thoroughly addresses environmental RF Noise taking advantage of this vulnerable interface.
New Metal Case and Other Enhancements
The new metal case is the most obvious change, though even the seemingly innocuous hinged “rubber” piece covering JitterBug’s output is crucial to JitterBug’s improved performance. That little black “door” is RF-proof thanks to the material being substantially RF-absorbing Carbon.
Employ one JitterBug in series between any computer, smartphone, NAS, streamer, or car audio system and a USB input. For an additional sonic improvement, use a second JitterBug in another unoccupied USB port (in parallel to the first), but with JitterBug FMJ’s front door closed.
JitterBug and DragonFly
A JitterBug in series with a DragonFly Black or Red always helps those wonderful creatures fly higher and faster. However, it’s best to experiment when putting a JitterBug in front of a DragonFly Cobalt – which itself employs some of JitterBug’s filtering – and so the two filters in series can help or hurt performance depending on specific equipment and context.
Regardless of which DragonFly or any other considerations, a second JitterBug in parallel is always a delightful improvement as it pulls more RF Noise off the USB power bus — which is why and how a JitterBug makes just as big an improvement even when plugged into service-only or update-only USB ports on many devices.
Making the Right Connection
JitterBug uses USB-A connections on both ends. When used with a computer or other device (or car) with only USB-C connections, AudioQuest offers a super-compact high-performance C-male to A-female adaptor and also the DragonTail flexible C-to-A adaptor (included with DragonFly Cobalt).
One can’t hear our modern world’s pervasive RF Noise itself, but the compromises it causes robs us of detail and contrast, and outright buries so much subtlety. Fight back with JitterBug FMJ.
The Noise Problem with Streaming Music
While USB (along with Ethernet) has become one of the two most important and widely adopted interfaces in the age of computer audio, it does come with its own unique sets of liabilities – mainly sound-degrading noise currents. All computing devices, whether they be laptops, phones, NAS, or even dedicated music servers, inherently generate a significant amount of noise and parasitic resonances.
In addition to this, many computers (the least offensive being laptops, as they are required to meet rigorous safety standards) can and often do contribute a considerable amount or RFI and EMI pollution onto the signal paths—all of which can easily find its way onto your USB cables and into your audio system.
This noise and interference has many negative effects. Noise-compromised digital circuitry increases jitter (dispersion in time) and packet errors, resulting in distortion that causes a comparatively flat and irritating sound. Noise- compromised analog circuitry also damages the sound’s depth, warmth, and resolution.
Use with Phone and Other Devices, Too
JitterBug FMJ can also be used with mobile phones, portable media devices, USB peripherals, and network storage/streaming devices. Many receivers, DACs, and automobiles include USB input ports that are compatible with iOS and Android devices, enabling music lovers to use a mobile phone or USB memory stick as an audio source. By first plugging a JitterBug FMJ into the associated USB input port, the playback performance of such media devices can be significantly improved.
In cases where a noisy external computer peripheral (such as a printer, camera, or hard drive) must be connected to a computer-audio system, JitterBug FMJ can be used in series with the peripheral device. Similarly, streamers, Network Attached Storage devices, and routers may all include USB ports, and all can benefit from JitterBug FMJs noise filtering.
As with many things in audio, the effect of JitterBug on the overall sound of a system may vary slightly, depending on the associated gear and application. Experimentation is enthusiastically encouraged. The results will likely prove more than worth the effort.
At JitterBug’s extremely modest price, the question isn’t whether you can afford one, but whether you can afford NOT to use one. Or even two.
