iSilencer+ And JitterBug FMJ Review/Comparison – Silence Of The Jitterbug
iFi Audio iSilencer+ and AudioQuest JitterBug FMJ (Full Metal Jacket) are two very popular USB filters, a.k.a. “decrapifiers”, among audio enthusiasts. Both are marketed as simple, plug-and-play solutions to clean up USB noise (but they probably do not reduce jitter as they are passive devices without clocks – which will be explained in a forthcoming article).
Of course, there are other solutions, such as USB galvanic isolators (either electrical or optical) and analog devices such as ADUM-chip based isolators but we are not going there… we shall focus on both iSilencer+ and JitterBug FMJ in this discussion.
DISCLAIMER: I bought both devices AT FULL RETAIL PRICE with my own money. Thus, my verdicts are not affected or influenced by their manufacturers in any way.
Many folks approach this type of accessory with utmost skepticism. There are a few technical forums that have tested these devices with precision audio analysers proving they do nothing, thus labeling them “snake oil”… We are not going to debate that either.
To me, without actual listening, measurements, diagrams, and graphs tell us nothing about sound. Superior technical performance does not equate to musicality.
Both devices do what they advertised… That is to clean up noise and improve sound.
We shall focus mainly on their SONIC PERFORMANCE.
Equipment used:
- AudioQuest DragonFly Cobalt
- AudioQuest DragonFly Red
- E1DA 9038S G3
- Asus Xonar Essence STU DAC
- Topping E30/L30 stack
- KBEAR BElieve
- Etymotic ER4SR
- TRN MT1 (modded)
- Lenovo ThinkPad X1 Carbon + Foobar2000
- Self-assembled Intel i7/Asus-based desktop PC + Foobar2000
- Redmi Note 9 Pro + UAPP
- Raspberry Pi 4 Model B + Volumio
Both devices are connected at the host end. As Gordon Rankin, designer of JitterBug FMJ, puts it:
“I put the JitterBug at the host side because I want all that EMI/RFI and other BS that the computer is spitting out to stay there and not get to the endpoint.”
iFi iSilencer+
When I bought the iSilencer+, it was US$10 cheaper than JitterBug FMJ but this has changed since July 2021. Both are priced at US$59.95 now.
iSilencer+ has a plastic housing with a layer of soft rubber-coating. During installation and removal, this housing slides back and forth, which some folks may find annoying.
Compared to JitterBug FMJ, iSilencer+:
- sounds crisp with upper-midrange glare
- more open and airy
- mid-forward but rest of the frequency spectrum are thrown backward
- less bass impact, drab dynamics
- soundstage is one-dimensional
- USB noise reduction not as thorough (just a bit)
AudioQuest JitterBug FMJ
FMJ is the latest JitterBug from AudioQuest. The original had the same circuitry but no shielded enclosure. JitterBug FMJ housing is made of aluminium, feels solid and sturdy. Nothing is loose or wobbly. Size-wise, JitterBug FMJ is thicker and a slightly longer than iSilencer+.
Compared to iSilencer, JitterBug FMJ:
- overall sounds fuller and more 3D
- better dynamics and bass punch
- better depth and instrument separation
- better sense of PRAT
- cleaner, darker background
Out of curiosity and fun, I piggybacked both devices to create the “ultimate USB decrapifier”…
Host > (iSilencer+ / JitterBug FMJ) > Endpoint
Guess what happened? It actually made the sound worse. Everything sounded constricted and bone dry. I also detected slightly lowered volume gain.
So which one do I choose? Well, it depends. Ultimately, it all boils down to synergy. If your equipment is bright and cool-neutral, I suggest you go for JitterBug FMJ. If you own iFi gears, iSilencer+ does improve clarity and make the “iFi sound” less warm (or wooly).
JitterBug FMJ sounds more 3D in comparison, thus instruments and vocals are more distinctive and bodied. iSliencer+ sounds flatter in comparison. Ironically, AudioQuest DragonFly Cobalt matches the iSilencer+ better to me. Both devices filter USB VBUS/GND noise. JitterBug FMJ does it more thoroughly than iSilencer+.
Verdict
Since both devices are priced the same, it depends on availability. To many of us living in Southeast Asia, iFi products are more common and widely available. Those living in North America may find AudioQuest products easier to access.
If I have to rate both devices, I will give iFi iSilencer+ a 7 out of 10 and JitterBug FMJ an 8 out of 10. I prefer the synergy JitterBug FMJ gives to my audio gears.
USB filters are nothing new. Both iFi and AudioQuest have been making them for years. Some may find this kind of accessory unnecessary… To me, these are good to have… They DO affect sound and enhance music enjoyment to some extent. Whether or not you believe in their effects, I will leave it up to you to decide.
Hi, Thanks for great article,
Have you tried the iPurifier3 compared to these 2?
In a recent article by iFi they say the iPurifier can be better than the iSilencer.
Search Tech-notes_SilentPowerNoisebusters_Oct21.pdf
Thank you!
No, I haven’t.