Pack all your troubles in your old jitterbug and smile, smile, smile. Is the Audioquest Jitterbug a problem solver or snake oil as some say? The Audioquest Jitterbug looks like a thumb drive on steroids with a USB A socket on the rear. Just plug it into the computer and connect your USB d/a-converter on it and you’re in audio nirvana. I came across three kinds of opinions on the Jitterbug: it’s great, it’s snake oil and “well, it does something”. The Jitterbug is nothing more — or less — than a device that cleans up the power line and the signal lines of the USB bus. It holds purely passive choking filters and therefore can have a positive effect on the sound when dimensioned correctly. Even on d/a-converters that do not use the 5 volts DC power line that is a part of the USB connection, the ground will be connected. Audioquest claims it measurably reduces jitter and packet errors.
Jitter measurements on the audio signal did not show any improvement and unfortunately I do not have equipment to measure on data channels. So, time to call upon the best equipment, the ears. Eating the pudding The first trail I did with the 2011 Mac Mini with SSD system drive, Wester Digital Thunderbolt MyBook drive holding the music and my Set 1 with the Chord QDB-76 connected via USB. It did improve the sound. Especially voices and piano sounded more natural, less stressed. But don’t be mistaken, the differences are very pleasant but subtle.
By the way, see the link in the top right corner for a description of my reference sets. The second trail was one of brutal force: a Raspberry Pi with switching power supply, driving a NuForce Micro DAC 3 in my Set 3. Here the jitterbug couldn’t improve anything. Was this because of the quality limitations of Set 3? No, when I replaced the switching power supply with the SBooster Best of Two Worlds power supply, the sound immediately improved.
Don’t forget that the NuForce d/a-converter is fed from the same power source as the Raspberry Pi and that the power has to travel through the Raspberry Pi. Adding the Jitterbug did give some improvement now, here not only in the mids but also in the highs The third trail was done in my Set 2 using a Raspberry Pi with HiFiBerry Digi+ interface and the SBooster Best of Two Worlds power supply connected directly to the Digi+ board. See the link in the top right corner for a description of the DigiPlus and Best of Two Worlds combination. Here the Jitterbug gave no improvement which isn’t a surprise since the DigiPlus was powered directly from the clean linear power supply while the Jitterbug was further away on the Raspberry Pi USB power line. Power games.
Now, let’s evaluate what we know. On a decently designed computer, like the Mac Mini, it did improve the sound. The Mac Mini uses a switching power supply but not all switching power supplies are bad. Several high end manufacturers, like Linn, use switching power supplies. But I also know from reports that replacing the Mac Mini’s built in power supply by a linear power supply does improve the sound. Still the Jitterbug managed to improve the sound quality. The Raspberry Pi with the el cheapo switching power supply suffered from the poor signal to noise ratio of the power supply so badly, the Jitterbug couldn’t help out. When the power supply was replaced by the costly but very clean SBooster Best of Two Worlds power supply, the power lines cleaned up and the Jitterbug could provide a further improvement. Some measurements I usually don’t bug you with measurements but these are so illustrating.
They show the pollution level that’s found in the USB power line. I cut a USB cable, took the two wires that carry the 5 volts DC and connected them to the measurement input of the Audio Precision measuring set on one side and to a USB socket on the Raspberry Pi on the other side. Then I measured the noise spectrum. In other words how loud the signal is at a large numbers of frequencies between 5 Hz and 22 kHz. Ideally there should be no output but electronics can never be that perfect. But the lower the line, the less pollution is present in the 5 volts DC. The blue curve shows the result using the SBooster Best of Two Worlds to feed the raspberry Pi. The green line shows the about 10 dB more polluted result coming from the el cheapo switching power supply.
But when I inserted the Jitterbug between the USB socket on the raspberry Pi and the cable to the measurement set, the measurements gave the same results. So if the Jitterbug does some heavy filtering, it must be above 22 kHz. The wrap Does the AudioQuest Jitterbug work? Yes, but it’s a device that’s designed to further improve a set that is already good sounding. Did you place your loudspeakers properly? Check my video on loudspeaker placement, you find the link in the top right corner. Did you check the polarity of the power lines for lowest ground potential and did you use proper cabling? Ah. that’s yet another activity for my bucket list: explaining the things I just mentioned. But anyway, only when your system doesn’t have big errors, the Jitterbug can really improve the sound. Some will find it impressive, others will find the improvement modest. That depends on the level of your equipment and how critical you are yourself. Either way, the 49 euros are well spent, even when you consider the improvement modest.
And if you don’t hear any difference, you know you have to improve how you have set up your stereo. I started the Hans Beekhuyzen Project, of which the Hans Beekhuyzen Channel is a part, to help you with that. So follow my Facebook or Google+ page or my Twitter account to stay informed. You can also post questions there but please view my Questions video first. See the link in the top corner. You’ll find the information below this video in Youtube. If you liked this video, please give it a thumbs up and tell your friends on the web about it. I am Hans Beekhuyzen for the HB Channel, thank you for watching and see you in the next show or on theHBproject.com. And whatever you do, enjoy the music.