AudioQuest
JitterBug
USB-A Noise Filter

Removes RFI, EMI and noise from your USB

All computing devices — laptops, smartphones, Network Attached Storage devices (NAS drives), media servers, etc. — inherently generate a significant amount of noise and parasitic resonances. Additionally, computers contribute a considerable amount of 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 and packet errors, resulting in distortion that causes a comparatively flat and irritating “digital” sound. Noise compromised analog circuitry damages the sound’s depth, timbre and resolution.

Most obvious application is to use the JitterBug between your laptop or PC and external sound card. This way, your audio stays clear. However, the JitterBug also works the opposite direction. In case you have a USB stick, external hard drive or NAS server with all your music on it you can use the JitterBug to stop disturbances these devices create, even before they arrive at your laptop or music software. You can use them in parallel on the same device. Never use the JitterBug in series however, this will definitely create disturbances!

JitterBug’s dual circuitry measurably reduces unwanted noise currents and parasitic resonances. It also reduces jitter and packet errors (in some cases, packet errors are completely eliminated). This results in clearer and more compelling sound, music, dialog, etc. An overall more pleasant audio experience.

Review:
AudioQuest JitterBug USB Noise Filter by John Atkinson @ Stereophile.com