The 6 Best USB Filters
Editor's Notes
January 05, 2021:
Unfortunately, the SBooster VBus2 is extremely hard to get your hands on at this point, so we've removed it from contention. It's been replaced with the Cablemax Isolator, which does a good job of putting up a barrier between electronics and their USB data source. It can minimize or eliminate unwanted noise, and it can prevent faulty electronics from frying a PC's USB port.
For simple, non-powered solutions, the IFI iSilencer+ has been moved into the top spot because it comes in Type-A and C version, as well as a Type-A to C converter model. The IFI iPurifier3 remains one of the most reasonably priced USB-B options, while the IFI Nano iGalvanic should satisfy the most demanding audiophiles, even if they're stuck with a high-interference system environment.
March 29, 2019:
Depending on what your exact situation is, there are handful of different ways to filter a USB signal and eliminate various types of noise. The most straightforward and common among owners of compact DACs are the AudioQuest and the IFI iSilencer. They're small and reasonably priced dongles, and you can use up to 2 or 4 per computer at one time, respectively. For most everyday applications, they can essentially level up a mid-range DAC. If you're running audio from a high-end amplifier, check out the iPurifer, which is a full-featured, 3-way filter that can help to make a home audio setup sound pristine. If you're even more demanding than that, and must have the best, the IFI iGalvanic is probably the way to go. It's really expensive, but if you're bogged down with different signals cutting into your transmission quality, it can really improve how your amplifier sounds, while eliminating a wide range of artifacts as well as ground loop hums. Speaking of ground loops, if that's where your problem lies, the iDefender may be a godsend. It won't fix every ailment that can afflict a USB signal, but it might just do the trick, and with its separately available power supply, you won't even lose USB power functionality to the DAC. If you know that your problem lies in mismatched signal clock speeds, the Wyred 4 Sound Recovery will do a great job of matching them, and in doing this it can bring out exceptional bass and treble response that you otherwise never would have heard. And if you're looking for something simple and cheap that you can throw in your pocket to simply remove the USB power from the equation, the SBooster VBus is a good way to do it.