The AudioQuest JitterBug isn’t a new pair of headphones with better speakers. It’s not an amp to boost the robustness of the sound being delivered to your headphones, and it’s not a DAC, trying to deliver the highest-resolution signals to your amp and headphones. It’s much more esoteric: it’s a filter for your USB port.
First, backing up: if you’re getting into higher-quality sound, delivered from your laptop or desktop computer, the first thing you learn is that you don’t want to listen to the music from the mic port. The on-board mic ports on most computers are using a very basic DAC (digital-to-analog converter) to change the bits of your sound files into analog audio signals going into your headphones or speakers. Instead, you plug a higher-grade DAC into a USB port. Then you probably plug an AMP into that, to boost the resulting signal (or the DAC and Amp are a combo unit). And then you plug your headphones/speakers into that for listening nirvana.
But the audiophile engineers at AudioQuest, ever looking for ways to improve the resulting sound just a little bit more, hit upon one of the weak points in this sonic workflow: the quality of the signal coming out of the USB port. Most people just think data is data, and if you’re getting a steady stream of 1s and 0s that isn’t doing anything special until the DAC turns it into analog signals, then what can you do to improve it