When paired with headphones, powered speakers, or a power amplifier, DragonFly operates in variable output mode. For the best results, start by setting the volume control within the music player application to maximum, then bring the computer's main operating-system volume down to around 25%. From there, use the operating-system volume control to adjust to a comfortable listening level. The reason for this approach lies in how DragonFly handles volume. DragonFly Black uses a 64-step analog volume control, while DragonFly Red, Cobalt, and Copper use a more advanced 64-step, 64-bit, bit-perfect digital volume control. In every case, the host device's system volume is, by proxy, controlling DragonFly's own onboard volume — a design AudioQuest has optimised to preserve maximum resolution and sound quality at any volume setting. DragonFly can also be used as a traditional fixed-output source, much like a CD, DVD, or Blu-ray player, connected to a standard input on a receiver or preamplifier. In this configuration it runs in fixed output mode, where overall level is governed by the master volume of the connected audio/video system. For this setup, both the music player's volume and the computer's operating-system volume should be set to maximum.

The LED on the top of DragonFly changes colour to show its current status and the sample rate of the audio being played, so a quick glance tells you what resolution you're hearing. The colours vary slightly between models. On DragonFly Black and Red: red indicates standby, green is 44.1kHz, blue is 48kHz, amber is 88.2kHz, magenta is 96kHz, and purple indicates MQA. On DragonFly Cobalt: red is standby, green is 44.1kHz, blue is 48kHz, yellow is 88.2kHz, light blue is 96kHz, and purple indicates MQA. On DragonFly Copper: red is standby, green is 44.1kHz, blue is 48kHz, yellow is 88.2kHz, and light blue is 96kHz.

Yes, DragonFly can play these files — but it performs at its best when audio is processed at its native sample rate, and DragonFly's ceiling is 96kHz. To get the full benefit from higher-resolution files, it's important to select a playback sample rate that is mathematically related to the file's native resolution. For example, a 192kHz file should be played back at 96kHz, since 96,000 multiplied by two equals 192,000. Choosing a rate that divides cleanly in this way means the computer avoids performing complex, sonically degrading conversion maths, allowing DragonFly to sound its best. It's worth noting that many modern music playback applications handle these conversions automatically on the listener's behalf.

DragonFly Cobalt is broadly compatible across all major platforms, working with Apple iOS, Windows, Android, and Linux. This wide compatibility means it can be used with everything from a desktop or laptop computer to a compatible smartphone or tablet, making it a flexible option whether at a desk or on the move.

DragonFly has a USB-A connector, but it can be connected to any USB-C device using the included DragonTail USB-A to USB-C adaptor. This means there's no need to purchase a separate adaptor or cable — DragonFly is ready to work with modern USB-C phones, tablets, and computers straight out of the box.