Kamil Owczarz of Ear Fidelity first read about the Campfire Audio Andromeda under a nickname, the "In-Ear HD800," borrowed from Sennheiser's HD800 headphone, and he wanted to hear a pair someday. At High End Munich in 2023 he heard the whole range and met Ken Ball, the founder. The Andromeda is built on balanced armatures, tiny drivers first made for hearing aids. Most earphones of this kind tune each driver with a tube and filter, and Everyday Listening explains that the tube can add reflections. Campfire puts a small 3D-printed chamber right at the output of the treble drivers instead, and the site says the more direct path extends the treble and improves detail. Campfire calls its approach "organic tuning" and says it doesn't chase a single target curve. Ear Fidelity found that the Andromeda never gave up "pleasure and timbre" for a little more detail. Campfire suits listeners who choose an earphone for its character.

The Andromeda is the natural place to start, since Campfire has refined it through 13 versions, and Ear Fidelity sends listeners who want a neutral, detailed sound to the Solaris Stellar Horizon. Both are so easy to drive that a quiet source matters more than a powerful one, because any background noise from the amplifier comes through. Indiana Lang of Secrets of Home Theater and High Fidelity heard hiss from amps he had never heard hiss from before, and his quietest pairing was a Schiit Magni Heretic. Everyday Listening suggests a neutral to bright source for the warm Andromeda Emerald Sea. The dual-planar Astrolith is the exception, and Bloom Audio says it wants more power than a phone dongle gives. Fit matters too. Lang found that without a good seal the highs sound hollow and the bass disappears, and the host of Amplify Audio Reviews has yet to find a Campfire model he didn't like more with aftermarket tips. For something easygoing, Ear Fidelity calls the Fathom "more forgiving, more universal."

Before Campfire, Ken Ball ran ALO Audio in Portland, making cables and portable amplifiers such as the Continental Dual Mono. Campfire started in 2015 with the four-armature Jupiter, the single-armature Orion and the Lyra, which put a beryllium-coated dynamic driver in a ceramic shell. The Andromeda followed in 2016 in a faceted aluminum shell anodized a green that Campfire says came from Pacific Northwest landscapes. Ear Fidelity counts 13 versions of it in all, and the Andromeda 10 of 2025 marked ten years with ten armatures. MajorHiFi calls Campfire one of the brands "that audiophiles cut their teeth with" in earphones. Ball told Guy Lerner of The Headphone List that he wrote up the triple-dynamic Trifecta "in a napkin." The Clara began when John Darko introduced Ball to Alessandro Cortini of Nine Inch Nails, and about a dozen tuning revisions passed between them before it was named after Cortini's daughter. Campfire is about ten people in southeast Portland, where its three engineers, Ken, Vali and Ben, have designed every model since the beginning.