The problem with tube based audio is that it has so often been hijacked by people for whom the bragging rights of having a tube amplifier outweigh the benefits, or the sheer fun of building the thing.

In this video, I take a deep dive into the Cayin HA-6A Mk2, a flagship tube headphone amplifier that promises to bridge the gap between delicate IEMs and power-hungry planar magnetic headphones. While ...