"HA-10" Vacuum Tube Headphone Amplifier
The HA-10 is a world-class tube headphone amplifier designed to operate with either low impedance (Grado) or high imedance (Sennheiser) phones. The power stage is a one-tube single-ended parafeed triode output through a matching transformer, offering very low distortion and huge signal headroom. The robust power supply is fully choked for continuous current draw from the ac line. The sonics are pure, fast, and neutral, without a trace of harshness.
"I wanted to tell you how impressed I am with the [HA-10]. It is replacing a SS headphone amp that I built. The [HA-10] blows that unit away. "