Hagerman Audio Labs: HA-10 Vacuum Tube Headphone Amplifier

"HA-10" Vacuum Tube Headphone Amplifier

Discontinued

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.

Features

Class-A operation, all tube signal path, no feedback

Drives both low and high impedance headphones

Choke input power supply

Volume control

Specifications

Gain:	2.6dB
Sensitivity:	3Vrms maximum
Input Impedance:	50k ohms
Output Impedance:	9 ohms
Bandwidth:	12Hz to 75kHz
Distortion:	<0.5% @ 1kHz
Noise:	98dB ref 1V A-weighted
Size:	10" x 10" x 4"
Power:	120Vac, 14W

Downloads

User Manual (241k pdf)

Photo of Guts (??k jpg)

Schematic (23k pdf)

Testimonials

"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. "