HeadAmp Gilmore Electrostatic Headphone Amp

General Information

The Gilmore Electrostatic Headphone Amplifier (KGSS) is HeadAmp's solid-state electrostatic amplifier. This current-domain design by Kevin Gilmore drives all Stax headphones as well as Sennheiser Orpheus electrostatic phones with a special connector, available by request.

The amplifier is housed in a sophisticated brushed aluminum enclosure that is available in black or silver. A balanced input and unbalanced input can be connected to the amplifier and selected by a switch. A pair of DACT stepped-attenuator volume controls are standard in the KGSS as are the custom machined knobs.

A custom-made toroidal transformer feeds the dual high-voltage power supply that the KGSS runs off of. A separate 580 Volt supply provides the bias voltage for the electrostatic headphones.

The KGSS provides extremely detailed, transparent sound to your electrostatic headphones. Only the highest quality components are used throughout the construction of this amplifier.


Device Type Solid State (JFET, Bi-Polar Transistors)
Frequency Response 5Hz-45KHz +/-0.1dB
Signal-to-Noise Ratio inaudible
Total Harmonic Distortion <0.008%
Gain 1000x / 60dB
Input Impedance 50K ohms
Output Voltage 1200 Volts peak to peak
Inputs/Outputs 1 XLR input, 1 RCA input, 1 Stax Pro-bias output
Bias Voltage 580VDC (adjustable)
Operating Voltage 100VAC, 120VAC, or 230VAC
Power Consumption 80 Watts
Chassis Dimensions 16.5 (L) x 16.0 (W) x 4.0 (H) inches
Weight 18lb / 8.0kg