Solid State with Vacuum Tube Output
HeadAmp is a Virginia-based company focused exclusively on building portable and desktop headphone amps and amp/DACs. For the past nine years, however, HeadAmp has made a point of offering a series of specialized, limited production electrostatic headphone amplifiers, many of them designed by the famous headphone amplifier guru Kevin Gilmore. HeadAmp’s President Justin Wilson provides this brief history:
“HeadAmp’s first electrostatic amplifier was the KGSS (Kevin Gilmore solid state) introduced in 2003—at least five years before any competitors decided to support electrostatic headphones. The Blue Hawaii was released in 2004, and the greatly upgraded Blue Hawaii SE began shipping in 2009. The KGSS has since been discontinued to focus on meeting the demand for the Blue Hawaii SE.”
The Blue Hawaii is a large hybrid amplifier with a separate power supply housed in a smaller matching box. Hybrid in this case means that the amplifier’s early gain stages are solid state, while the output stage is built around tubes (hand-picked, matched quad, “reissued” Mullard EL34’s in the Blue Hawaii SE).