Direct heated triode tube headphone amplifier

Direct heat triode (DHT) refers to triode tubes that use the cathode as the filament and will heat up the cathode directly.

The 300B is the most renowned and sought after DHT because of its dreamy tonal characteristic. HA-300 mk2 uses a matched pair of Genalex Gold Lion PX300B low-noise audio triode as power output tubes.

HA-300 mk2 uses a matched pair of Tung-Sol 6SN7GTB to compete the two stages SET amplification.

Outboard power supply minimize ripple effect, offer a clean, low-noise power to amplification output.

HA-300 mk2 uses 4x NOS 22DE4 from RCA, one of the best versions of 22DE4 available in the market.