The PHDA02 is a reference-class headphone amplifier with three modes: Stereo, Mono, and Dual Mono.

In Stereo mode, L/R signals are sent to each headphone, with volume controlled by the Stereo/Left knob. Mono mode combines L and R channels into a single signal for both earphones. Dual Mono mode allows independent volume control for each channel.

Compatible with headphones between 8 and 200 Ohms, the PHDA02 uses a switchable transformer for optimal impedance matching, enhancing performance and signal-to-noise ratio.

The amplifier features combo input sockets for balanced XLR and unbalanced TS connections and parallel XLR outputs for daisy chaining. It operates within mains voltage from 100 VAC to 240 VAC.

Equipped with low-noise op amps, the output amplifiers have discrete power transistors mounted on heat sinks. The unit's dimensions are 1U (1.75 inches) high and 9.5 inches wide.