The Benchmark HPA4 is a headphone and line amplifier featuring THX Achromatic Audio Amplifier technology.

The Benchmark HPA4 uses the flagship THX-888 amplification design to deliver outstanding audio performance. Its patented feed-forward topology eliminates traditional distortion and noise mechanisms to ensure ultimate linearity.

This Achromatic Audio Amplifier (AAA) technology reduces harmonic, intermodulation and crossover distortion by up to 40dB, resulting in a highly realistic sonic experience with no listening fatigue. The HPA4 gives you the purest sound, free from electronic noise or distortion.

The HPA4 powers headphones but also serves as a line amplifier with the highest-quality gold-contact relays for gain control, input selection and muting. The gain section boasts 256 steps of 0.5dB increments resulting in very fine level control, while the relay closure has been precisely calibrated to deliver incredibly smooth volume changes. The HPA4 also includes four independent attenuators controlling L/R headphone outputs and L/R line outputs.

Designed to be used in collaboration with Benchmark DAC3 or any other D/A converter, the HPA4 has a 100% analogue signal path for ultimate fidelity.

Benchmark’s latest headphone amplifier also features a raft of convenient features, such as its touchscreen, high-quality optical encoder, and independent on-screen mute and dim buttons. Inputs can be renamed or disabled and trimmed for input-to-input level matching.