Benchmark HPA4 - Silver

The HPA4 features the Benchmark-exclusive THX-888 headphone amplifier. This is Benchmark's flagship headphone amplifier. It also marks the pinnacle of the THX headphone amplifier family. The THX-888 circuit board is manufactured by Benchmark.

Like our AHB2 power amplifier, the THX-888 features the patented THX-AAA feed-forward topology. The THX-888 keeps noise and distortion below the threshold of hearing, even when driving the most difficult headphones.

The award-winning HPA4 packs power, speed, and control into a package that includes all of the functions and features of our LA4 line-level preamplifier.

The headphone and line outputs are controlled by independent 256-step relay-switched attenuators. This is, without question, the best analog volume control system available.

Feed-Forward Error Correction

• Much Faster than Feedback
• Eliminates Zero-Crossing Distortion
• Inherently Stable, Non-Recursive Correction
• Stable into Any Phase Angle
• Stable when Driving Very Low impedances
• No Rise in THD when Driving Low Impedance Headphones

Patented THX-AAA Technology

• Flagship THX-888 Headphone Amplifier
• 30 to 40 dB reduction in THD
• Keeps THD+N Below 0 dB SPL at All Times
• No "Electronic Fingerprints" on the Music
• Accurate Impulse Response Into all Loads
• 135 dB SNR

Extended Frequency Response

• Ultra Wide 0.1 Hz to 500 kHz Response
• Bass is Delivered Without a Phase Shift
• Fast, Distortion-Free Transient Response
• Linear Phase Response
• Accurately Reproduces the Audio Waveshape
• Precise Rendering of Stereo Width and Depth
• Focused 3-D Stereo Image

Unique Features

• High Output Current - Drives Low Impedances with Ease
• High Output Voltage - Ample Headroom to Dive Inefficient Headphones
• 0-Ohm Output Impedance - Maintains Tight Control of Drivers
• Fault-Detection Circuit- Protected against Short Circuits and Overloads
• Dual Outputs - XLR4 and 1/4" TRS
• Independent Line and Headphone Balance Controls

Relay-Controlled Volume

• High-Precision Low-Impedance 256-Step Attenuator
• Low-Noise 16-Step Input Gain Stage
• Control Range is +15 dB to -127.5 dB in 0.5 dB Steps
• High Precision Laser-Trimmed Thin-Film Resistors
• 12 Relays per Output - 48 Total Including Line Outputs
• Precision Make-Before-Break Timing - Prevents Switching Noise

Fully-Balanced LA4 Line Amplifier

• The HPA4 Includes all LA4 Features
• 2 Pairs of Balanced Line Inputs
• Fully-Balanced Differential Input Amplifiers
• Fully-Balanced Relay-Controlled Gain Stage
• Fully-Balanced Relay-Controlled Attenuation Stage
• Fully-Balanced Output Line Drivers
• Left, Right and Mono - Balanced Line Outputs

DESIGNED, ASSEMBLED, AND TESTED N THE USA

This Benchmark product was designed, assembled, and tested in the USA using USA and imported components. Most major components are made in USA.