Benchmark HPA4 Headphone / Line Amplifier

THE ULTIMATE HEADPHONE AMPLIFIER

Benchmark Media Systems, Inc. and THX, Ltd. have partnered to introduce the Benchmark HPA4 headphone/line amplifier featuring THX Achromatic Audio Amplifier (AAA™) technology.

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 IN 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.