Reference Headphone Amplification and Fully Balanced Analog Preamplifier Control

The Benchmark HPA4 Reference Headphone Amplifier / Line Amplifier combines Benchmark's state-of-the-art fully balanced analog line amplifier with its exclusive THX-888 headphone amplifier. Designed for uncompromising headphone listening, professional monitoring and reference two-channel systems, the HPA4 delivers exceptionally low noise and distortion while providing substantial output current and voltage for everything from low-impedance planar headphones to demanding high-impedance dynamic designs.

The HPA4 also incorporates the complete line-amplifier architecture of Benchmark's LA4, including two balanced XLR inputs, two stereo RCA inputs, balanced and single-ended line outputs, mono-sum output, programmable Home Theater Bypass and dual 12V trigger connections. Independent 256-step relay-controlled attenuators allow the headphone and line outputs to be adjusted separately or together, making the HPA4 a flexible centerpiece for both headphone and loudspeaker-based reference systems.

Highlights & Benefits

• THX-888 Reference Headphone Amplifier — Benchmark's flagship headphone stage delivers extremely low distortion, high current and wide bandwidth for demanding headphones.
• Up to 6 Watts of Headphone Power — Delivers up to 6 watts into 16-ohm headphones, 1.5 amps of maximum output current and 11.5Vrms into 300-ohm loads.
• 256-Step Relay Volume Control — Independent headphone and line attenuators provide precise 0.5dB adjustment while maintaining excellent channel balance and extremely low noise.
• Fully Balanced LA4 Line Amplifier — Includes the same balanced preamplifier architecture, analog inputs and line-level system-control capabilities as Benchmark's dedicated LA4.
• XLR4 & 1/4-Inch Headphone Outputs — Balanced-style 4-pin XLR and conventional 1/4-inch TRS connections accommodate a wide range of premium headphones.

Technology & Design

Patented THX-AAA Feed-Forward Error Correction — Benchmark's THX-888 stage uses feed-forward correction to reduce amplifier-generated distortion by approximately 30 to 40dB while remaining stable with low-impedance and difficult headphone loads.

Independent Relay-Controlled Attenuators — Separate 256-step attenuators control headphone and line output levels, allowing each to operate independently or simultaneously with precise 0.5dB adjustment.

Near-Zero Headphone Output Impedance — Extremely low output impedance minimizes interaction between the amplifier and headphone impedance curve, helping maintain tight driver control and consistent tonal response.

Ultra-Wide 0.1Hz–500kHz Bandwidth — Extended bandwidth maintains linear phase response and precise transient reproduction while helping preserve spatial information, stereo depth and image focus.

Why Buy From Us

• Authorized Benchmark Media Systems Dealer
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