Ultra-high-precision reference line-stage preamplifier • 100% pure analog signal path • relay-controlled 256-step attenuator with 0.5 dB resolution • >137 dB dynamic range & -141 dB THD+N • balanced XLR & unbalanced RCA inputs and outputs • color touchscreen interface • Benchmark HPA4 architecture without headphone stage • manufactured in Syracuse, NY, USA
The Benchmark LA4 Line Amplifier defines state-of-the-art transparency in analog line-level preamplification, engineered to preserve delicate signal purity with zero perceptible distortion or noise. Designed as the ultimate sonic wire-with-gain, this reference line stage boasts a signal-to-noise ratio exceeding 137 dB and total harmonic distortion below -141 dB (<0.00008%), ensuring that audio signals pass from upstream DACs and analog components to power amplifiers without coloration, compression, or bandwidth limiting. Featuring an ultra-precise relay-controlled 256-step attenuator, gold-contact switching, balanced XLR and single-ended RCA I/O, bidirectional 12V triggers, and an intuitive full-color touchscreen, it delivers uncompromising dynamic range, perfect channel tracking, and studio-grade resolution.
Key Features & Innovations
Relay-Switched 256-Step Precision Attenuator — the Benchmark LA4 Line Amplifier employs low-noise precision metal-film resistors engaged via gold-contact sealed relays in 0.5 dB increments, delivering pinpoint channel tracking within ±0.03 dB and banishing stereo imaging drift across all listening levels.
Benchmark Ultra-Low-Distortion Line-Stage Architecture — achieves an astonishing -141 dB THD+N under full operating load, allowing listeners to experience the pure, uninhibited dynamic range and micro-detail of reference digital converters and master recordings.
Pure 100% Analog Signal Topology — maintains an uncompromisingly pure analog path with zero digital conversion, using digital microcontrollers strictly for isolated relay logic and touchscreen interface management to eliminate digital clock contamination.
Intuitive Color Touchscreen & Independent Gain Offsets — features a responsive front-panel color touchscreen allowing individual input balance adjustment, per-input level trimming (-20 dB to +20 dB) to match source volumes, and screen dimming functions.
Bidirectional 12V Trigger Synchronization — integrates seamlessly with Benchmark AHB2 power amplifiers and DAC3 converters via bi-directional 12V trigger jacks that transmit power on/off sequences and fault status signaling.
FAQ — Benchmark LA4
What is the difference between the Benchmark LA4 Line Amplifier and the Benchmark HPA4?
The Benchmark LA4 Line Amplifier shares the identical line-stage circuitry, relay-based attenuator, touchscreen, and extreme performance specs of the HPA4, but omits the dedicated front-panel high-power headphone amplifier stage for listeners who strictly require a preamplifier for loudspeaker systems.
Does the volume control make mechanical clicking noises when adjusted?
Yes. The attenuation system uses precision mechanical gold-contact relays to switch military-spec metal-film resistors; you will hear faint, rhythmic internal clicks inside the chassis as relays cycle smoothly between volume steps.
Can the LA4 drive long interconnect cables to remote power amplifiers?
Yes. With a very low output impedance (60 ohms balanced, 30 ohms unbalanced) and high output drive capability up to +28 dBu, the LA4 can effortlessly drive long balanced cable runs without high-frequency rolloff or slew-rate limiting.
Does the LA4 include a remote control?
An optional Benchmark die-cast aluminum infrared remote control is available, which provides direct access to volume, mute, 20 dB dim, input selection, and display brightness settings.
Why Buy From Us
Authorized Benchmark Media Systems dealer offering 100% genuine factory-sealed components with full 5-year manufacturer warranty registration
Experienced high-resolution audio specialists available to guide gain-structure optimization, cable selection, and DAC matching
Dedicated post-purchase technical support for system calibration, 12V trigger chaining, and input trimming
Fast, fully insured priority delivery in heavy-duty manufacturer protective packaging on every order
Related & System Matches
Benchmark AHB2 ultra-low-distortion stereo / monoblock power amplifier
Benchmark DAC3 B or DAC3 L reference digital-to-analog converters
Benchmark heavy-duty aluminum infrared system remote control
