92%
Benchmark LA4 Line Amplifier
The LA4 line-level preamplifier features the best analog volume control system available at any price.
At each volume setting, relays select pairs of high-precision resistors to attenuate the music to the desired level. This system eliminates the noise, distortion, and L/R balance issues found in more conventional analog volume control systems. Traditional potentiometers and integrated electronic volume controls are the weakest link in most Hi-Fi signal chains. The LA4 removes the weak link while optimizing the system noise performance at each volume setting.
The award-winning LA4 is designed to keep noise and distortion below the 0-dB SPL threshold of hearing at each of the 256 volume control settings. No preamplifier delivers a higher degree of transparency.
The LA4 provides input selection and volume control without adding an "electronic fingerprint" to the music. Discover the difference! Listen to the music, not the electronics.
- 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 Channel - 24 Total
- Precision Make-Before-Break Timing - Prevents Switching Noise
- 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
- 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
- Unbalanced Inputs and Outputs Included
- Establishes an Optimal Gain Structure Between the DAC and Power Amplifier
- System Noise Performance is Optimized at all Volume Settings
- Matches Hi-Fi to Pro Signal Levels
- Matches Unbalanced to Balanced Signal Levels
- Perfect Match Between a DAC3 and AHB2
- Use a Single Remote to Control an All-Benchmark System
- Color Touch Screen
- Balance Control
- -20 dB "Dim" Function
- Soft Unmute
- Two Bidirectional 12V Trigger Ports
- Gain Offset Adjustments for Each Input
- Home Theater Bypass Function
- Precise, Repeatable Gain Settings Calibrated in dB
- Studio +28 dBu Input and Output Capability
- Instant A/B Switching Between Sources with Calibrated Input Offsets
- Volume Knob uses Long-Life Heavy-Duty Optical Encoder
- Long-Life Telcom-Grade Gold-Contact Relays
- Rack-Mount Version Available
The Benchmark LA4 delivers a clear, open, and uncluttered playback across the entire frequency range.
Instrumental overtones are rendered with exceptional precision and realism. Vocals are reproduced with outstanding accuracy and natural tones. Transients are fast and precise. Bass is deep and well controlled.
The ultra-linear phase response of the LA4, allows it to create a precise three-dimensional rendering of the recorded space. This space is open and uncluttered because noise and distortion are held below the 0-dB SPL threshold of hearing at all playback levels.
The LA4 may be the only preamplifier that meets or exceeds the transparency of Benchmark's AHB2 power amplifier and of Benchmark's DAC3 converter. In combination, these three components deliver the ultimate listening experience.
"Benchmark's LA4 is the widest-bandwidth, widest-dynamic-range, lowest-noise, lowest-distortion preamplifier I have encountered."
- John Atkinson, Stereophile Magazine
"By far, without question this is the best volume control I have ever encountered...
The LA4 has been widely tested with ... almost every tester reporting that the unit beats, often handily, any other ever tested in its product category, regardless of price."
- Paul Seydor, The Absolute Sound
"The Benchmark Media Systems LA4 preamplifier, AHB2 power amplifier, and DAC3 B are, individually, exceptionally transparent and well-designed audio devices. They are each top-shelf examples of their respective equipment categories in both measured and subjective performance."
- Carlo Lo Raso, Secrets of Home Theater and High Fidelity
- On/Off Momentary Switch
- IR Remote Sensor
- Color Touch-Screen Display
- Attenuation Shown in dB
- Many Programmable Features
- Long-Life Heavy-Duty Optical Encoder
- 0.5 dB per Step, 256 Steps
- Input 1 - XLR (L,R)
- Input 2 - XLR (L,R)
- Input 3 - RCA (L,R)
- Input 4 - RCA (L,R)
- Left Out - XLR
- Right Out - XLR
- Mono Sum Out - XLR
- Left Out - RCA
- Right Out - RCA
- Bidirectional Operation
- Work with all Single and Dual Direction Trigger Ports
- Time Delays Allow Noise-Free System Startup and Shutdown
- Standard 3-Pin IEC Connector
- Fuse Drawer with Two Fuses
- Auto-Ranging
- 50-60 Hz
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Professional Reviews 92/100
Deliciously Crispy
Sound Quality
95/100
Build Quality
91/100
Features Connectivity
90/100
Value for Money
85/100
The ultra-transparent, neutral Benchmark LA4 lets recordings speak for themselves, pairing a vanishingly low noise floor with precise imaging, fast dynamics, and clean, weighty bass. Erich Wetzel, Gary L Beard, and Mike Prager all praise its revealing, high-fidelity control, making it a compelling linestage for systems that value truth over coloration.
What Reviewers Are Saying
Pros
Exceptionally transparent and neutral, revealing fine detail without added coloration.
Delivers precise imaging and a wide, stable soundstage with strong depth.
Excellent bass control and dynamic impact, even at lower listening levels.
Solid build and flexible functionality, including balanced and unbalanced I/O plus a useful touchscreen interface.
&
Cons
Its strict neutrality can sound unforgiving with sibilant, compressed, or poorly recorded material.
Feature set is focused on analog line-stage duties, so buyers wanting phono, DAC, or tone controls will need those elsewhere.
SOUND QUALITY PERFORMANCE 95/100
Reviewers consistently describe the LA4 as exceptionally transparent, neutral, and revealing, with a black background that exposes fine textural detail without adding obvious color. Its balance is praised as truthful rather than sterile, and multiple writers highlight how engaging and natural it sounds despite its forensic honesty.
Transparency Resolution
97/100
This is the LA4’s calling card in the reviews. Writers call it 'exceptionally transparent,' 'the most transparent, least colored, and most revealing component' in one listener’s system, and note that it peels away haze while preserving tiny vocal and instrumental details.
Tonal Balance Musicality
93/100
The LA4 is repeatedly described as neutral, truthful, and musically involving rather than clinical. Reviewers stress that it does not sweeten or add emphasis, yet still avoids sounding sterile, with truthful timbres and a natural presentation of voices and instruments.
Dynamics
94/100
Reviewers praise its speed, slam, and dynamic contrast, with comments about fast, furious dynamic swings and effortless impact from bass and drums. One review also notes that it stays engaging even at lower listening levels, which supports a lively, uncompressed character.
Soundstage Imaging
96/100
Imaging and stage behavior are a major strength, with references to precise, stable placement, a cavernously wide stage, and excellent depth, width, and height. One reviewer even calls the imaging and soundstaging the best he has heard so far, which is strong praise in context.
Assessments of Build Quality, Usability, and Overall Propositions.
Build Quality
91/100
Reviewers repeatedly describe the LA4 as solidly built, with a substantial feel, thick side panels, and a well-executed relay volume control. The chassis is praised as more upscale than Benchmark’s more utilitarian housings, and the unit’s cool-running operation is also noted favorably.
Features Connectivity
90/100
The LA4 is well equipped for a line-stage, offering balanced and unbalanced inputs and outputs, dual 12V trigger ports, a fully balanced relay attenuator, and a useful touchscreen interface. Reviewers also mention balance control, mute functions, and a mono output, making it notably more flexible than a bare-bones minimalist preamp.
Value for Money
85/100
Reviewers call the price 'very competitive' and 'affordable' for what it does, but they stop short of describing it as a bargain. The value case is strongest for listeners who want Benchmark’s ultra-neutral sound and measurement-driven execution rather than for buyers shopping purely on low price.
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- The Music Room — online and in-store — Erie, Colorado, United States (website)
- 110Hz — online and in-store — Kielce, Województwo świętokrzyskie, Poland (website)
- Acton Gate Audio — online and in-store — Cymru, United Kingdom (website)
- Alto Music — online and in-store — Middletown, New York, United States (website)
- Atlas Pro Audio, Inc. — in-store — Sun City Center, Florida, United States (website)
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- Audiolab Stereo & Video — online and in-store — Morrisville, Pennsylvania, United States (website)
- AUDIOPHONICS — in-store — Bordeaux, Nouvelle-Aquitaine, France (website)
- B&H Photo — online and in-store — New York, New York, United States (website)
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