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Benchmark LA4 Reference Line Amplifier/Preamplifier

Original price $2,950.00 - Original price $3,250.00
Original price
$3,050.00
$2,950.00 - $3,250.00
Current price $3,050.00
Color Choice: Black
Remote: With Remote
Includes Rack Mount?: No Rack
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Benchmark

Benchmark LA4 Reference Line Amplifier/Preamplifier

Fully Balanced Reference Line Preamplifier • 256-Step Relay Volume Control • 0.1Hz–500kHz Bandwidth • XLR & RCA Inputs/Outputs • Home Theater Bypass • Dual 12V Triggers

Reference Analog Preamplification with Exceptional Transparency and Precision

The Benchmark LA4 Reference Line Amplifier/Preamplifier is a fully balanced analog control preamplifier engineered to introduce exceptionally little noise, distortion or coloration between a source component and power amplifier. Its precision relay-controlled gain system uses high-accuracy resistors and 256 discrete volume settings, allowing repeatable 0.5dB adjustments without the tracking errors and performance limitations associated with conventional analog potentiometers.

Two balanced XLR inputs and two stereo RCA inputs accommodate DACs, phono stages, streamers and other analog source components, while balanced XLR, RCA and mono-sum outputs provide extensive system flexibility. Programmable Home Theater Bypass, input-level offsets, balance adjustment, a -20dB Dim function, dual bidirectional 12V triggers and a color touch-screen make the LA4 equally well suited to reference two-channel systems and professional monitoring environments.

Highlights & Benefits

  • 256-Step Relay Volume Control — Precision resistor networks provide smooth, repeatable 0.5dB level adjustment with excellent channel matching.
  • Fully Balanced Analog Architecture — Balanced signals remain differential through the input, gain, attenuation and output stages for excellent noise rejection.
  • Ultra-Wide 500kHz Bandwidth — Extended bandwidth supports outstanding phase linearity and fast transient reproduction.
  • Home Theater Bypass — Allows the LA4 to integrate with an AV processor while preserving a dedicated two-channel analog signal path.
  • Flexible System Control — Programmable input offsets, balance control, -20dB Dim, mono summing and dual 12V triggers simplify system integration.

Technology & Design

High-Precision Relay Attenuator — Twelve relays per output channel select precision resistor networks to create 256 accurate volume positions without placing a conventional potentiometer directly in the signal path.

Relay-Controlled Gain Architecture — A 16-step gain stage works together with the attenuation network to maintain excellent signal-to-noise performance over a wide range of playback levels.

Fully Balanced Differential Signal Path — The LA4 maintains balanced operation from XLR input through the analog output stages while also supporting conventional RCA source components.

Color Touch-Screen & Optical Encoder — A front-panel touch display provides access to programmable settings while the long-life optical volume encoder offers precise tactile control.

FAQ — Benchmark LA4

Does the Benchmark LA4 have a built-in DAC?

No. The LA4 is a dedicated all-analog line-level preamplifier. Digital sources require a separate DAC with RCA or balanced XLR analog outputs.

Does the LA4 include a headphone amplifier?

No. The LA4 is optimized specifically for line-level preamplification. Benchmark's HPA4 uses a closely related line-amplifier architecture and adds the THX-888 headphone amplifier.

Can the LA4 be used in a home theater system?

Yes. The LA4 includes programmable Home Theater Bypass, allowing a compatible AV processor to take control of front-channel volume during surround playback.

How precise is the Benchmark LA4 volume control?

The LA4 provides 256 relay-controlled volume positions in 0.5dB steps, giving the user highly repeatable control while maintaining excellent left/right channel matching.

Why Buy From Us

  • Authorized Benchmark Media Systems Dealer
  • 5% Reward Points on Every Purchase
  • Price Match Guarantee
  • Expert Preamplifier, DAC and High-End Hi-Fi System Advice

Benchmark LA4 Specifications

Product Type
Reference analog line amplifier / stereo preamplifier
Signal Path
Fully balanced analog
Volume Control
Relay-controlled precision resistor attenuator
Volume Steps
256
Step Size
0.5dB
Gain Range
Up to +15dB with deep relay attenuation
Balanced Inputs
2 × stereo XLR pairs
Unbalanced Inputs
2 × stereo RCA pairs
Balanced Outputs
Left XLR / Right XLR / Mono Sum XLR
Unbalanced Outputs
Left & Right RCA
THD
<-125dB / 0.00006%
SNR – Unweighted
>135dB, 20Hz–20kHz
SNR – A-Weighted
>137dB
Frequency Response
-0.003dB at 10Hz
-0.001dB at 20kHz
-3dB Bandwidth
Exceeds 0.1Hz–500kHz
Balanced Output Impedance
60 ohms
Output Noise
<1.9µV at unity gain, 20Hz–20kHz
Maximum Input Level
20Vrms / +28dBu
Maximum Output Level
20Vrms / +28dBu
Crosstalk
<-133dB at 1kHz
<-116dB at 10kHz
Home Theater Bypass
Programmable
Balance Control
Yes
Dim Function
-20dB
Input Gain Offsets
Programmable per input
12V Trigger Ports
2 × bidirectional
Display
Color touch-screen
Volume Encoder
Heavy-duty optical encoder
Headphone Amplifier
No
Built-In DAC
No
Typical Power Consumption
12W
Maximum Power Consumption
17W
Standby Power
0.33W
Power Supply
Internal universal power supply
Dimensions with Feet
8.65 × 3.88 × 8.33 in
220 × 99 × 212 mm
Dimensions without Feet
8.65 × 3.47 × 8.33 in
220 × 88 × 212 mm
Weight
8 lbs. / 3.63 kg
Available Finishes
Silver / Black
Brand
Benchmark

What's in the Box

  • 1 × Benchmark LA4 Reference Line Amplifier/Preamplifier
  • 1 × AC Power Cord
  • User Documentation
  • Remote Control — If Selected with Remote Configuration
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