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ANTELOPE AUDIO  |  SKU: 24112

A4-1B Analog Automated Opto Valve Compressor - Complete

Mastering Compressors

Full analog opto-tube path, DAW plugin control, motorized pots, preset recall, sidechain filters, UK transformers, auto calibration, rich harmonic tone

$2,815.00 CAD $4,425.00
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Description

The Antelope Audio A4-1B is a groundbreaking analog hardware compressor that seamlessly merges vintage opto-tube warmth with cutting-edge digital control, giving audio professionals the best of both worlds in a complete, fully integrated system. Engineered to preserve the smooth, musical compression characteristics of legendary optical-tube units, the A4-1B elevates analog gear with modern-day workflow features that redefine studio flexibility.

At its core, the A4-1B features a hand-built, all-analog signal path, including custom UK-made transformers, hand-selected vacuum tubes, and a meticulously accurate circuit topology based on the iconic Danish opto design. This results in an unmistakably rich, warm tone that adds depth and character to vocals, bass, keys, and drums - with transparency and musicality even at high compression ratios.

Where the A4-1B truly breaks new ground is in its full digital integration. Through its dedicated VST3, AU, and AAX plugin, users gain precise remote control, DAW automation, instant preset recall, and even real-time motorized potentiometer movements that mirror plugin adjustments physically on the hardware. Features like sidechain filtering, de-essing, and A/B comparison are seamlessly built into the plugin, giving producers surgical precision in any modern production scenario.

Features

Authentic Opto-Tube Compression: 100% analog signal path with hand-picked tubes and custom UK-made transformers for warm, musical dynamics.

Complete Plugin Integration: Includes perpetual license for the A4-1B plugin (VST3, AU, AAX) with full control of hardware parameters inside your DAW.

Motorized Controls with Automation: Proprietary motorized potentiometers instantly respond to DAW automation and plugin adjustments.

Instant Preset Recall & A/B Switching: Save unlimited presets in your DAW and switch between settings for fast comparisons and consistent recall.

Advanced Sidechain Filtering & De-Essing: Built-in plugin filters (HP, LP, BP) for precise frequency control; includes vocal de-essing mode.

Automatic Calibration System: Built-in self-calibration maintains compression accuracy and stereo consistency over time.

Selectable Compression Modes: Choose from fixed, manual, or hybrid timing for flexible response to vocals, bass, keys, and more.

Multiple Reference Levels: Selectable metering references (-10 dBu, 0 dBu, +4 dBu, +20 dBu) and VU monitoring for optimal alignment.

High-Performance Specs: +24 dBu input/output headroom, < -80 dBu noise floor, and wide 20 Hz " 20 kHz +/- 1 dB response.

Modern Power Supply: Auto-switching PSU with DC tube heating for lower hum, smoother startup, and global voltage compatibility.

Specifications

General Specification

100 percent analog signal path

All tube-based push-pull amplifier circuit

Pre-sorted opto-cell for precision compression

Custom UK-made input and output transformers

Premium hand-selected vacuum tubes

High-quality components throughout

Frequency response: 20 Hz to 20 kHz ±1 dB

Input impedance: 10 kOhm differential

Output impedance: less than 60 Ohm

Maximum input level: +24 dBu

Maximum output level: +24 dBu

Noise level: less than -80 dBu

Compression Parameters

Continuously variable ratio: 2 to 10

Threshold range: off to -40 dBu

Attack time: 0.5 ms to 300 ms

Release time: 50 ms to 10 s

Gain range: off to +30 dB

Modes: fixed, manual, hybrid

Monitoring & Calibration

VU-meter modes: input, output, gain reduction

Reference level selection: -10 dBu, 0 dBu, +4 dBu, +20 dBu

Built-in opto-cell test and calibration system

Calibration support for stereo-linked operation

DAW Control & Automation

Motorized potentiometers for remote control

Full plugin control via VST3, AU, AAX

Real-time synchronization with hardware unit

Plugin automation of attack, release, gain, threshold, ratio

Preset management system with A/B comparison

Plugin recall inside DAW projects

Extended filtering: high-pass, low-pass, band-pass

De-essing with narrow band-pass side-chain filter

Power & Environmental

Power: 95 V to 245 V, 50/60 Hz

Modern PSU with automatic voltage adaptation

Operating temperature: 0 to 50 C

Physical Specifications

Unit dimensions (H x W x D): 88 x 483 x 252 mm

Unit weight: 4.4 kg

Box dimensions (H x W x D): 140 x 640 x 350 mm

Shipping weight: 6.5 kg

Included in Complete Version

A4-1B analog compressor

Power cable

USB-C to USB-C cable

Get Started leaflet

A4-1B Plugin Perpetual License leaflet (Complete edition)

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