Antelope Audio – A4-1B Analog Automated Opto Valve Compressor

As Authentic as It Gets.

The A4-1B captures the essence of legendary compression. A painstakingly accurate signal path, premium tubes, and custom transformers combine for unparalleled authenticity and low-end richness. The precise opto-cell detection system guarantees precise compression characteristics, matching the authentic behavior of the original. Crafted with premium analog components, the A4-1B is not just a compressor—it’s a testament to the timeless quality of true analog engineering.

Classic Sound, Modern Engineering.

The A4-1B combines analog warmth with modern engineering for unparalleled performance. Its efficient power supply ensures stability and reliability with automatic voltage adaptation, while DC heating for the tubes minimizes noise and enhances tonal warmth. Digital control technology streamlines compression adjustments, offering faster and more precise operation. These innovations not only improve the device’s efficiency but also enhance the overall user experience, making the A4-1B a perfect blend of classic sound and modern precision for professional audio workflows.

Bringing Analog into the Digital Age.

The A4-1B also has access to the optional A4 software suite, allowing for remote control via VST3, AAX, or AU plugin, or standalone app, offering full integration into your DAW setup. Proprietary motorized knobs allow settings to be applied instantly to the hardware, while the preset system ensures easy recall for consistency across sessions and A/B testing. Attack, Release, Gain, Threshold, and Ratio can be automated directly in the DAW plugin, just like with any native tool. The extended filter section includes low pass, high pass, and band pass filters for sidechain applications, and the de-es mode with a narrow band pass filter helps clean up vocals and instruments with precision.

*The A4 software suite is available as an optional addon, as part of a monthly or annual membership plan. The A4-1B comes with 1 year of Antelope Membership for free, including the full suite of Synergy Core Native plugins, as well as all new releases and updates.

Features

Authentic Analog Sound

• 100% purely analog circuit for the audio signal

• High-quality components ensuring superior sonic performance

• Custom-designed UK transformers and high-quality tubes

• Pre-sorted opto-cell for optimal compression precision
• All tube-based push-pull amplifier
• Continuously variable attack and release time

Automated calibration systems

• Ensured compression precision over time
• Modern power supply for tube longevity and reduced humming
• Consistent stereo-link performance via calibration system
• Multiple reference levels for metering
• VU-meter for monitoring input, compression and output

A4 – Antelope Audio Analog Automation (optional)

• Remote control via VST3, AAX or AU plugin, or standalone control app
• Settings instantly applied on hardware via proprietary motorized knobs
• Comprehensive file preset system
• Automation for attack, release, gain, threshold and ratio via DAW plugin
• Extended filtering section with low pass, high pass and band pass filtering for side chain signal
• De-esser mode utilizing narrow band pass filter