Quick Hits: Antelope Audio A4-1B Compressor

Quick Hits: Antelope Audio A4-1B Analog Automated Opto Valve Compressor

For more than 20 years, Antelope Audio has been pushing the boundaries of what’s possible in analog and digital audio technology. From top-tier clocking systems to innovative outboard gear, Antelope has a history of blending classic warmth with cutting-edge control. The brand’s latest release, the A4-1B Analog Automated Opto Valve Compressor, is no exception.

At its core, the A4-1B is a fully analog optical tube compressor, built with premium components like custom-designed UK transformers, high-quality tubes, and a meticulously pre-sorted opto-cell for precise compression. But what truly sets it apart is its seamless integration of modern features like DAW control, automation, and user-configurable filters, making it a powerhouse for both tracking and mixing.

The compressor’s optional remote control software allows users to tweak settings directly from their DAW, thanks to proprietary motorized knobs that instantly apply changes in real time. Attack, release, gain, threshold, and ratio are all automatable, making it easier than ever to dial in the perfect compression settings without leaving the sweet spot of your studio.

The A4-1B is available as a standalone hardware unit with one year of Synergy Core Native access, including the A4-1B plug-in ($2995). It is also offered as a bundle with the compressor, a perpetual A4-1b plug-in license, and four years of Synergy Core Native access($3494). You can also purchase a perpetual license for the A4-1B plug-in on its own ($499).

In our latest Quick Hits video, we're at Vintage King Nashville using the A4-1B to process tracks recorded for two recent Hear The Gear sessions (Mystery Magicians and Vacuvox). Watch our video below to hear the A4-1B on performances from Bryan Reilly (acoustic guitar, electric guitar, and bass) and Olivia Dear (vocals).

Antelope Audio A4-1B Spec Check

I/O:
- 1x Analog Input (XLR & TRS)
- 2x Analog Outputs (XLR & TRS)
- 2x External Analog Sidechain Inputs (TS)
- 1x USB Type-C Port for Control and Updates
Audio Path & Components:
- 100% pure analog circuitry for audio signal
- Custom UK-made transformers, high-quality tubes, and capacitors
- All tube-based push-pull amplifier
- Pre-sorted opto-cell for optimal compression precision
Compression & Controls:
- Compress/Bypass Switch
- Dedicated makeup gain control with up to 30dB of amplification (Off, -10, 0, +10, +20, +30)
- Dedicated control for compression ratios between 2:1 and 20:1
- Dedicated threshold control starting at Off and going up to -40dB (Off, 0, -10, -20, -30, -40). When set to Off, there is no compression, but the signal still passes through A4-1B's transformers.
- Dedicated controls for precise Attack and Release:
  - Attack: Fast (0.5 ms) – Slow (300 ms)
  - Release: Fast (50 ms) – Slow (10 s)
Timing Modes:
- Timing knob dictates compression mode: Fixed, Hybrid, Custom.
  - Fixed Mode: Both Attack and Release are fixed (Attack: 1ms, Release: 15ms). Perfect for adding harmonic distortion and character to a source.
  - Hybrid Mode: Blends Fixed and Custom Modes. Attack remains fast like in Fixed Mode, but Release time varies based on the input signal. Attack and Release knobs affect the Release time.
  - Custom Mode: Allows full control over Attack and Release settings.
Side Chain Link:
- Side Chain Link knob with three settings: Off, Bus 1, and Bus 2
  - Off: The compressor acts based on the input signal.
  - Bus 1 and Bus 2: Links A4-1B to another compressor for stereo operation. The compressor with the lower threshold dictates compression behavior. Switch between Bus 1 or Bus 2 as needed.
Metering:
- VU Meter with dedicated knob for input, output, and gain reduction

If you’re interested in purchasing the A4-1B compressor or have any questions about other Antelope Audio products, contact a Vintage King Audio Consultant via email or by phone at 866.644.0160.