Classic hardware compression with a modern twist
Not just inspired. Reimagined.

The Future of Analog Gear
A4-1B combines the legendary sound and design of analog Opto-Tube compressor with modern-day workflow enhancements. Experience its signature hardware audio processing or take it a step further by accessing an array of contemporary functionalities.

A4-1B was designed to preserve vintage Opto-Tube units' highly praised smoothness and musicality. Even when pushed to the limit, the compressor remains transparent, breathing new life into vocal tracks, bass, keys, or percussion. A4-1B sounds and reacts just like the legendary hardware that inspired it allowing you to apply the legendary sound of Opto-Valve compression to your modern production.

Revolutionized Analog Power
High-quality components ensure A4-1B's superior sound and performance consistency across the whole frequency spectrum. Accurate circuit topology meticulously recreates the architecture of the legendary Danish opto-tube design for truly authentic analog compression. This all-analog powerhouse was made to last and faithfully follow the legacy it was built upon.

Custom UK-made transformers
The custom input and output transformers give this compressor a tight, punchy low-end and beautifully detailed highs, adding warmth and character, bringing out rich harmonics without sacrificing clarity.

Hand-picked premium tubes
The signature sound of this unit comes from its premium tubes, giving it a rich, musical character, adding that unmistakable analog warmth while maintaining precision and clarity.

Revolutionized modern PSU
Electricity is the heart and soul of high-end analog gear so we added an efficient, modern PSU with advanced automatic voltage adaptation for greater stability and noise reduction, that also provides DC heating to the tubes for a smoother warm-up

Unlock a game changing potential.
A4-1B is the first in a series of automated outboard analog units developed by Antelope Audio. We want to introduce high-quality audio hardware to the current generation of audio producers and artists. Thanks to our proprietary technologies these units can serve not only as traditional outboard analog gear, but also adapt to the dynamic pace of modern music production with remote control, instant setting recall, automation and more.

Supreme DAW control and automation.
The A4-1B plugin is available in VST3 / AU / AAX formats, compatible with any modern-day DAW and operating system. The unit is easily integrated into fully digital, all-analog, or hybrid studio setups. This intuitive tool makes preset management a breeze so you can apply your signature settings to various projects. Whether you A/B your mix or add a radical automation in the middle of a track - the A4-1B plugin delivers it straight to the hardware.

A new breed of motorized pots.
A4-1B features a ground-breaking proprietary motorized potentiometer engine. This not only solves the biggest downside of all analog hardware – fast preset recall for smoother workflow – but also grants convenient remote access while retaining the tactile experience of operating an outboard gear. The pots on the compressor are extremely responsive - any minor change on the digital panel is reflected immediately on the hardware, and vice versa. Modern engineers want quick, responsive, and accurate gear and that’s exactly what A4-1B achieves thanks to its custom motorized pots.