Ruby 3 is a high-end tube equalizer designed to recreate the authentic signature sound of the D.W. Fearn VT-5 through a new generation of hybrid modeling.
Powered by Acustica Audio’s NOVA architecture, it is built from the original unit provided by Doug Fearn and captures the full interaction between passive EQ sections and tube amplification, delivering enhanced harmonic accuracy, smoother tonal shaping, and a more natural response across all signal levels.
Ruby 3 is available in VST3, AAX, and AU formats and is compatible with all major DAWs on macOS and Windows.
The Reference: Doug Fearn’s Personal VT-5
Ruby has always been built on a single source: Doug Fearn’s own hand-built VT-5.
One of the earliest units ever made, still used by Doug as his personal reference.
Not a generic VT-5 — that exact machine.
Ruby 3 has been completely resampled using updated capture techniques based on Acustica Audio’s latest technology.
That voice is what Ruby 3 captures.
Key Features
- Original unit – Based on Doug Fearn’s own hand-built VT-5 reference unit.
- Deep Resampling – Advanced capture for greater detail and smoother response.
- NOVA Hybrid Processing – Combines Vectorial Volterra Kernels (V.V.K) with a neural processing stage to represent both low-level accuracy and nonlinear behavior.
- Flexible Workflow Integration – Suitable for use on individual tracks, buses, and mastering chains.
- Extended Control – Auto Gain, Listening Modes (Left-Right, Delta, Mid, Side), and EQ visualization, providing improved control and more accurate evaluation of the processing.
- Factory Presets – Provides preset configurations as starting points for common mixing and mastering tasks.
Ruby 3 GUI
Powered by NOVA
NOVA (Neural Optimized Volterra Audio) is Acustica Audio’s hybrid architecture and the core of Ruby 3’s preamp stage. By combining Vectorial Volterra Kernels with neural network modeling, it captures both the structural behavior and the nonlinear response of real tube hardware.
Rather than switching between models, NOVA integrates both approaches so they operate simultaneously. At lower signal levels, the Volterra component preserves the precise frequency and phase response of the original hardware, ensuring tonal accuracy and stability. As the signal level increases, the neural stage progressively contributes, reproducing the saturation and complex harmonic behavior of the circuit.
This interaction allows the processor to respond naturally to input level, maintaining coherence across the full operating range. The result is a system where structural accuracy and nonlinear behavior coexist, delivering controlled tonal balance together with realistic harmonic development.
Technical information:
• Supported formats: VST3, AAX, and AU.
• Available sample rates: 44.1, 48, 88.2, and 96 kHz.
• Compatible with Windows 10 and 11.
• Compatible with macOS 10.15 (Catalina) to macOS Sonoma (version 14.x).
• Native Apple Silicon support (Rosetta not supported).
Price and availability
Ruby 3* introductory price: €138 | (41% OFF, reg. price €235) until April 23, 2026 at 11:59 PM (CET)
Get Ruby 3 now!
*Ruby 3 is a FREE upgrade for current Ruby users!
The product is at an introductory period for the first four weeks after release or until the first official version is released; this implies that the product may receive improvements, changes, or fixes available through Aquarius Desktop updates.
Try our FREE 30-Day Trial
Note: Ruby 3's trial version includes 44.1 - 48 - 88.2 - 96 kHz sample rates.
Please remember that trials expire 30 days after authorization, and we strongly recommend not using trial products in commercial sessions or any important project.
Ruby 3 user's manual
Ruby 3 webpage: https://www.acustica-audio.com/shop/products/RUBY
