Rupert Neve Designs OptoFET

The Rupert Neve Designs OptoFET Dual Band Compressor and Harmonic Processor is a fully analogue single-channel dual-topology compressor that combines a high-speed FET compressor and an optimised optical compressor into a 1U rackmount unit offering serial or frequency-split dual-band operation, variable crossover control, parallel blending, harmonic wave shaping, transformer-balanced I/O and comprehensive gain staging for advanced dynamic and tonal manipulation.

Overview

The OptoFET merges two fundamentally different compression architectures into a single processing engine that delivers both precision control and harmonic shaping. The FET section provides extremely fast transient handling while the optical section introduces slower envelope control and low-order harmonic enhancement. The unit operates either as a dual-stage serial compressor or as a frequency-divided dual-band processor, allowing independent dynamic treatment of low and high frequency content.

The design supports detailed gain staging through global input and output trims and independent make-up gain stages for each compressor. These gain structures allow the user to move seamlessly between transparent dynamic control and creative harmonic enhancement while maintaining full headroom across transformer-balanced outputs.

Dual Stage and Dual Band Processing

Dual Stage mode routes the FET and optical compressors in series, allowing progressive dynamic shaping across two independent compression engines. The global Flip control changes the order of the compressors to tailor transient response and harmonic behaviour to the source.

Dual Band mode activates a fully variable crossover that splits the signal between low and high frequency bands from 50 Hz to 500 Hz. Each compressor receives its own band, allowing independent processing of bass and mid to high frequency content. The Flip function also assigns either compressor to either frequency band, enabling precise tonal sculpting across the spectrum.

FET Compression Architecture

The FET compressor focuses on transient management and upper harmonic shaping. It provides ultra-fast attack down to 100 microseconds, variable release, switchable 4:1 and 8:1 ratios and a 125 Hz side-chain high-pass filter that preserves low frequency energy. A parallel blend control allows continuous adjustment between compressed and dry signal paths.

The GRIT mode introduces controlled high-frequency harmonic saturation by modifying the side-chain detection behaviour. This function allows subtle enhancement of articulation or aggressive wave shaping when driven through the internal gain stages.

Optical Compression Architecture

The optical compressor introduces slower attack behaviour and enhanced low-order harmonic content for density and warmth. It offers variable attack starting at 5 milliseconds, variable release, switchable 2:1 and 5:1 ratios and a 125 Hz side-chain high-pass filter for stable low-frequency response.

The BLOOM mode increases harmonic density within the low and low-mid frequency range, allowing tonal thickening and low-frequency enhancement without conventional equalisation. Parallel blending enables subtle enhancement or full parallel compression techniques.

Gain Staging and Harmonic Control

Independent input and output trims offer ±12 dB of control for driving internal stages or maintaining clean headroom. Each compressor also includes its own make-up gain stage that allows deliberate harmonic excitation in Dual Stage mode or spectral balance control in Dual Band mode. Transformer-balanced outputs preserve transient integrity and harmonic content at high operating levels.

Metering and Workflow

Dedicated gain reduction meters display real-time compression for each stage while the output meter displays final level. Fully detented 31-step potentiometers ensure accurate recall, stereo matching and predictable repeatability across sessions.

Why Choose the Rupert Neve Designs OptoFET

• Enables independent control of bass and high frequencies for clearer mixes and tighter low end

• Adds analogue harmonic character without sacrificing transient detail

• Simplifies complex multi-compressor workflows into a single unit

• Provides repeatable recall for professional mastering and production

• Delivers both transparent and creative compression in one processor

• Dual Stage serial compression with switchable processor order
• Dual Band frequency-split compression with fully variable crossover
• Variable crossover from 50 Hz to 500 Hz
• Independent FET and optical compressor control sets
• Ultra-fast FET attack down to 100 microseconds
• Optical attack starting at 5 milliseconds for slower envelope shaping
• Parallel blend controls on both compressors
• Switchable ratio options on both compressors
• GRIT harmonic wave shaping mode on the FET compressor
• BLOOM harmonic enhancement mode on the optical compressor
• Side-chain high-pass filtering on both compressors
• Independent make-up gain stages
• Global input and output trims with ±12 dB range
• Transformer-balanced analogue I/O
• Fully detented 31-step potentiometers for accurate recall
• LED gain reduction and output level metering
• Hard-wire bypass for complete signal transparency

This item, like everything we supply, comes with the complete support of our expert team. Our excellent technicians have been specifying, building and supporting studios for over twenty years. If you have any problems with installation, setup or everyday use, they’re never more than a click away, and always happy to help.

You can contact them here.