Rupert Neve Designs OptoFET

A Modern Approach to the FET/OPTO Duo in a 1U Format

Designed to recapture the musicality of optical compressors while adding the impact of a modern FET circuit, the OptoFET 1U combines two complementary dynamic behaviors in a single-height chassis. The FET provides a fast, incisive response capable of "disciplining" transients, while the OPTO offers a smoother, naturally musical smoothing conducive to a sense of density. The idea is not just to compress but to choose a grain and an envelope: from transparent control to true dynamic sculpting, without losing the coherence expected in a studio environment.

A Studio Compressor for Tracking, Mixing, and Bus Processing

On a vocal, the OptoFET can elegantly stabilize a level or highlight articulation, depending on the section order and harmonic mode chosen. On a bass, it helps maintain a solid, clear, and consistent low end while allowing the attack to breathe. On drums, the FET channels transients and shapes the punch sensation, while the OPTO can add sustain and "glue."

In mixing, it becomes a fine control tool on individual tracks and an expressive partner on stems. In stereo configuration (with two units), the 31-step potentiometers simplify recall and promote consistent settings, particularly useful when aiming for clean and reproducible bus processing.

Two Engines, One Workflow: From Precision to Sound Design

"Dual Stage": Stacking Characters in Series

In "Dual Stage" mode, you combine FET and OPTO in the same chain, with the option to invert the order via "FLIP." This freedom allows, for example, placing a FET upstream to control attack and tame peaks, then an OPTO to smooth and stabilize the overall feel. Conversely, starting with the OPTO can establish a soft foundation before restoring presence and definition with the FET. The result: more progressive dynamic control, often more musical, and very effective when you want to compress "more" without it sounding harsh.

"Dual Band": Processing Low and High Spectrum Separately

In "Dual Band" mode, the variable crossover from 50 Hz to 500 Hz splits the processing into two bands, with section assignment via "FLIP." This is a direct asset for maintaining a firm and stable low end without crushing brightness, or conversely, for texturing mids and highs without pumping the low end. This 2-band approach is especially relevant on bass, drum buses, synths, or dense mixes where spectral balance must remain intact during compression.

Harmonic Color: "GRIT" and "BLOOM" to Shape Timbre

The OptoFET goes beyond gain reduction: it offers wave shaping modes focused on musicality. "GRIT" emphasizes the high spectrum on the FET side to bring a sense of bite, presence, and texture. "BLOOM" on the OPTO side targets low-order harmonics and reinforces the fundamental register to thicken a source and gain density without necessarily increasing the perceived level aggressively.

Integrated Parallel Compression and Controlled Gain Staging

Each compressor features a BLEND control to dose parallel compression directly from the front panel: practical for preserving attack and natural dynamics while adding sustain and density. On the level side, input and output trims (+/-12 dB) as well as independent make-up gains (+20 dB) facilitate clean gain staging, whether you seek transparency or a bit more character. The transformer-balanced XLR output stage and 8-segment bargraph display (gain reduction and output level) provide clear, fast control suited for demanding sessions.

Technical specifications

Format	1U, single channel, rack chassis	Attack	100 microseconds to 50 ms
Modes	"Dual Stage" (series) and "Dual Band" (2 bands) with crossover filter	Release (front panel)	50 ms to 3 s
"FLIP"	inversion of OPTO/FET order in series and section assignment in 2-band mode	Release (specifications)	50 ms to 1.5 s
Variable crossover	50 Hz to 500 Hz	Threshold	+20 dBu to -15 dBu
Input trim	+/-12 dB	Ratios	4:1 or 8:1
Output trim	+/-12 dB	Side-chain high-pass filter	125 Hz, 12 dB/octave slope
Output VU	8 segments in dBu	Make-up gain	+20 dB