Rupert Neve Designs 5046 OptoFET

The OptoFET is a highly versatile analogue compressor and wave shaper, combining a newly-designed FET compression circuit with an optimized Optical compression circuit into a single rack space. There are two primary compression modes: in Dual Stage mode, the FET and OPTO compressors are used in series for complete dynamic control over critical sources, accomplishing a common recording & mixing technique with ease. In Dual Band mode, each compressor is assigned to either a low or high frequencyband that can then be processed independently, which expands the tone-shaping and dynamic control of the OptoFET into uncharted territory.

From transparent vocal smoothing to extreme envelope shaping with massive harmonic texture, the OptoFET offers seemingly infinite creative control. Not only does each compressor have fully variable attack, release, threshold, make-up gain and parallel blend controls - plus side-chain high pass filters and special 'GRIT' and 'BLOOM' harmonic modes - the OptoFET also includes global controls to flip the order of the two compressors in Dual Stage mode, plus a unique variable crossover control to fine-tune the compression across upper and lower frequency bands in Dual Band mode. And
though it is a single-channel unit, a pair of OptoFETs in dual mono - with 31-position fully detented controls - can add massive impact to stereo stems, groups, or even full mixes.

Intended for tracking, touring, mixing, mastering & sound design, the OptoFET provides immense control over the dynamics and tonal shape of your source. Compress creatively with the OptoFET.

For many years, the engineering team at RND has experimented with FET compressor designs - but it wasn't until the OptoFET concept was solidified that releasing our first FET circuit felt 'right'. While this FET compressor has some familiar characteristics, including ultra-fast attack times and common ratio settings, there are also several features that make it instantly feel like a Rupert Neve Designs product and nothing else.
To start with, all variable controls for the OptoFET are via high quality, 31-detent potentiometers, standard to most of our current products. The FET compressor includes variable Attack (with the fastest time being a blazing 100 microseconds), Release, Threshold, +20 dB of Make-up Gain and a parallel Blend control from 0% (dry) to 100% (wet). Ratio can be set to either 4:1 or 8:1 and the 125Hz S/C high pass filter can be toggled on to leave the low end of a source untouched.

To further expand the OptoFET's creative capabilities, a unique new 'GRIT' mode transforms the FET compressor into a powerful wave shaper, introducing ample harmonic distortion focused in the upper frequency range. GRIT can be used to either
slightly accentuate sources so they 'pop' in just the right way or transform them into something entirely new. GRIT is also especially useful when combined with the blend control to achieve an exacting amount of distortion character for a wide range of
sources.

RND has created several optical compression circuits over the years - including the Comp in the wildly popular MBT (Master Bus Transformer) - but the circuit in the OptoFET was further developed to be the ideal complement to the faster, high-frequency focused FET compressor. In contrast, the OPTO compressor generates low-order harmonics while also having much slower attack and release settings.

For controls, the OPTO compressor includes variable Attack (starting at 5 milliseconds), Release, Threshold, +20 dB of Make-up Gain and parallel Blend controls, arranged in the same way on the front panel as the FET section. Ratio can be set to either 2:1 or 5:1, and it also includes a 125Hz S/C high pass filter.

Where the FET section has its new 'GRIT' mode, the OPTO section contains another unique new mode called 'BLOOM'. With BLOOM engaged, the low-order harmonics increase significantly, instantly making sources warmer, rounder and more pronounced
in the low end. BLOOM can help make final adjustments without the use of a traditional EQ, especially when used with the Blend control.

Some of the OptoFET’s most unique & powerful features lie in the global control section. In this section, the serial order of the 2 compressors can be 'flipped' while in Dual Stage mode. However, the OptoFET can also become a Dual Band compressor by simply pressing the 'X-OVER IN' button, which engages the Crossover filters and the corresponding 'CROSSOVER' variable frequency control. With this mode engaged,
each compressor is assigned to either the low or high frequency band, allowing for independent processing of both bands simultaneously. The variable frequency selection control dials in exactly where the crossover is applied, from 50Hz to 500Hz.

The 'FLIP' button also works while in Dual Band mode, assigning the FET or OPTO to process either frequency band as desired. This can be especially helpful for bass
sources, providing complete control over the low-end while boosting the mids and highs to dial in the perfect amount of string noise and texture.

The OptoFET contains several gain staging options, starting with +/- 12dB input & output trim controls, ensuring the compression stays smooth & transparent. Alternatively, they can be used to drive the compressors, bringing out novel and interesting harmonic tones without clipping the custom transformer-balanced output stage. In addition, each compressor has its own make-up gain, with one driving into the next in Dual Stage mode. In Dual Band mode, the make-up gains can be used for tonal balance adjustments ranging from subtle to dramatic. As with most exceptional compressors, many of the controls and settings are gain dependent, which is why the OptoFET begs for experimentation at every turn.