The FEA Labs Opti-FET Compressor is a compressor pedal announced on May 19, 2010, with an MSRP of $245.001. Its name describes its design: optical elements handle the compression dynamics, while discrete FET (field-effect transistor) amplification carries the audio path1. No Treble described the same combination as optical elements for compression alongside 100 percent "class A" FET-discrete amplification2.
How the circuit works
The Opti-FET uses optical elements to sense and control the compression dynamics, and FET discrete amplification in the audio path itself1. In a compressor, the side-chain is the part of the circuit that listens to the signal and decides how much gain reduction to apply; the audio passes through the gain element, here driven by FETs1.
Controls and the side-chain
The pedal carries Threshold, ratio, attack, release and gain controls1. The ratio runs from very light at 1.5:1 to heavy at 20:1 for generous sustain1.
What sets the Opti-FET apart is its user-selectable side-chain control circuit. It includes an onboard 3-band equalizer that lets you tailor the frequencies on which more or less compression is applied to the audio signal1. There is also an external loop into that side-chain: loop send and return jacks let you place an external graphic equalizer or other outboard processors in the side-chain control circuit when the EQ & LOOP switch is engaged1. In practice, that means you can make the compressor more sensitive to, say, low frequencies without EQing the compressed sound itself.
| Control or feature | What it does |
|---|---|
| Threshold | Sets the level above which compression begins1 |
| Ratio | 1.5:1 (light) to 20:1 (heavy) for generous sustain1 |
| Attack | Sets how quickly compression engages1 |
| Release | Sets how quickly compression lets go1 |
| Gain | Output level1 |
| 3-band EQ | Tailors the side-chain frequencies the compressor responds to1 |
| Loop send/return | External processors in the side-chain, with the EQ & LOOP switch engaged1 |
| ACTIVATE foot switch | Places the compressor in the signal chain or in Direct Bypass mode1 |
Power
An onboard voltage charge pump allows the circuitry to operate at 18 volts, on plus 9 and minus 9 volt rails, from a single 9-volt battery or an AC power adapter of 9 volts or greater1. Pedal of the Day's 2019 review likewise notes it operates from a single 9-volt battery or DC power adapter3.
The Opti-FET Compressor operates from a single 9-volt battery or a DC power adapter3. The maker's announcement gives an MSRP of $245.00 and describes the unit as available12.
Size and availability
The pedal has a small footprint of 4.5 inches by 3.5 inches1. As of May 28, 2010, No Treble reported the Opti-FET available for $245.00 plus shipping and handling2.
What reviewers said
Pedal of the Day's 2019 review found the design gives the audio signal plenty of headroom for active electronic guitars and aggressive playing techniques such as pop and slap, and described a warm tone with excellent noise rejection3.
"This allows the audio signal plenty of headroom from active electronic guitars and aggressive playing techniques (i.e. pop and slap)."
If the Opti-FET interests you, FEA Labs' other compressors take different approaches: the FEA Labs DE-CL, the FEA Labs DE-CL Dual Engine Compressor Limiter, and the FEA Labs DB-CL Dual Band Compressor Limiter. For how optical designs compare with other approaches, see Compressor Pedals.
Videos
Brett Kingman
Brett Kingman
Pedal of the Day
Questions
Does the FEA Labs Opti-FET Compressor run on a battery?
Yes. According to the maker's announcement, an onboard voltage charge pump lets the circuitry run at 18 volts, on plus 9 and minus 9 volt rails, from a single 9-volt battery or an AC power adapter of 9 volts or greater. Pedal of the Day likewise notes it operates from a single 9-volt battery or a DC power adapter.
Is the FEA Labs Opti-FET Compressor true bypass?
The pedal's ACTIVATE foot switch places the compressor in the signal chain or in Direct Bypass mode. The maker's announcement describes this switching arrangement but does not use the phrase true bypass, so the bypass type is best described as Direct Bypass as FEA Labs names it.
What is the side-chain loop on the Opti-FET for?
The loop send and return jacks let you place an external graphic equalizer or other outboard processors in the compressor's side-chain control circuit, which shapes the frequencies the compressor responds to. It works when the EQ & LOOP switch is engaged, alongside the onboard 3-band equalizer.
What compression ratios does the Opti-FET Compressor offer?
The Opti-FET covers ratios from 1.5:1, described as very light, up to 20:1, described as heavy, for generous sustain. Threshold, attack, release and gain controls round out the compression controls.
How big is the FEA Labs Opti-FET Compressor?
FEA Labs describes the Opti-FET as having a small footprint of 4.5 inches by 3.5 inches, which keeps it compact on a pedalboard.
Sources (3)
- FEA Labs Introduces Opti-FET Compressor, Premier Guitar, 2010-05-19
- Gear Watch: FEA Labs Opti-FET Compressor Pedal, No Treble, 2010-05-28
- FEA Labs Opti-FET Compressor, Pedal of the Day, 2019-06-19
