The Mosky SUPER OPTO is an analog optical compressor pedal designed for bass guitar. It uses an optical circuit, which Mosky says gives a softer attack and sense than other compressor types, producing smooth, vintage-style compression that tames dynamics without drastically altering the natural sound of the instrument. It sits in the compressor family, alongside Mosky's other models such as the Mosky Dyna Compressor and the Mosky MINI C4 COMPRESSOR.1
Controls
The pedal has four knobs and one footswitch. Each control does a distinct job, and the split between Comp and Sens is the thing most likely to catch out players used to a single-knob compressor1.
| Control | What it does |
|---|---|
| ATTACK | Adjusts the time the compressor takes to respond to an input signal and reduce gain1 |
| COMP | Controls the amount of compression, the ratio1 |
| SENS. | Controls the sensitivity of the compression; the higher the setting, the higher the sensitivity (reversed threshold)1 |
| LEVEL | Used to set the desired output level of the bass compressor1 |
The footswitch is labeled Bass Comp On / Bypass and engages or disengages the effect.1
Because Sens works as a reversed threshold, turning it up makes the compressor react to quieter playing rather than only the loudest notes. Comp then sets how much gain reduction is applied once it does. Attack shapes how quickly that reduction happens, which matters on bass for deciding whether the front of each note stays punchy or is smoothed over. Level brings the compressed signal back up to the volume you want1.
Power and connections
The SUPER OPTO runs on a 9V DC supply with a center-negative plug and draws a maximum of 60mA. Mosky does not include a power supply with the pedal, so you will need your own adapter or a spare output on a pedalboard power supply rated for at least 60mA.1
The pedal has no battery option listed by the maker: the specifications call for a DC 9V supply, which is not included.1
The input impedance is 1.8 Mohms.1
Where it sits among optical compressors
Optical compressors use a light-dependent element to control gain, which is why they tend to react more gently than other compressor designs. Mosky describes the SUPER OPTO's optical circuit as giving a softer attack and sense compared to other compressor types, which is the character bass players usually look for when they want dynamics evened out without the tone changing.1
A related design from another maker is the OVNIFX Smoothie Opto Compressor, another optical compressor pedal.2
Questions
Is the Mosky Super Opto true bypass?
Yes. Mosky lists the Super Opto with true bypass, so when the pedal is off, the signal passes through without the compression circuit loading it. The single footswitch is marked Bass Comp On / Bypass and switches the compressor in and out of the chain.
Does the Mosky Super Opto come with a power supply?
No. Mosky's specifications state the power supply is not included. The pedal needs a 9V DC adapter with a center-negative plug and can draw up to 60mA, so make sure your supply can provide that current on the output you use.
What polarity does the Mosky Super Opto use?
The Super Opto uses a center-negative 9V DC connection, the same standard as most modern pedals. That means it works with typical pedalboard power supplies and daisy-chain adapters, as long as the output can supply up to 60mA.
Is the Mosky Super Opto only for bass?
Mosky designed and markets it as a bass compressor, and the footswitch is labeled Bass Comp. Nothing in the design is exclusive to bass, but the maker's description, controls and naming are all aimed at bass guitar players.
What is the difference between the Comp and Sens controls?
Comp sets the amount of compression, in other words the ratio. Sens sets the sensitivity of the compression: the higher the setting, the higher the sensitivity, which Mosky describes as a reversed threshold. In practice, Sens decides when the compressor starts working and Comp decides how hard it squeezes.
Sources (2)
- SUPER OPTO_Bass Effect Pedal_Products_mosky pedal, moskyaudio
- OVNIFX Smoothie Opto Compressor, Delicious Audio, 2019-03-22
