The Mosky OTA PHASER is a hand-built analog phaser stompbox from Mosky, part of the maker's M-Series range. It puts a four-mode phaser in a compact pedal, with a Rate control for the sweep speed, a Depth control that works as a dry/wet mixer, and a Tone button for refining the effect.1
What the OTA Phaser does
A phaser splits your guitar's signal, shifts the phase of part of it, and sweeps that shifted sound against the original to create the familiar moving, whooshing effect. The OTA PHASER does this with an analog circuit, according to RockBoard's PedalPedia listing.2
The pedal's controls cover the essentials of the effect:
| Control | What it does |
|---|---|
| Mode selector | 4-mode selection knob for choosing between phaser settings1 |
| Rate | Sweeps through the range of LFO speeds in both modes, from subtle to extreme phasing effects12 |
| Depth | Functions as a dry/wet mixer, dialing in the balance between the original signal and the phased sound2 |
| Tone | A button to further refine the phasing effect to suit your playing style2 |
RockBoard describes the pedal as "a versatile stompbox," noting that the Rate control "allows for sweeping LFO speeds, ranging from subtle to extreme phasing effects."2
Power, bypass and size
The OTA PHASER runs on a 9V DC supply with the center of the plug negative, the standard polarity for most pedal power supplies. Mosky lists the pedal as True Bypass, so the phaser circuit is out of the signal path when the pedal is off.1
Use a 9V DC center-negative supply. An AC adapter or a supply with the wrong polarity can damage the pedal.1
The pedal is small and light, which suits a crowded board:
- Weight: 300 g1
Videos
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Questions
Is the Mosky OTA Phaser true bypass?
Yes. Mosky's product page lists the OTA PHASER as True Bypass, so when the pedal is off, your guitar's signal passes through without the phaser circuit in the way. That matters on a pedalboard where several pedals sit between the guitar and the amp, since buffered stages can add up over a long chain.
What power supply does the Mosky OTA Phaser need?
The OTA PHASER runs on a 9V DC power supply with the center of the plug negative, which is the standard polarity used by most pedal power supplies. Use a regulated 9V DC supply rather than an AC adapter, and check that any daisy-chain or isolated supply you use delivers 9V DC center negative.
Is the Mosky OTA Phaser analog or digital?
RockBoard's PedalPedia lists the circuit type of the Mosky OTA Phaser as analog. Analog phasers use operational transconductance amplifier stages to shift the phase of the signal, which is where the pedal's name comes from.
What does the Depth knob do on the Mosky OTA Phaser?
On the OTA PHASER, the Depth control works as a dry/wet mixer. It sets the balance between your original, unprocessed signal and the phased signal, so you can dial in anything from a faint sweep behind your tone to a full, pronounced phasing effect.
How many modes does the Mosky OTA Phaser have?
The pedal has a four-mode selection knob, giving four phaser settings to choose from. Combined with the Rate control, which sweeps the LFO speed in both modes, and the Tone button, it covers a range of phasing sounds from subtle to extreme.
How big is the Mosky OTA Phaser?
Mosky lists a packing size of 147 mm wide by 78 mm deep by 7 mm high, and the pedal weighs 300 g. That compact footprint and light weight make it easy to fit onto a crowded pedalboard.
Sources (2)
- OTA PHASER_M-SERIES_Products_mosky pedal, moskyaudio.com
- OTA Phaser by Mosky, RockBoard PedalPedia, 2026