The JOYO JF-328 is a phaser pedal. It is intended for adding moving phase modulation to a guitar signal.
Key identified features include analogue circuitry.
- Brand: JOYO
- Model: JF-328
- Product type: Phaser Pedals
- Features: Analogue

This is a New JOYO JF-328 Nebulous Phaser Pedal from Joyo, listed in Phaser Pedals on Just Pedals. Read More below.
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JOYO Technology is a Shenzhen music-gear company whose range goes well beyond stompboxes. Its official catalogue covers guitar and bass amplifiers, acoustic and busking amps, effects, power supplies, interfaces, wireless systems and accessories. JOYO also says it develops acoustic-core technology and has applied for utility patents. JustPedals listings include the JF-21 Splinter distortion and JF-319 Green Legend overdrive, alongside mini amps and power adapters. That breadth matters when comparing products under the JOYO name: some are effects, while others support the rest of a guitar or bass rig.
A phaser splits the signal and shifts the phase of one path through a series of all-pass filter stages. When recombined, moving peaks and notches sweep across the spectrum, creating a rounded swirl rather than the evenly spaced comb filtering of a flanger. Stage count, feedback, centre frequency, rate and depth shape the width, resonance and pulse of the sweep.
The signal is shaped by continuously varying electronic circuitry rather than being converted into a digital effect algorithm. Component choice, operating voltage and circuit tolerances influence headroom, noise, clipping texture and the small variations in response between designs.