Brand
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.
Category
Fuzz drives the signal into extreme clipping, often flattening the waveform and generating a thick spectrum of harmonics. Transistor type, bias, input loading and tone filtering create markedly different responses, from loose and velvety to gated, spluttering or octave-rich. Some circuits interact strongly with pickup impedance and guitar volume, while others include buffers or blends for a more consistent response.
Tags
Clips the waveform firmly and adds a dense series of harmonics with compression and sustain. The clipping devices, gain stages and tone filters determine whether the result is tight, smooth, mid-focused, scooped, grainy or deliberately abrasive.
Uses moderate clipping and gain-dependent compression to add harmonics while retaining much of the original note contour. Bass filtering, mid emphasis, clipping symmetry and available headroom decide whether it sounds open and amplifier-like, tightly focused or heavily saturated.