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
Compression reduces the difference between louder and quieter parts of the signal. It can restrain peaks, lift decaying notes and make picking feel more even, but strong settings also change the attack and add audible sustain or pumping. Threshold, ratio, attack, release and blend determine when gain reduction begins, how firmly it acts and how much natural transient detail remains.
Tags
Raises signal level and may also reshape the frequency balance before the next stage. A clean boost preserves the waveform until headroom is exceeded, while coloured designs emphasise particular frequencies or add mild clipping that changes how later gain stages respond.
Raises or lowers defined frequency regions. Fixed-band graphic controls provide direct visual shaping, while parametric controls vary centre frequency and bandwidth; the available range and filter width determine whether the change is broad tonal balance or narrow corrective filtering.
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.