The JOYO R-31 is a reverb pedal. It is intended for adding space and ambience to a guitar signal.
Key identified features include stereo operation.
- Brand: JOYO
- Model: R-31
- Product type: Reverb Pedals
- Features: Stereo

This is a New JOYO R-31 Para-Verb Reverb Pedal from Joyo, listed in Reverb 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.
Reverb creates the dense pattern of reflections heard after sound enters a physical or imagined space. Room, hall, plate and spring models differ in reflection density, frequency decay and modulation, while ambient algorithms extend or transform the tail beyond natural acoustics. Decay, pre-delay, damping, diffusion and wet/dry balance define the apparent size, surface and distance of that space.
Processes, creates or passes two audio channels. True stereo preserves separate left and right inputs, while mono-to-stereo effects generate spatial differences internally; routing, phase behaviour and whether trails remain stereo determine the resulting image. Some outputs sum to mono when only one socket is connected, which can change level or modulation depth.