The Korg Pandora PX4A Acoustic Personal Multi-Effects Processor transforms sterile-sounding piezo output into deep, warm acoustic tone for great sound whether practicing, recording, or playing live. 82 effects include REMS modeling of the resonance and vibrational character of great acoustic guitars. Vintage and modern instruments have been modelled with painstaking detail to produce realistic, rich, and natural sound. Models also include a resonator guitar, a banjo, 12-string, and a nylon-string guitar. There's even one that simulates the drone tones of ethnic instruments such as a tambura.

The Korg PX4A also includes a full range of standard effects such as compressor, limiter, echo, delay, reverb, and chorus.

The Korg PX4A has 50 presets and 50 user programs that allow up to 8 simultaneous effects per program. Also included is a notch filter effect for protection against feedback, plus an auto notch function that automatically detects the feedback point during performance.