Korg PX4D Processor Since its introduction, the Pandora series has been acclaimed by guitarists and bassists for its high-quality sound, versatile functionality, and superb user interface - all in an amazingly compact package. And now, the new PX4D joins the series. The PX4D combines both guitar and bass functionality into a single unit, and delivers a major leap in functionality as well. Its comprehensive range of sounds includes vintage amps and a wide range of cabinets, as well as effects ranging from classic to distinctively unique. The PX4D is a great choice not only for practicing, but for any situation that demands great guitar or bass sound, including recording and live performance.