The PX4D packs both guitar and bass functionality into a single unit (a first in the history of the Pandora series). It contains a total of 158 effect types ranging from realistic amp sounds - including high-quality cabinets - to sophisticated effects and lets you use up to seven effects simultaneously. One special PX4D function is a Bass Canceller that removes the sound of the bass from an external audio source.
The PX4D provides 200 programs (100 preset / 100 user)
The PX4A is designed especially for electric-acoustic guitar. It contains a total of 82 effect types, including mic' and body effects that simulate natural acoustic resonance and mic'ing, as well as effects that have been optimized for electro-acoustic guitars. You can use up to eight effects simultaneously. One extremely practical feature of the PX4A is that it provides a notch effect that is particularly effective against acoustic feedback (howling). There's also an auto notch function that automatically detects the feedback point.
the PX4A provides 100 programs (50 preset / 50 user).
Main Features Common to Both