Numerous high-quality effects using REMS modeling technology are built in. : Features 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 electric-acoustic guitars. : A notch effect setting provides control against acoustic feedback - or howling. There's also an auto notch function that automatically detects the feedback point. : 100 programs provided - 50 preset and 50 user programmable. : The PX4A's 100 built-in rhythm patterns cover a broad range of styles that include rock, jazz, funk, blues and dance music. The PCM sounds used in these patterns produce realistic accompaniments that are fun to play along with. There are even bass patterns that let you specify the key chord, so you can practice any style of music while listening to a full rhythm and bass line. : Offers up to eight effects simultaneously. : Knob-based interface for quick and intuitive editing. : The Phrase Trainer function offers a great way to learn by ear or to practice soloing. : You can connect a CD player or another external audio source to the PX4A's Aux In jack, and use the Key Transpose function to change the pitch of the song upward or downward by as much as one octave : AUX IN jack lets you play along with external CD, MD, or MP3 audio sources. : The built-in Auto Chromatic Tuner also provides a Mute function for silent tuning. : Semi-transparent LCD illuminates the characters in inverse video when backlit. : Two-way power supply lets you use either batteries or separately sold AC ...