Chorus D is an audio unit effect inspired by a well-loved classic chorus stomp-box. HOW IS IT DIFFERENT FROM OTHER CHORUS EFFECTS? It's more subtle. It has a stereo pair of pitch-shifters, one shifts up and the other down. Every few seconds, the two pitch shifters trade places: the high one goes low and the low one goes high. Unlike most other chorus effects, the pitch-shift amounts stay constant rather than oscillating up and down. For that reason, you don't hear the wavy pitch sound that other chorus effects make. At low settings, you can put it on a track to widen the stereo image or thicken up the sound and listeners may not be able to identify that they are hearing a chorus effect. WHY ONLY SIX BUTTONS? The original hardware that inspired this design had only four buttons and four presets, one for each button.* The simplicity of the controls is one of the reasons the effect was so well-liked: all four presets sounded great. With six buttons you get tones ranging from very subtle to clearly audible, and all of them are tasteful and useful. This effect makes only one type of sound but it's a unique sound that you don't get from other chorus effects. IS THIS AN EXACT CIRCUIT MODEL OF THE ORIGINAL HARDWARE EFFECT? No. We listened to the original and studied its design but then we built an effect to please our own ears. It sounds similar to the original but the design is unique. ************************************ Note: this is an audio unit plugin. It does not process audio as a standalone app. *Later on customers figured out that they could get some other settings by pressing two buttons simultaneously or forcing all the buttons off. We are using six buttons to get wider variety of sounds rather than expecting customers to discover those secret features of the original hardware.