The Quattro, like the name suggests, is a four mode delay: COPY (Digital Delay) / ANALOG / MODULATION / FILTERED. The maximum is exactly 958,3 ms, for those of you who always dreamed of that magic 958,3 ms delay sound (weird, we know !) COPY is the standard digital delay sound, where the echo sounds as close to the original as possible. ANALOG sounds like the classic BBD (Bucket Brigade Delay) effect, where the delay sounds degraded with less high frequencies and a lot more smear in the sound.