The Boss PH-1 is a 4-stage phaser covering a 16 second to 100 msec range. It was released together with the OD-1 and SP-1 as the first three Boss compact pedals. The phaser attempts to emulate a rotating speaker like the Hammond Leslie cabinets that was very popular among organ players in the 1970s. With the added settings on an electronic version users are able to dial in tones that a real rotating speaker could never achieve.