- controls the speed/rate of the LFO wave that controls the effect
- controls the depth/amplitude of the modulation (the size of the range in which the effect sweeps).
1977 - PH-1 Phaser
The first phaser effects were designed to emulate the swirling sounds of rotating speaker systems. The PH-1 Phaser, however, allowed musicians to get some very unique phasing tones beyond anything that had come before it. Quiet operation and unsurpassed reliability made it a very popular effect.