Vintage 1980's Pearl PH-03 Phaser
 
Made In Japan
 
The Phaser creates the sound of a rotary speaker by electronically generating the Doppler Effect. Pearl PH-03 is equipped with a "Manual Control" which creates unique and various tonal colorations of the phasing tones.

Manual sets the position of the effect when the LFO is in the center position or controls the effect when the LFO is switched off
 
Feedback sets the amount of effected signal fed back into the effect (for a stronger effect)
 
Depth controls the depth/amplitude of the modulation (the size of the range in which the effect sweeps)
 
Speed controls the speed/rate of the LFO wave that controls the effect