In the '70s, effect manufacturers introduced phase pedals attempting to recreate the vibey tape flanging sounds heard on psychedelic records. Unlike flangers—which use delay to emulate this sound—phasers use an LFO wave sent through all-pass filters to produce their chewy, modulated sound. Ultimately, these pedals add a totally different and new palette of sounds to explore. Since then, phase shifters have been an essential modulation sound on many guitarists' pedalboards.
Released in the United States under the Ibanez brand, the Maxon PT-909 was a follow up to the earlier one-knob PT-999. While the earlier model only has one control to set the rate of the phase effect, the PT-909 adds "Feedback" and "Width" controls. Feedback adjusts the amount of the effected signal that is sent back through the effect, so it increases the overall intensity of the effect. Width controls the depth/amplitude of the modulation—that is, the size of the range in which the effect sweeps. These two additional knobs make the PT-909 more flexible than the earlier models.
This Maxon PT-909 Phase Tone dates from 1979, and it is the earlier rectangle-box version of the pedal. Because Ibanez had the distribution rights, the Maxon-branded units are somewhat rare in the United States. This Maxon PT-909 is in nice shape for its age, too. There are some expected paint chips and cosmetic wear, but it still has all of its original components. A previous owner added velcro to the bottom, and the serial number is worn to be illegible. It is also missing one screw on the bottom.
This 1979 Maxon PT-909 functions 100% exactly as it should, and it sounds fantastic. It covers all of the classic '70s phase shifter sound, and the controls do lend a wide range of versatility. It's amazing how great these pedals sound 42 years ago!