Roland AP-7 Jet Phaser

This vintage pedal is very clean and sounds amazing. The Jet Phaser was a favourite of Larry Graham. Here is a cool video of him showing off what it can do.



It sounds equally killer on guitar as well.

Best described via Tonefrenzy:

"The Roland "Jet Phaser" is a large, light brown effects pedal, about the size, and shape of their AP-5, "Phase Five" pedal, or Roland CE-1 "Chorus Ensemble". Roland engineered the Jet Phaser to feature a range of combined Fuzz/ Phase effects. When the "Jet" function is selected, you'd have to fight the pedal's nature, to feature a subtle sound quality. Hint: The Jet reference is all-telling, in this context. There's a wide range of phaser effects available on their own, but Jet flavored distortion was designed to be front & center. You can adjust it to be more defined, or distinctly enormous. 
Once selected, the phase effect always stays on, that's the phaser part of the effect. (The Jet can be turned on and off at will). The phaser's settings are also switchable, between fast & slow speeds; these transition slowly, as if being accomplished physically, emulating Leslie rotating speakers, used with Hammond Organs. It's clearly more musical to have this option on board: a much more "alive" quality. Instant on/off of many similar pedals, insults the quality of their modulating effects. 
Combining instant on & off, with robotically even effect cycles, can degrade some beautiful musical moments. Such embarrassingly mechanical embellishments, "really bite", in the sentiment rich music they're used for. It distracts from the feeling, an artist is working to project. Like a magician dropping the cards; pushed up his sleeve, just after he made them "disappear". It breaks the spell...yes? The phasing on Roland's Jet Phaser, and their Ap-5 "Phase Five", both have very real sounding speed transitions. 
The Jet Phaser is also one of those effects that's very distinctly voiced. Particularly when doing it's Jet thing, you're bound to think of the late Seventie's, through early/mid eighties, and so is your audience."