In a post by harrisonarchive on Instagram, George Harrison is shown with a Maestro PS-1A Phase Shifter, highlighting its use during the Extra Texture promotional period.

Jones also notably utilised effects units for his keyboard playing in Led Zeppelin, particularly favouring a Maestro Phase Shifter to emulate various rotary speaker sounds, which can be sitting atop of his keyboard rig in various images from 1973-1979.

Which guitars did you use on Rush's first LP, Rush?

I used the 335 and a rented Rickenbacker 12-string. That's it for guitars. I played them through my Marshall 50 with a 4-12 cabinet, and I used a Maestro phase shifter, a Cry Baby wah-wah, and an Echoplex.

Many of your songs have either a phased or a chorus effect.

I like both sounds. Ever since A Farewell To Kings I've used a Roland Boss Chorus. I liked the Maestro phaser as opposed to, say, MXR Phase 90s or 100s; it was a little more subtle than the MXR phase lines. But after I heard the Chorus, I loved it and decided to incorporate it into my music. Hemispheres and Permanent Waves have a lot of Chorus -almost every song has Chorus, since with a three-piece band it tends to widen the guitar sound.

From the GuitarPlayer article "Depeche Mode's Martin Gore," Gore says, "I also got quite a few Maestro pedals—a PS-1 Phase Shifter, an MPS-1 Mini- Phase, and an FZ-1A Fuzz-Tone—as well as Ross compression and distortion pedals that I used a lot, too."

At 12:16 , he starts naming all the equipment he's got at home... about four or 5 seconds later he says he has a Flanger, as well as a Phase Shifter at his place.

At the 7:35 in this video of Daryl Hall and The Doors playing Roadhouse Blues for Daryl’s house, you can clearly see Ray Manzarek using the Maestro PS-1A Phase Shifter, positioned on top of his Vox Continental keyboard.

On his twitter account, he posted this photo with the pedal given to him by Joe Banamasa.

Jennings was famous for his use of this phaser, particularly on Dreaming My Dreams, as stated by studio engineer Kyle Lehning in this April 27, 2010 Mix Online interview.

On the whole, the Dreaming My Dreams sessions were cut live. (...) "We had a lot of extra instruments around the studio, as well," Lehning continues. "[Waylon] would actually play my electric 12-string from time to time and run it through his Maestro Phaser—though mostly he would play his old leather Telecaster."

Jennings' PS-1A was sold on eBay on October 23, 2018 for $18k.

Waylon Jennings 1970's Maestro PS 1A Phase Shifter with foot switch, this was used live and on recordings. Think the "Dukes of Hazard", "Mammas Don't let your babies grow up to cowboys" thats what this effect is. It works and sounds good. This was obtained from Waylon Jennings personal collection. Comes with documentation. Please see auctions for more Waylon Jennings items.

Used on 3+3, particularly on "That Lady". There are multiple sources:

The Big Muff Users section of Kit Rae's Big Muff Page

A year after that, the funk/soul scene was hammered with the famous solo from the Isley Brothers hit, (Who's) That Lady, played to perfection by Ernie Isley. There are various accounts of what was actually used in the studio, some sources state it was recorded directly into the mixing board with a Strat and Roger Mayer Octavia, but other sources state it was a Big Muff and Maestro Phase Shifter, and Ernie also used a Big Muff and a Maestro Phase Shifter when playing it live throughout the 1970's (the modulation on the record actually sounds identical to the Maestro too).

(the signal) goes through a Cry Baby wah-wah, a Big Muff fuzz, a Maestro Phase Shifter, and an Octavia made by Roger Mayer. - Ernie isley from Guitar Player, September 1981

“On ‘That Lady’ there was a Big Muff, a Maestro Phase Shifter, and a Fender Twin. That was pretty much it.” - Ernie isley from Vintage Guitar magazine, February 2018

Guitar.com, June 18, 2020

“We were working with the same engineers Stevie Wonder was using on what would become Innervisions,” Ernie begins. “We were working on the record that became 3+3. There was a fuzz box and a phase shifter by Maestro, and that was pretty much it. We took it from there. It was fun.”

Stompbox: 100 Pedals of the World's Greatest Guitarists by Elion Paz

• Reported by All Arts on November 30, 2020.

“Stompbox” features actual pedals from celebrated guitarists past and present, including Hendrix’s legendary Fuzz Face, the Maestro PS-1A Phase Shifter used by Ernie Isley, and Marc Bolan’s Vox Clyde McCoy wah-wah. A photo of each pedal is set next to an interview with its owner, and the book broken into sections about history, innovation, design and use cases.

• Pedal 40, as can be seen in the quick browse video at 0:19.

I plugged in, and I discovered the "That Lady" sound right there in Guitar Center. Nobody even turned around. But I knew that I'd discovered a new sound.

Terry Kath used a Maestro PS-1A Phase Shifter, as documented on The Terry Kath Experience website under the "TK's Gear" section.

Visible on top of his Echoplex

On June 5th, John Foxx will be taking his group The Maths to the Roundhouse in Chalk Farm London for a one-off performance of his classic album Metamatic. Now, after our feature on Benge's synths was such a hit with you lot, we thought that some of you might like to get warm under the collar and quivery of the finger tip to learn what John Foxx will be packing in the back of the van for the Roundhouse show - please check out the mouthwatering list below, and have a look at some John Foxx & The Maths on YouTube while you're at it. Find out more about this incredible event (which also features a DJ set by Gary Numan and Ade Fenton) at the Roundhouse website. John Foxx'Metatronic best-of is out now.

Synthesizers:

ARP Odyssey x 2, ARP Sequencers x 2, Crumar Multiman, EDP Wasp, Korg MonoPoly, Korg 700, Logan String Machine, Moog Mini x 2, Moog Modular plus Sequencers, Moog Opus 3, Roland Modular System 100m x 10 Modules, Roland SH2, Roland SH-101, Roland Juno 60, Sequential Circuits Multitrack

Drum machines:

Amdek Percussion Synthesiser, Boss Dr Rhythm, Linn Drum, Klone Drum, Roland CR78, Roland TR808

Effects & Processors:

Boss Chorus, Boss Flanger, Boss Phaser, Electro Harmonix electric mistress Flanger, Furman Spring Reverb, Ibanez AD80 Analog Delay, Maestro PS-1 Phase Shifter, Mu-tron Phasor, MXR Phase 100, Roland Space echo RE-201

Other Equipment

Tascam & Revox Analogue Reel to Reel Tape Machines