Seldom before has an innocent-looking pedal offered such devilish delights.
Combining a ferocious fuzz circuit with remarkably powerful pitch-shifting capabilities, Keeley’s new Octa Psi pedal makes it easy to blow your mind … and have a ton of fun in the process.
It’s capable of creating pleasing and/or demented intervals, subtle harmonizing, expansive octaves up and down, and swooping pitch changes—all turbocharged by one of the gnarliest fuzzes this side of Armageddon.
Simply Psychoactive ... By Intent
If you’ve ever craved a user-friendly freakout, this is it. With just five knobs, two 3-way toggle switches, and a pair of footswitches—as well as an expression pedal input—the Octa Psi presents a comfortable, inviting portal to a universe of crazy sonic exploration.
That’s exactly what Robert Keeley intended from the moment he started designing the Octa Psi.
“The finished pedal is true to the original idea that I had in November 2021,” Keeley says. “I wanted it to have a high-gain vintage Muff, all-analog and all-transistor, going into an octave pitch shifter—something in the neighborhood of a Pitch Fork or POG. And then when I added the expression pedal function, it could resemble a whammy.”
Ah yes, the expression pedal input. Linking the Octa Psi with a standard expression pedal opens the door to a whole new dimension of pitch shifting mayhem. Rest assured, you don’t have to use an expression pedal to derive crazy fun from the Octa Psi. But it sure helps.
With all of the pedal’s deep functionality, Keeley felt that simplicity would be a key factor in broadening its appeal, starting with this elemental item: “From the get-go I wanted it to have order switching, allowing the fuzz feeding the pitch shifter or vice versa, because it gives you two distinctly different sounds if you have pitch going before or after the fuzz. And it had to be pretty effortless for the player to switch the order on the fly. And I wanted it to be easy to switch between using it either as a harmonizer or as an all-wet octave-down thing.” That desire for ease-of-use, even in the middle of a live gig, drove the design of the pedal’s controls and functions.
“I wanted to come up with something that Jack White, Steve Vai, or Frank Zappa would have fun with.”
It Ain't Easy to Create Easiness
The Octa Psi exemplifies an old adage: Sometimes a simple solution can be the most difficult to achieve. “I knew this was going to be a challenging project,” Keeley admits. “It’s very tough to combine a high-gain, full-analog distortion with a DSP [digital signal processing] section in one box. It took a long time to get the switching just right. It was particularly difficult because the Octa Psi’s analog and DSP sections are so intimately entwined. You can’t have gaps in the audio when you’re switching back and forth. Those kinds of complications drove us crazy.
“We also addressed a lot of issues that have raised concerns about other products on the market. The Octa Psi is a true-bypass pitch shifter, and it has our killer buffer system as well. There’s nothing else out there like this, so we had to figure it all out for ourselves.“
An essential challenge: voicing the fuzz so that it would sound great as a standalone effect, while also playing nicely with the Octa Psi’s harmonizer functions. “You would think that the fuzz was easy, but it was actually one of the last things we ironed out,” Keeley notes. “I had to ask myself, ‘Do I want this to be a bass-y fuzz?’ Probably not, since the pitch shifter can add octave down. But it’s got to be an amazing sounding fuzz if I want people to consider buying it. It has to sound great when compared to any Big Muff, and it has to effortlessly pair with a DSP section. So, getting the fuzz just right turned out to be the hardest part!”
The pedal design process also encountered some last-minute wrinkles. “The ramping and momentary switching capability was the last big feature that was added. That ramping function is like having an onboard expression pedal. We talked about it in the beginning of the process with Sarah Lipstate [also known as the artist Noveller], when Aaron Pierce [a key member on the Keeley team] was working on the initial concept. Later, Michael Kaye—the guitar tech for Pete Townsend and Trey Anastasio—asked, ‘Does it have momentary switching?’ and I was like, ‘Oh crap, I forgot about that!’” Keeley laughs.
The How-To Guide for Octa Psi's Hidden Features
For all of its readily accessible capabilities, the Octa Psi boasts several essential features that can only be accessed by using more than a single knob or switch. To unlock these features, it helps to have a few simple, specific instructions. For this reason, Keeley has included a brisk, handy primer on the back of each pedal. The Octa Psi’s key “hidden features” include:
- EFFECT ORDER: You can instantly switch the effect order by simultaneously holding the octave and fuzz footswitches.
- WET/DRY SELECTION: Double-click the blend control knob for switching between wet/dry blending or wet-only.
- MOMENTARY/LATCHING OPTION: Press and hold the fuzz footswitch to choose between momentary or latching operation. This is crucial if you plan on using the Octa Psi’s adventurous pitch shift ramping capability: the output signal begins with the initial note(s) you’re playing, and then veers up or down to the effected pitch. The ramp speed—i.e. how quickly this veering effect lasts—is controlled by….
- RAMP SPEED: If you’re using pitch shifting in the momentary mode, you can adjust the ramp speed by pressing and holding the octave footswitch down, then adjusting the blend knob control.
Part of an Ongoing Evolution
The Octa Psi underscores the continuing evolution of Keeley’s product line. In particular, it benefits from a pair of preceding Keeley devices: the I Get Around Rotary Simulator pedal and California Girls Twelve String Simulator—two pedals that were released in summer 2024 as exclusive offerings for the U.S. retailer Sweetwater, timed to coincide with The Beach Boys documentary on Disney+.
“That Beach Boys project did so much to help the DSP side of the Octa Psi,” says Keeley. “I got audio analyzers in so I could study the signals. We found out that we had to make our power supplies better because of the Beach Boys pedals, and that revolutionized our design. Everything that comes out since the Beach Boys pedals is going to sound even better. Plus, it was a lot of fun working with Sweetwater and JHS Pedals.”
Interestingly, for the Octa Psi project, the Keeley design team did not rely on much input from the company’s long list of affiliated artists. “I didn’t really have an artist that is a pitch/fuzz guru, so I had to keep it pretty much to ourselves. I knew that it had to be very musical—as musical as we could get it. And thankfully we have a team that can make this happen.”
The Keeley product development squad includes electrical engineer Craighton Hale, programmer Aaron Tackett, and Aaron Pierce—the “golden ears” member of the design group who helps analyze the sounds. “I’m just one part of the team of engineers that help make the products come to life,” Keeley notes.
Fun for Everyone
In the end, Keeley hopes that the Octa Psi pedal finds new and unconventional uses in the real world. “I wanted to come up with something that Jack White, Steve Vai, or Frank Zappa would have fun with—something that does all the crazy pitch-shifting with a purpose. And I’m hoping that musicians of all types will be attracted to this. People who want to distort their drums or bass or synth, and then start taking advantage of the pitch shifting. It’s almost like you get a great fuzz with the pitch shifter for free. On the other hand, I wouldn’t be surprised if some people use just the pitch shifter, if they’re not a fuzz maniac. You can get a lot of fun out of it without an expression pedal.”
Whether you’re a brazen sonic adventurer, or simply looking for a great-sounding dual function fuzz/harmonizer pedal, the Octa Psi offers a galaxy of tones for your arsenal.
The giveaways keep going! Enter Stompboxtober Day 25 for your chance to win today’s pedal from SoloDallas!
The Schaffer Replica® - BASS-X
After introducing the Schaffer Replica Storm low end legends like Rudy Sarzo, Billy Sheehan, and Pino Paladino discovered it to be equally amazing on bass. Based upon their input we made a few minor changes to this beloved circuit to make it more conducive to higher amplitude and lower frequencies. To our loyal bassists who have waited so patiently, we proudly introduce The Schaffer Replica - BASS-X.
Vintage-style reverb, tremolo, and vibrato sounds abound in a 3-in-1 stomp that might be the only box you need.
Here’s part two of our look under the hood of the funky rhythm guitar master’s signature 6-string.
Hello and welcome back to Mod Garage. In this edition, we’re continuing our journey through the Fender Cory Wong Stratocaster wiring, bringing it all together.In the previous installment, the last feature on the funky 6-stringer’s signature axe that we discussed was the master volume pot and the corresponding treble-bleed circuit. Now, let’s continue with this guitar’s very special configuration of the tone pots.
Tone pot with Fender Greasebucket tone system:
This 250k tone pot is a standard CTS pot with a 90/10 audio taper found in all U.S.-built Fender guitars. The Cory Wong guitar uses the Fender Greasebucket system, which is added to the pot as a ready-to-solder PCB. The Greasebucket PCB is also available individually from Fender (part #7713546000), though you can use conventional electronic parts for this.
Fender introduced this feature in 2005 on some of the Highway One models and some assorted Custom Shop Strats. The Greasebucket name (which is a registered Fender trademark, by the way) is my favorite of Fender’s marketing names, but don’t let it fool you: Your tone will get cleaner with this modification, not greasy and dirty.
According to Fender, the Greasebucket tone circuit reduces high frequencies without adding bass as the tone knob is turned down. Don’t let that description confuse you. A standard Strat tone control does not add any bass frequencies! As you already know, with a passive system you can’t add anything that isn’t already there. You can reshape the tone by deemphasizing certain frequencies and making others more prominent. Removing highs makes lows more apparent and vice versa. In addition, the use of inductors (which is how a passive pickup behaves in a guitar circuit) and capacitors can create resonant peaks and valleys (band-passes and notches), further coloring the overall tone.
Cory Wong bringing the funk onstage.
This type of band-pass filter only allows certain frequencies to pass through, while others are blocked. The standard tone circuit in a Strat is called a variable low-pass filter (or a treble-cut filter), which only allows the low frequencies to pass through while the high frequencies get sent to ground via the tone cap.
The Greasebucket’s band-pass filter is a combination of a high-pass and a low-pass filter. This is supposed to cut high frequencies without “adding” bass, which has mostly to do with the resistor in series with the pot. That resistor means the control will never get to zero. You can get a similar effect by simply not turning the Strat’s standard tone control all the way down. (The additional cap on the wiper of the Greasebucket circuit complicates things a bit, though; together with the pickups it forms an RLC circuit, but I really don’t want to get into that here.)
The standard Fender Greasebucket tone system is used in the Cory Wong Strat, which includes a 0.1 μF cap and a 0.022 uF cap, along with a 4.7k-ohm resistor in series. These are the values used on the PCB, and without the PCB it looks like the illustration at the top of this column.
Push-push tone pot with preset overwriting function:
The lower tone pot assigned to the bridge pickup is a 250k audio push-push pot with a DPDT switch. The switch is used to engage a preset sound by overwriting the 5-way pickup-selector switch, no matter what switching position it is in. The preset functionality has a very long tradition in the house of Fender, dating back to the early ’50s, when Leo Fender designed a preset bass sound on position 3 (where the typical neck position is on a modern guitar) of the Broadcaster (and later the Telecaster) circuit. Wong loves the middle-and-neck-in-parallel pickup combination, so that’s the preset sound his push-push tone pot is wired for.
The neck pickup has a dedicated tone control while the middle pickup doesn’t, which is also another interesting feature. This means that when you hit the push-push switch, you will engage the neck and middle pickup together in parallel, no matter what you have dialed in on the 5-way switch. Hit the push-push switch again, and the 5-way switch is back to its normal functionality. Instead of a push-push pot, you can naturally use a push-pull pot or a DPDT toggle switch in combination with a normal 250k audio pot.
Here we go for the wiring. For a much clearer visualization, I used the international symbol for ground wherever possible instead of drawing another black wire, because we already have a ton of crossing wires in this drawing. I also simplified the treble-bleed circuit to keep things clearer; you’ll find the architecture of it with the correct values in the previous column.
Cory Wong Strat wiring
Courtesy of singlecoil.com
Wow, this really is a personalized signature guitar down to the bone, and Wong used his opportunity to create a unique instrument. Often, signature instruments deliver custom colors or very small aesthetic or functional details, so the Cory Wong Stratocaster really stands out.
That’s it! In our next column, we will continue our Stratocaster journey in the 70th year of this guitar by having a look at the famous Rory Gallagher Stratocaster, so stay tuned!
Until then ... keep on modding!
The Keeley ZOMA combines two of iconic amp effects—tremolo and reverb—into one pedal.
Key Features of the ZOMA
● Intuitive Control Layout: Three large knobs give you full control over Reverb Level, Tremolo Rate,and Depth
● Easy Access to Alternate Controls: Adjust Reverb Decay, Reverb Tone, and Tremolo Volume withsimple alt-controls.
● Instant Effect Order Switching: Customize your signal path. Position tremolos after reverb for avintage, black-panel tone or place harmonic tremolo before reverb for a dirty, swampy sound.
● True Bypass or Buffered Trails: Choose the setting that best suits your rig.
Three Reverb and Tremolo Modes:
● SS – Spring Reverb & Sine Tremolo: Classic spring reverb paired with a sine wave tremolo for that timelessblack-panel amp tone.
● PH – Plate Reverb & Harmonic Tremolo: Smooth, bright plate reverb combined with swampy harmonictremolo.
● PV – Plate Reverb & Pitch Vibrato: Achieve a vocal-like vibrato with ethereal plate reverb.
Reverb: Sounds & Controls
● Spring Reverb: Authentic tube amp spring reverb that captures every detail of vintage sound.
● Plate Reverb: Bright and smooth, recreating the lush tones of vibrating metal plates.
● Reverb Decay: Adjust the decay time using the REVERB/ALT SWITCH while turning the Level knob.
● Reverb Tone: Modify the tone of your reverb using the REVERB/ALT SWITCH while turning the Rate knob.
Tremolo: Sounds & Controls
● Sine Wave/Volume Tremolo: Adjusts the volume of the signal up and down with smooth sine wavemodulation.
● Harmonic Tremolo: Replicates classic tube-amp harmonic tremolo, creating a phaser-like effect withphase-split filtering.
● Pitch Vibrato: Delivers pitch bending effects that let you control how far and how fast notes shift.
● Alt-Control Tremolo Boost Volume: Adjust the boost volume by holding the REVERB/ALT footswitch whileturning the Depth knob.
The ZOMA is built with artfully designed circuitry and housed in a proprietary angled aluminum enclosure, ensuring both simplicity and durability. Like all Keeley pedals, it’s proudly designed and manufactured in the USA.
ZOMA Stereo Reverb and Tremolo
The first sound effects built into amplifiers were tremolo and reverb. Keeley’s legendary reverbs are paired with their sultry, vocal-like tremolos to give you an unreal sonic experience.