
The second installment in the company’s new line of overdrives—and the latest collaboration with guitarist Andy Timmons—shows evolution on multiple fronts.
Asked to describe his new Muse Driver pedal, Robert Keeley keeps coming back to a single theme: versatility.
Based on Keeley’s much-admired Blues Driver-inspired circuit, and designed in collaboration with Andy Timmons, the Muse Driver features two different selectable overdrive voices and a pair of tone stack options. The result: a highly flexible and responsive pedal that’s likely to appeal to a broad range of players.
Keeley even came up with a new phrase, calling the pedal a “drive workstation” as a shorthand way to convey the Muse Driver’s versatility. “I was trying to say that it could do everything from a clean boost to distortion and overdrive and even fuzz,” he says. “The drive control is so dynamic that it offers incredible range.” That phrase wasn’t meant to be boastful; it simply seems like an accurate, compact way of getting the point across. “It becomes a workstation because you can get so much out of it. In my mind it qualifies as a workstation of drive pedals.”
Brandishing its myriad tones, the Muse Driver, with a street price of $199, is the second pedal in Keeley’s new line of sleek, seductive overdrives. It follows the Noble Screamer, a potent mash-up of the beloved Tube Screamer and Nobels ODR-1, which Keeley released in late 2023 to broad acclaim. The Muse Driver continues the Noble Screamer’s form factor, with dual toggle switches for modifying the circuit, and points the way for three more overdrives coming in 2024. (More on that shortly).
Tapping Into Timmons' Tone
Importantly, the Muse Driver represents the latest chapter in Keeley’s ongoing collaboration with Andy Timmons (known for his solo work and touring/recording with Danger Danger, Olivia Newton-John, Kip Winger, and many more). They first began working together in early 2020, when Timmons and Keeley teamed up on the wildly successful Halo dual echo pedal, and the creative partnership continued with the 2023 release of Timmons’ signature Keeley Super AT MOD overdrive.
For their newest collaboration, Keeley and Timmons once again used a modified Blues Driver circuit as the foundation of the tone. But this time around, the goal was to provide even more sonic options—enough to satisfy Timmons’ most expansive creative urges.
“The Muse Driver name is a play on words with the Blues Driver,” Timmons notes, “and Muse Driver really is an accurate term for the pedal because it reflects how inspiring it is. The core of both the Super AT Mod pedal and the Muse Driver were designed to capture the modded Blues Driver, but could really get those notes to speak and articulate in a certain way. The circuit gives me that clarity on the top end. With the Muse Driver pedal I feel like I’ve truly arrived. I can plug this into any nice, flat amp. It retains the clear top end and it speaks well. And it has a surprising amount of gain, that’s really usable. It doesn’t get too tubby or floppy in the low end. It’s very carveable. I started the search with the Keeley Blues Driver, and now I feel that it’s really there.”
“The gloves come off when we’re working with Andy,” Keeley adds with a laugh. “We’ll try almost anything to create something that’s going to be inspiring for him. I know my job is done when he gets excited and starts writing musical parts with it.”
Keeley Electronics - Muse Driver Overdrive and Distortion with Andy Timmons
Cracking the Diode Code
But it wasn’t easy getting there. “We had three different sessions for the Muse Driver,” says Timmons. “The key was Aaron Pierce [a core member of the Keeley creative team], Robert, and I being in the same room. At one point we thought we were really close,” Timmons admits, “and I’m driving back to Oklahoma. About an hour into the drive, I get a call from Robert. He had an epiphany: ‘We should try germanium diodes!’ Going from silicone to germanium diodes, you’re going from asymmetrical to symmetrical clipping, and it’s going to be a little less compressed. And it turned out to be exactly what I was looking for. The germanium turned it into an ideal pedal for full-on gain and lead tones. Now the pedal is capable of a huge range of tones.”
Andy Timmons Reacts to Germanium Mode
Keeley elaborates about the Timmons’ “AT” Drive mode: “In Andy’s mode there are a pair of diodes—one is a regular silicon diode and one is an LED. They have two different rates at which they start to conduct and it creates this asymmetrical clipping that I think kinda sounds like a tube. When you go to the RK mode [Robert Keeley’s original mode], that engages two back-to-back germanium diodes, which have a much lower voltage that they turn on. They also have an extra bit of capacitance which rounds off the highs. Because the Blues Driver is such a dynamic circuit, when you make a change there it’s going to be amplified and distorted further. These little differences between the silicon and germanium diodes are really amplified.”
The Human Factor ... Blended with Science
Another important current in the development of the Muse Driver: the increased use of advanced scientific tools at the Keeley shop, part of the company’s continuing evolution since it relocated to its new factory in 2021.
“We began using Audio Precision Analyzers starting in around May 2023,” Keeley explains. “We now have several of them so we can test every unit and make sure each unit is spot on, beyond the scope of human hearing. Every pedal gets a ‘birth certificate’ when it passes the analyzer test. I think that when we acquired those analyzers, Keeley Electronics went ‘professional audio,’ because now whenever we’re studying a rare vintage circuit of any kind, I can really see what it sounds like. And if Andy says, ‘I want less compression,’ I can huddle with the engineers and see how each stage of a circuit responds. It’s an amazing way to look at audio. It helps during the design phase and it helps during production. I now have a repeatable product that’s rock solid.”
Timmons lauds the scientific strides, but admits that the ultimate vindication arrives in your gut: “When you hit the ‘eureka’ moment and get it right, you can’t verbalize it. You feel it. Whether it’s the hair on your arms raising, or a smile on your face, you just know it’s there. That’s the only way to know. Sure, you can look at it on scopes and measure it on graphs—and those scientific measurements are certainly valuable—but the real test is how it makes you feel on a molecular level.”
Keeley agrees with a laugh: “The major benefit of working with a guy like Andy—and not just relying on a bunch of expensive analyzers and measurement tools—is that he really cares about all the nuances and dynamics! He’s an incredible player that LIVES in the world of dynamics and will explore the entire range. He shows how these circuits actually work for players, instead of machines.”
“The new era of Keeley is really a dream come true for me.” Keeley continues. “For 20 years I would look at other people’s equipment and how they progressed, and I finally feel like I’m at the point where I can take information from artists and their desires, and I can mix it with some of the great people and equipment that we have at the shop. We can study the circuits and listen to them in ways that we’ve never been able to do before.”
Keeley Factory Tour Drone Video
04 10 2023 Drone VideoMore Drives To Come!
The Muse Driver’s flexibility, with its two toggle switches for selecting overdrive voicing and tone stacks, is a hallmark of Keeley’s new series, which debuted with the Muse Driver’s predecessor, the Noble Screamer.
This powerful, versatile approach will culminate in spring 2024 with the release of three more overdrives in the series. Each will feature a pair of overdrive options based on iconic circuits—ranging from soft-clipping favorites to brawny, hard-clipping stalwarts—along with extra tone-shaping capabilities.
But in the meantime, Robert Keeley and his team are savoring the results of the rigorous-but-enjoyable process that yielded the new Muse Driver. “These signature pedals with Andy Timmons are really special,” Keeley says. “They have to be dynamic, expressive instruments in their own right. I know it might sound old-fashioned and quirky, but Andy’s name doesn’t go onto these pedals until he’s satisfied. It’s a lot of work, but it’s also so much fun.”
- Keeley Compressor Mini Review ›
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We’re giving away more gear! Enter Stompboxtober Day 24 for your chance to win today’s pedal from Maxon!
Maxon OD-9 Overdrive Pedal
The Maxon OD-9 Overdrive Effects Pedal may look like your old favorite but that's where the similarity ends. Improved circuitry with a new chip yields the ultra-smooth dynamic overdrive guitarists crave. Drive and Level controls tweak the intensity and volume while the Hi-Boost/Hi-Cut tone controls adjust brightness. Features true bypass switching, a die-cast zinc case, and 3-year warranty. From subtle cries to shattering screams, the Maxon OD-9 delivers a huge range of tones.
Features
Improved circuitry with a new chip yields ultra-smooth dynamic overdrive
Drive and Level controls tweak the intensity and volume
Hi Boost/Hi Cut tone controls adjust brightness
True bypass switching
Die-cast zinc case
AC/DC operation (order optional Maxon AC210N adapter)
Product Specs
Input: 1/4" mono jack
Output: 1/4" mono jack
Power: 9V DC, 6 mA, center pin minus (not included)
Dimensions: (WxDxH) 74 mm x 124 mm x 54 mm
Weight: 580g
Fender’s Greasebucket system is part of Cory Wong’s sonic strategy.
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.
Your 100 Guitarists hosts are too young to have experienced SRV live. We’ve spent decades with the records, live bootlegs, and videos, but we’ll never know quite how it felt to be in the room with SRV’s guitar sound.
Stevie Ray Vaughan was a force of nature. With his “Number One” Strat, he drove a veritable trove of amps—including vintage Fenders, a rotating Vibratone cab, and a Dumble—to create one of the most compelling tones of all, capable of buttery warmth, percussive pick articulation, and cathartic, screaming excess. As he drew upon an endless well of deeply informed blues guitar vocabulary, his creativity on the instrument seemingly knew no bounds.
Your 100 Guitarists hosts are too young to have experienced SRV live. We’ve spent decades with the records, live bootlegs, and videos, but we’ll never know quite how it felt to be in the room with SRV’s guitar sound. So, we’d like to spend some time imagining: How did it feel when it hit you? How did he command his band, Double Trouble? The audience?
SRV was mythical. His heavy-gauge strings tore up his fingers and made a generation of blues guitarists work a lot harder. And his wall of amps seems finely curated to push as much air in all directions as possible. How far did he take it? Was he fine-tuning his amps to extreme degrees? Or could he get his sound out of anything he plugged into?