
Fig. A
When power cables and signal paths tangle, the results can be noisy. Here are some easy fixes.
In my previous State of the Stomp ["The Shocking Truth About Ground Loops," October 2021], I discussed how ground loops can be formed between the amplifiers in a multiple amp setup, and how to safely address them with an isolation transformer. As a brief reminder, a ground loop is created whenever two electrical circuits that theoretically have the same ground potential actually have a non-zero potential between them in practice, and that often results in hums and buzzes that are harmonically related to the mains voltage frequency in your part of the world.
Oh, how I wish that was the only means of making a ground loop! Tennyson certainly didn't have ground loops in mind when writing that nature was red in tooth and claw, but as someone who has built guitar rigs for around 25 years, it is hard to shake the idea that they serve a merciless and maniacal natural force that actively resists the pristine and well-ordered world of quiet, toneful pedalboards and rack systems.
These loops are made by the way we wire our stompboxes and the environment around them. The ones in this month's ground loop fest may be a bit more identifiable than the loops in the multi-amp scenario. In that case, part of the loop is hidden in your venue's installed power cabling. This time, we're going to discuss loops that exist wholly and entirely in your pedalboard itself.
"Tennyson certainly didn't have ground loops in mind when writing that nature was red in tooth and claw."
The first ground loop we'll discuss is a potential loop created by using daisy-chain power cables, where one power supply feeds multiple pedals. In this setup, you can make a loop via the power cables connecting two pedals and the audio cables connecting them. There is a clear ground path in Fig. A that goes from stompbox to stompbox via the audio cables. If that were the only path, there would be little chance for a loop to be formed. But if you add in the ground path made by the power cables, you can now see a circuitous path that connects the first and last pedal through the audio cables and then doubles back through the power daisy chain. This circle of wire is our loop.
A second loop type is shown in Fig. B. Most loop switchers tie the ground connections of the send and return jacks together, and when the loop switcher is connected to a stompbox, the audio cables make a ring of ground conductors. So each loop switcher loop can actually make a ground loop. Yay!
There are countless loop switcher-equipped boards out in the world. Why don't all of them hum? Ground loops can generate hum when they are driven by an outside electromagnetic field. (Bill Whitlock's Audio Engineering Society treatise "Ground Loops: The Rest of the Story" gives great theoretical and experimental explanation of EMF—electromotive force—induced ground loops.) When the ground looped cable encircles an EMF field, that field can develop a current in the wire that can translate into audible hum in your rig. So if your power/audio cable loop or your loop switcher loop wraps around a power supply transformer or a high-current, noisy power cable at a venue or in your home, you may get an induced hum that you can hear in your amplifier's output.
Fig B.
So, what can be done? Fig. A shows how daisy-chained power can make a giant ground loop susceptible to picking up stray EMF. Using isolated power for every pedal will break this loop and keep it from generating noise. If you must share power amongst pedals on your board, make sure they are next to one another in your signal chain so that the loop size (and associated hum) is minimized.
For Fig. B, the cables to and from the pedal can be as short as possible and run as close to one another as possible. This too will decrease the area encircled by the loop and commensurately minimize the induced current. Special care should be taken to make sure looping cables do not surround or run near power supplies or wall warts. The type of power supply can make a difference as well, since those from Truetone or Strymon switch at higher frequencies that are less likely to be induced in the first place, and less likely to be heard if they are.
While this is hardly a 100 percent complete picture of the cruel world of ground loops, you hopefully are armed with enough knowledge to have insight into exactly what could be causing those wayward noises and buzzes in your rig and how to clear them out to make way for a much more gratifying set of buzzes and noise.
- Got Noise Issues? It Could Be Your Pedalboard's Power Supply ... ›
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The country virtuoso closes out this season of Wong Notes with a fascinating, career-spanning interview.
We’ve saved one of the best for last: Brad Paisley.The celebrated shredder and seasoned fisherman joins host Cory Wong for one of this season’s most interesting episodes. Paisley talks his earliest guitar-playing influences, which came from his grandfather’s love of country music, and his first days in Nashville—as a student at Belmont University, studying the music industry.
The behind-the-curtain knowledge he picked up at Belmont made him a good match for industry suits trying to force bad contracts on him.
Wong and Paisley swap notes on fishing and a mutual love of Phish—Paisley envies the jam-band scene, which he thinks has more leeway in live contexts than country. And with a new signature Fender Telecaster hitting the market in a rare blue paisley finish, Paisley discusses his iconic namesake pattern—which some might describe as “hippie puke”—and its surprising origin with Elvis’ guitarist James Burton.
Plus, hear how Paisley assembled his rig over the years, the state of shredding on mainstream radio, when it might be good to hallucinogenic drugs in a set, and the only negative thing about country-music audiences.
Tom Bedell in the Relic Music acoustic room, holding a custom Seed to Song Parlor with a stunning ocean sinker redwood top and milagro Brazilian rosewood back and sides.
As head of Breedlove and Bedell Guitars, he’s championed sustainability and environmental causes—and he wants to tell you about it.
As the owner of the Breedlove and Bedell guitar companies, Tom Bedell has been a passionate advocate for sustainable practices in acoustic guitar manufacturing. Listening to him talk, it’s clear that the preservation of the Earth’s forests are just as important to Bedell as the sound of his guitars. You’ll know just how big of a statement that is if you’ve ever had the opportunity to spend time with one of his excellently crafted high-end acoustics, which are among the finest you’ll find. Over the course of his career, Bedell has championed the use of alternative tonewoods and traveled the world to get a firsthand look at his wood sources and their harvesting practices. When you buy a Bedell, you can rest assured that no clear-cut woods were used.
A born storyteller, Bedell doesn’t keep his passion to himself. On Friday, May 12, at New Jersey boutique guitar outpost Relic Music, Bedell shared some of the stories he’s collected during his life and travels as part of a three-city clinic trip. At Relic—and stops at Crossroads Guitar and Art in Gilbertsville, Pennsylvania, and Chuck Levin’s Washington Music Center in Wheaton, Maryland—he discussed his guitars and what makes them so special, why sustainability is such an important cause, and how he’s putting it into practice.
Before his talk, we sat in Relic’s cozy, plush acoustic room, surrounded by a host of high-end instruments. We took a look at a few of the store’s house-spec’d Bedell parlors while we chatted.
“The story of this guitar is the story of the world,” Bedell explained to me, holding a Seed to Song Parlor. He painted a picture of a milagro tree growing on a hillside in northeastern Brazil some 500 years ago, deprived of water and growing in stressful conditions during its early life. That tree was eventually harvested, and in the 1950s, it was shipped to Spain by a company that specialized in church ornaments. They recognized this unique specimen and set it aside until it was imported to the U.S. and reached Oregon. Now, it makes the back and sides of this unique guitar.
A Bedell Fireside Parlor with a buckskin redwood top and cocobolo back and sides.
As for the ocean sinker redwood top, “I’m gonna make up the story,” Bedell said, as he approximated the life cycle of the tree, which floated in the ocean, soaking up minerals for years and years, and washed ashore on northern Oregon’s Manzanita Beach. The two woods were paired and built into a small run of exquisitely outfitted guitars using the Bedell/Breedlove Sound Optimization process—in which the building team fine-tunes each instrument’s voice by hand-shaping individual braces to target resonant frequencies using acoustic analysis—and Bedell and his team fell in love.
Playing it while we spoke, I was smitten by this guitar’s warm, responsive tone and even articulation and attack across the fretboard; it strikes a perfect tonal balance between a tight low-end and bright top, with a wide dynamic range that made it sympathetic to anything I offered. And as I swapped guitars, whether picking up a Fireside Parlor with a buckskin redwood top and cocobolo back and sides or one with an Adirondack spruce top and Brazilian rosewood back and sides, the character and the elements of each instrument changed, but that perfect balance remained. Each of these acoustics—and of any Bedell I’ve had the pleasure to play—delivers their own experiential thumbprint.
Rosette and inlay detail on an Adirondack spruce top.
Ultimately, that’s what brought Bedell out to the East Coast on this short tour. “We have a totally different philosophy about how we approach guitar-building,” Bedell effused. “There are a lot of individuals who build maybe 12 guitars a year, who do some of the things that we do, but there’s nobody on a production level.” And he wants to spread that gospel.
“We want to reach people who really want something special,” he continued, pointing out that for the Bedell line, the company specifically wants to work with shops like Relic and the other stores he’s visited, “who have a clientele that says I want the best guitar I can possibly have, and they carry enough variety that we can give them that.”
A Fireside Parlor with a Western red cedar top and Brazilian rosewood back and sides.
A beautifully realized mashup of two iconic guitars.
Reader: Ward Powell
Hometown: Ontario, Canada
Guitar: ES-339 Junior
I’ve always liked unusual guitars. I think it started when I got my first guitar way back in 1976. I bought a '73 Telecaster Deluxe for $200 with money I saved from delivering newspapers.
I really got serious about playing in 1978, the same year the first Van Halen album was released. Eddie Van Halen was a huge influence on me, including how he built and modded guitars. Inspired by Eddie, I basically butchered that Tele. But keep in mind, there was once a time when every vintage guitar was just a used guitar—I still have that Tele, by the way.
I never lost that spirit of wanting guitars that were unique, and have built and modded a few dozen guitars since. When I started G.A.S.-ing simultaneously for a Les Paul Junior and a Casino, I came up with this concept. I found an Epiphone ES-339 locally at a great price. It already had upgraded CTS pots, Kluson tuners, and the frets had been PLEK’d. It even came with a hardshell case. It was cheap because it was a right-handed guitar that had been converted to left handed and all the controls had been moved to the opposite side, so it had five additional holes in the top.
Fortunately, I found a Duesenberg wraparound bridge that used the same post spacing as a Tune-o-matic. I used plug cutters to cut plugs out of baltic birch plywood to fill the 12 holes in the laminated top. I also reshaped the old-style Epiphone headstock. Then, I sanded off the original finish, taped the fretboard, and sprayed the finish using cans of nitro lacquer from Oxford Guitar Supply. Lots of wet sanding and buffing later, the finish was done.
I installed threaded insert bushings for the bridge, so it will never pull out. The pickup is a Mojotone Quiet Coil P-90 and I fabricated a shim from a DIY mold and tinted epoxy to raise the P-90 up closer to the strings. The shim also covers the original humbucker opening. I cut a pickguard out of a blank and heated it slightly to bend it to follow the curvature of the top.
All in all, I'm pretty happy how it turned out! It plays great and sounds even better. And I have something that is unique: an ES-339 Junior.
ENGL, renowned for its high-performance amplifiers, proudly introduces the EP635 Fireball IR Pedal, a revolutionary 2-channel preamp pedal designed to deliver the legendary Fireball tone in a compact and feature-rich format.
The EP635 Fireball IR Pedal brings the raw power and precision of the ENGL Fireball amplifier into a pedalboard-friendly enclosure, offering unmatched flexibility and tonal control for guitarists of all styles. This cutting-edge pedal is equipped with advanced features, making it a must-have for players seeking high-gain perfection with modern digital convenience.
Key Features:
- Authentic Fireball Tone – Designed after the renowned ENGL Fireball amplifier, the EP635 delivers the unmistakable high-gain aggression and clarity that ENGL fans love.
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- Built-in Midboost Function – Enhance your tone with the integrated Midboost switch, perfect for cutting through the mix with extra punch.
- Advanced Noise Gate – Eliminate unwanted noise and maintain articulate clarity, even with high-gain settings.
- IR (Impulse Response) Loading via USB-C – Customize your sound with user-loadable IRs using the included software, bringing studio-quality cab simulations to your pedalboard.
- Headphone Output – Silent practice has never been easier, with a dedicated headphone output for direct monitoring.
- Premium Build and Intuitive Controls – Featuring a rugged chassis and responsive controls for Volume, Gain, Bass, Middle, Treble, and Presence, ensuring precise tonal shaping.
SPECS:
- Input 1/4” (6,35mm) Jack
- Output 1/4” (6,35mm) Jack
- Headphone Output 1/8”(3,5mm) Jack
- 9V DC / 300mA (center negativ) / power supply, sold separately
- USB C