Note the two trimmer screwdriver slots, surrounded by blue, in the middle of this phase shifter.
Potentiometers are used for most of the controls on pedals and a lot of other electronic equipment as well. A potentiometer (also known as a pot) is defined as a 3-terminal variable resistor in which the resistance is manually varied to control the flow of electrical current. A potentiometer acts as an adjustable voltage divider. Any control on a guitar pedal that has a knob will typically be controlling a potentiometer, or sometimes a rotary switch.
There is a type of potentiometer called a trimmer (also known as a trimpot) that lives inside of some stompboxes. It typically doesn’t have a shaft that sticks up like a regular potentiometer. Trimmers usually have a slot on top for making adjustments with a small screwdriver. They are meant to be set correctly when installed in a device, and mostly never seen or adjusted by the device’s user. Trimmers can be variable resistors, variable capacitors, or trimmable inductors, and they can perform many different types of functions within a circuit.
“I know what an epiphany it can be to unlock that little extra bit of magic out of an already beloved pedal.”
I get a fair amount of questions about trimmers—often: “Is it okay to mess with that?” There are many pedals on the market that have internal trimmers that can be adjusted by users, to tweak to personal taste. It is handy to be able to dial a sound in all the way, almost like fine-tuners on a guitar. Typical user-tweakable micro controls are for modulation speed and/or width, gain, and sensitivity.
Conversely, there are trimmers built into circuits that I would not consider easily user-adjustable. These include things like bias for time-based effects and setting proper voltages so circuits can function as they should. I’ve repaired quite a few analog delays and flangers, for example, that were perfectly functional! The bias had simply drifted out of its sweet spot. Perhaps the user had gotten too curious and decided to tweak those irresistible little trimmers? Or, more often than not, the trimmers had simply drifted a bit away from their set positions over many years of use, not to mention jostling from being transported to and from gigs. A qualified pedal tech has the right meters and test equipment to get those effects dialed right back in. However, bias can be a nightmare to get back to where it needs to be without some expertise. I understand why these folks thought their pedals were broken. A modulation effect that isn’t properly biased can sound absolutely horrible!
Internal timmers, aka trim pots, come in a variety of shapes and sizes. Look for the slots.
It’s only natural to be curious about the guts inside pedals. Trimmers can add so much extra versatility to a device. If you’re ever unsure which ones are okay to tweak, a good rule of thumb is to ask the builder or the company that makes a particular unit which of its trimmers are okay to fiddle with before you twiddle. In some cases, your warranty could be voided if you do adjustments, so it’s always a good idea to check first.
I know from my own playing what an epiphany it can be to unlock that little extra bit of magic from an already beloved pedal, and I enjoy sharing any knowledge that can help guitarists get the sounds that are most pleasing out of their effects. Perhaps that pedal you planned to trade could be transformed into something you really love with a little twist of a trimmer.
A Deeper Dive
I mentioned resistors several times in this column. A resistor is a passive, 2-terminal electrical component that controls electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses.
- Does your favorite stomp have an adjustable trimmer? You can find a list of popular guitar pedals that have adjustable trimmers here.
- To read more about voltage dividers, and how a potentiometer works, check this article out.
- And here’s some great information about trimmers, for further exploration.
- Killer Pedals Under $100 - Premier Guitar ›
- Behind the Bucket Brigade - Premier Guitar ›
- 5 DIY Mods to Perfect Your Ibanez TS9 and Boss SD-1 - Premier ... ›
Complete with a range of game-changing design features, such as the patent-pending attachable FREERIDE Wheel System, premium water-resistant and reflective materials, shockproof shell structure and improved ergonomic features, the Vertigo Ultra Bass takes gear protection to the next level.
The Vertigo Ultra Bass features:
- Patent-pending FREERIDE Wheel System that allows for wheels to be attached on the case in no time, giving you the option to travel with it seamlessly
- Upgraded materials, including a water-resistant 1680D Ballistic Nylon outer shell, plush inner lining and new reflective trim for maximum backstage and night visibility
- Enhanced protection with a shockproof shell structure and heavy-duty water-resistant YKK zippers for protection from the elements
- Improved ergonomics and functionality including added back support and load-lifting detachable shoulder straps with side release buckles
- Flexible storage options with added space for touring essentials
MONO Vertigo Ultra Electric Bass Gig Bag - Black
For more information, please visit monocreators.com.
The G-Bird, the newest addition to the Generation Collection--represents the glorious legacy of the Gibson Hummingbird colliding with modern sonic enhancement through the Gibson Player Port to add a new dimension to the G-Bird sound. The Gibson Player Port allows players to hear more of themselves as the audience hears it. With a tone that is crisp and resonant, all of the Gibson Generation Collection acoustics are designed to be comfortable to hold and play for long periods of time. All Generation Collection guitars feature the Gibson Player Port, slim, lightweight bodies, a flatter fingerboard radius, Walnut back and sides, Sitka spruce tops, and a stunning Natural finish. Additionally, the new G-Bird, and the G-200 and G-Writer are equipped with LR Baggs™ Element Bronze pickup systems which amplify deep bass and crystal-clear highs.
G-Bird
The G-Bird represents the glorious legacy of the Gibson Hummingbird with modern sonic enhancement through the Gibson Player Port adding a new dimension to the G-Bird’s sound. The G-Bird features a stunning solid Sitka spruce top and solid walnut back and sides for the ultimate in crisp, resonant tone. This square-shoulder dreadnought delivers all the rich low end and well-balanced mids and highs the original Hummingbird is famous for. The TUSQ nut and saddle, along with chrome Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning. The utile neck, with its easy-playing Advanced Response neck profile, is so comfortable you won’t want to put it down. The G-Bird also comes equipped with an LR Baggs Element Bronze pickup system, so it will always sound as good to your audience as it does to you. The G-Bird also comes equipped with an LR Baggs™ Element Bronze pickup system, so it will always sound as good to your audience as it does to you. The G-Bird is available in Natural finish. A gig bag is included.
G-00
Modeled after Gibson’s pioneering small-body parlor acoustic guitars from the 1930’s, the G-00 is a top choice for blues and fingerstyle guitar performances. Despite its more compact size, the G-00 achieves a full, balanced sound. The G-00 fills any room with rich tones-which players can hear like never before, with the exclusive Gibson Player Port. Like all models in the Gibson Generation Collection, the G-00 is handcrafted in Bozeman, Montana, by the same highly--skilled craftspeople who make all Gibson acoustic guitars. The G-00 features a beautiful solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The slightly thinner G-00 parlor-sized body is exceptionally comfortable to hold and play. The TUSQ nut and saddle along with the Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-00 is available in Natural finish. A gig bag is included.
G-45
The G-45, a round-shouldered jumbo, adds the Gibson Player Port to its famous “Workhorse” J-45 style body, which is Gibson’s best-selling acoustic guitar of all time. On the G-45, players can now hear more clearly than ever how this beloved guitar responds to every style and technique of playing. Powerful one moment and soft the next, the G-45 delivers all sounds with incredible dynamic range in an elegant, medium body size. The G-45 is part of the Gibson Generation Collection and like all models in this collection, it is handcrafted in Bozeman, MT, by the same highly skilled craftspeople who make all Gibson acoustics. It features a solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The G-45 features a slightly thinner round shoulder body is exceptionally comfortable to hold and play. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners deliver solid tuning stability, so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-45 is available in Natural finish. A gig bag is included.
G-Writer
Gibson’s impressive range of square-shouldered guitars have become an expressive standard for rock, pop, folk, and country artists. The G-Writer is known for its wide range of sounds, from gutsy and loud, to soft and sweet; they are superb for all styles and shine, whether strumming chords or fingering intricate solos. The G-Writer comes ready for the stage or studio with an LR Baggs Element Bronze pickup system and the ear-opening Gibson Player Port. The G-Writer is part of the Gibson Generation Collection and like all models in this collection, it is handcrafted in Bozeman, MT, by the same highly skilled craftspeople who make all Gibson acoustics. It features a solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The G-Writer features a slightly thinner cutaway body, is more comfortable to play and provides effortless access to the upper frets. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners deliver solid tuning stability, so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-Writer is available in Natural finish. A gig bag is also included.
G-200
Gibson built its first “Super Jumbo” SJ-200 as a custom order for country and western singer and film star Ray Whitley, who desired a big, loud, and deep flat-top over which to croon. The SJ-200 quickly became a staple of cowboy singers and horseback troubadours, and then country music, 60’s folk stars, and onto every acoustic guitar genre that has followed. Ray would be proud to hear the booming sound from the Gibson Player Port on the new G-200, which comes ready for the stage or studio with a LR Baggs Element Bronze pickup system. Like all models in the Gibson Generation Collection, the G-200 is handcrafted in Bozeman, MT, by the same highly--skilled craftspeople who make all Gibson acoustics. The G-200 features a beautiful solid Sitka spruce top and solid Walnut back and sides for tone that sounds crisp and resonant. The slightly thinner G-200 cutaway jumbo body is exceptionally comfortable to hold and provides excellent access to the upper frets. The TUSQ nut and saddle, along with the Grover Mini Rotomatic tuners, deliver solid tuning stability so you can spend more time playing instead of tuning, and the utile neck with its easy-playing neck profile is so comfortable you won’t want to put it down. The G-200 is available in Natural finish. A gig bag is also included.
G-Bird | Generation Collection
Gibson Acoustic Generation Collection G-Bird Acoustic-electric Guitar - Natural
For more information, please visit gibson.com.
