
Discover the sound-sculpting properties of bright caps and how to tame treble acoustically.
I enjoy clarity and chime, so I really like the open-top-end sound of a bright cap across the volume pot. Some folks do not and remove them, finding mellow mojo. What follows is an explanation of what bright caps are and how they work, plus general treble tips to consider on our journey from kilocycles to kilohertz.
When a guitar signal travels through an amp and encounters a large resistance, the high frequencies tend to sound more attenuated or shelved compared to the lower frequencies. Bright caps exist to restore this perceived loss of openness and treble. The features on most analog amps work by subtraction—throwing signal away (series resistance) to create an aural effect. Passive tone controls, reverb circuits, and volume controls are prime examples. Almost every classic guitar amp has a bright cap on the volume control. A volume potentiometer will typically be a 1-megaohm resistor with a variable tap/wiper. The top of the pot (the resistor) is connected to the signal source and the bottom is connected to ground (zero signal). The wiper sweeps between the two ends and is our variable output level—controlling the volume range, from silent to loud.
Vive la résistance! Let’s consider a loud-ish at-home playing level, with the volume set to 3. I’m visualizing a classic blackface Fender volume knob here. How does this setting translate into series resistance? It’s around 850,000 ohms! That’s 850k ohms in series to the wiper (output) and 150k ohms to ground: 1-megaohm total (Image 1). The snappy guitar signal enters the 850k resistance but sounds dull and flat once it passes through. How do we fix that? That’s where a bright cap comes in. A small-value capacitor—usually in the 47-to-250 pico farad (pF) range—is connected from the pot’s maximum signal point to the wiper output. Now the highs jump over the 850k resistance through the bright cap to the wiper and out to the next stage, creating sonic balance. In this example, a typical blackface signal passing through a 100 pF bright cap allows highs in the 2,000 Hz range and more to pass the resistor more easily. So, our guitar’s “air” and glassy leading edge is restored!
If you want more of a good thing, increase the bright cap’s value and the fast-lane frequency drops lower, allowing more and more upper-mid bite along with the shimmer. Or reduce the bright cap value for a rounder, softer sound. Often just a little is enough for clean tones. High-gain and classic British amps have big bright cap values of 500 pF up to 5000 pF (or .005 µF). Large bright caps like that over a 1-megaohm pot really push upper mids and give you searing overdrive. Such big cap values are generally not good for clean tones and can sound “honky” when you turn the volume down.
Many favored amps have bright caps. Fender Twins and Super Reverbs have a 10 pF bright cap over a 3.3-megaohm series signal resistor. In many Marshall amps there is a 500 pF bright cap over the 470k resistor leading to the second gain stage.
So how can we use this info? If you have an amp you feel is too edgy or bright for your taste, you can remove or change the value on one of these caps and see if you like the sound better. Volume pot bright caps are easy to experiment with. Try smaller values than stock for a more subtle lift in the top or go larger for more aggressive tones. You can also add a series resistor in line with your bright cap. This will pad down the bright cap’s effect and soften the leading edge. Note: If you don’t know how to discharge caps, then a tech is the way to go for safety’s sake. Bright cap mods are straightforward, so they should be affordable.
More treble tips. But before trying any internal mods, experiment with room position and treatment. You probably know this, but it’s worth repeating: single-coil pickups are brighter than humbuckers, bridge position pickups are brighter than neck position, pickups raised closer to the strings are brighter, rooms with exposed hard surfaces (glass, uncovered hardwood floors, sheet rock, or brick walls) are brighter than rooms with rugs and soft furnishings. Amps sitting on the floor positioned near walls or corners sound fuller and darker compared to amps away from walls, and amps on raised platforms (stands or chairs) or tilted up are brighter. If your amp sounds too bright, try placing a small rug under and in front of it while keeping the amp close to a wall. This can do a surprising amount of tone shaping, and it’s easier than digging into the circuitry. In a live band setting, put your amp up on a chair and think of it as your personal monitor. Lifting it off the ground will help your sound cut through and stay tight, plus it puts the speaker closer to your ear level. One more thing: Mid controls contain a lot of treble, too, so experiment with lowering mids to reduce treble.
WARNING:
All tube amplifiers contain lethal voltages. The most dangerous voltages are stored in electrolytic capacitors, even after the amp has been unplugged from the wall. Before you touch anything inside the amp chassis, it’s imperative that these capacitors are discharged. If you are unsure of this procedure, consult your local amp tech.Billy Strings' signature dreads are distinguished by a 25" scale and wider nut width.
In a career defined by evolution, Joe Bonamassa is ready to turn the page once again. The blues-rock virtuoso has just announced Breakthrough, his most adventurous and genre-blending studio album to date, out July 18th via his own J&R Adventures.
At the heart of the announcement is the release of the album’s powerful title track—“Breakthrough' —a soulful, hard-hitting anthem about letting go, moving forward, and finding your fire again, available today on all streaming platforms.
Crafted across multiple continents and infused with a world’s worth of inspiration, Breakthrough marks a bold new chapter for Bonamassa—one that leans on fiery solos, emotionally rich storytelling, groove-driven arrangements, and stylistic exploration. Produced by longtime creative partner Kevin Shirley (Iron Maiden, The Black Crowes, Journey), the album was shaped by sessions in Greece, Egypt, Nashville, and Los Angeles, resulting in a vibrant sonic tapestry that shifts effortlessly from funky blues and Texas swing to acoustic ballads and swaggering hard rock.
Joe Bonamassa “Breakthrough” - Official Lyric Video
Watch the official lyric video for "Breakthrough" by Joe Bonamassa
“I think this album, Breakthrough, marks a shift in the styling of Joe Bonamassa’s recording output,” says Shirley. “While there are plenty of guitar solos on this record, his emphasis has been on songs primarily. Each time Joe undertakes a new recording project, he seems to access a different part of his vast library of music genre from the jukebox-in-his-head! This album is a round-the-world musical trip—from Little Feat funkiness to Texas swing, from hard rock power to acoustic singer/songwriter-style songs.”
The newly released single “Breakthrough,” co-written with longtime collaborator Tom Hambridge (Buddy Guy, ZZ Top, Lynyrd Skynyrd), captures the emotional core of the record—an uplifting anthem about transformation, persistence, and letting go of the weight that holds us back. With gritty vocals, melodic guitar lines, and lush instrumentation, the track embodies Bonamassa’s signature blend of power and finesse while ushering in a bold new direction.
“Breakthrough” follows the success of Bonamassa’s recent singles “Still Walking With Me” and “Shake This Ground,” both of which hinted at the adventurous spirit behind the full album. “Shake This Ground” delivered a moody, introspective edge, while “Still Walking With Me” leaned into warmth, gratitude, and classic soul. Each track reflects a different facet of Bonamassa’s evolving songwriting approach, rooted in emotional honesty and anchored by his unmistakable guitar work.
The album announcement caps a stretch of extraordinary momentum for Bonamassa. Next up, Bonamassa recently began his extensive *European Spring Tour, followed by a June run with his powerhouse supergroup Black Country Communion* (featuring Glenn Hughes, Jason Bonham, and Derek Sherinian). After another round of summer dates across Europe—including sold-out shows in Ireland—he’ll return stateside for his just-announced* 2025 U.S. Summer Tour*, a limited amphitheater run featuring stops at The Greek Theatre, Red Rocks, and more iconic venues.
With over 50 albums, 28 #1 Billboard Blues albums, and a lifelong commitment to evolving the genre, Bonamassa shows no signs of slowing down. Whether headlining iconic venues, mentoring rising artists through Journeyman Records, or supporting music education via his Keeping the Blues Alive Foundation, Bonamassa continues to shape the future of blues-rock with every note.
For more information on Breakthrough, tour dates, and VIP packages, visit jbonamassa.com.
Why is Tommy’s take on “Day Tripper” so hard? And what song would Adam Miller never play with him? Plus, we get Adam’s list of favorite Tommy Emmanuel records.
We call guitarist Adam Miller in the middle of the night in Newcastle, Australia, to find out what it’s like to play with Certified Guitar Player, Tommy Emmanuel. Miller tells us just how famous Tommy is in Australia, and what it was like hearing him play from a formative age. Eventually, Adam got to open for Emmanuel, and they’ve since shared the stage, so we get the firsthand scoop: Why is Tommy’s take on “Day Tripper” so hard? And what song would Miller never play with him? Plus, we get Adam’s list of favorite Tommy Emmanuel records.
Adam’s newly released trio album, Timing, is out now.
Plus, we’re talking about new recordings from Billy Strings and Bryan Sutton, as well as Brooklyn Mediterranean surf party band Habbina Habbina.
Peavey Electronics announces the Decade preamp pedal. The internet and social media have been abounding with chatter about the current recording secret of the modern-day guitar gods – the Peavey Decade practice amp.
The discontinued amp has reached unimaginable demands on the secondary markets. So much so that small pedal builders have made attempts to capitalize and duplicate the proprietary designs themselves. Tone chasers can now rejoice as the Decade preamp pedal now brings those highly sought after tones back to market in a small, compact footprint.
Guitar players will find a single input, single output preamp pedal straight forward and easy to navigate. Faithful to the original Decade circuitry (circa 1980), the control layout will be identical to the original amplifier. The GAIN section features PRE and POST controls. PREGAIN sets the gain of the input circuitry. POST GAIN sets the gain before the out. Built off the legendary Peavey Saturation patent, the new, switchable SATURATION allows tube-like sustain and overload at all volume levels, suitable for bedrooms, rehearsals, stadiums and apparently, those very expensive recording studios. The traditional BASS, MID, and HIGH equalization controls provide the tone shaping enhancements any guitar should require. Upgraded pedal features include an internal 24v supply from the standard 9v supply/battery and worldwide EMC/FCC compliance approval.
To learn more, visit online at www.Peavey.com
Street $199.99 USD