If you’ve owned a tube amp for pretty much any amount of time, you’ve been there: Your amp starts making noise—probably at the worst possible moment, whether onstage, in the studio, at rehearsal, or when you just really want to play—and you don’t know what to do. Maybe you keep it cool, but maybe you panic: Is my amp broken for good? Is this going to cost me hundreds of dollars? Fortunately, there are a few basic things you can check before you call your amp tech in a frenzy.
Ultimately, an all-tube guitar amp is actually a very durable device. But it’s important to remember that these amps need maintenance and have parts that are going to need to be replaced over the course of their lives—and tubes are the most likely place to check when you’re having a problem.
Many vacuum tubes are “military grade,” which means they can withstand shock, vibration, humidity, temperature, and many other harsh conditions. That doesn’t mean they are fail-proof, though. So, when your amp is making noise, here are some ways to check out your tubes.
Look
Do a visual inspection. Are your amp’s tubes bright and shiny, or do they look weathered and dirty? If they look old, they may be old. This doesn’t have to be a sign of something wrong, but tubes wear out like lightbulbs—they work until they don’t. I usually say power tubes have a two- to five-year lifespan (for professionals, it’s more like six months to two years). Preamp tubes have more like a five- to 20-year life. They can function longer but start to get problematic before they just die.
Look at what’s going on inside. Is the clear part of the glass still clear? If there is a smoky look on the inside of the glass, that is a sign of heavy wear. Look at the shiny mirror-looking part; that is the getter flashing. It should look bright, though sometimes there is a little fuzziness along the edges. If it is getting smoky, then the tube is tired. And if it has gone completely white, the tube is toast.
The last visual is best done in darkness. Look for the heater element inside. It is a wire in the very center of the tube structure that glows red when operating. Don’t worry about what shape it is, how much you can see it, or if it looks exactly like the other tubes. If it is glowing, it’s good; if it is dark in there, it’s toast.
In his final PG column, the amp maker to the stars teaches you how to troubleshoot your guitar’s loudhailer if it’s raising a sonic ruckus.
Listen
Let’s move on to audible diagnostics. The amp works but is making extraneous noises. The first thing to do is unplug the guitar cable from the input of the amp, so nothing is plugged in, the amp is fully on, and the tone controls, volume, and master (if applicable) are full on. What noises do you hear? If it is silent with a tiny little bit of background noise, that is as good as a guitar amp gets.
Are you hearing an electronic, almost morse-code sound? A common modern problem is RF (radio frequency) noise from routers, cell phones, and transmission towers. It is not the amp and there is nothing to fix, but if you try moving the amp around the room or building, you may find a quieter place.
Is the amp making a constant “shhhhh” sound? Does it get louder if you turn the volume knob up? That is thermionic emission, the noise of electrons flowing. It is a byproduct of gain. Low-gain amps have less, and high-gain amps suffer greatly. Some tubes can add to this, so if you replace the first couple tubes in the signal path and it helps drop the noise floor, then keep the noisy ones for less critical positions.
Is the amp sitting there doing the snap-crackle-and-pop thing? This can be a tube issue, but most of the time it is a component issue inside. If you have a known good tube, you can replace the tubes one at a time, seeing if the noise changes. If you find that it was a tube, that tube is toast, so don’t use it as a spare.
Now, let’s talk about microphonics. Because of the amount of gain we have in guitar amps, microphonic tubes can be problematic. Start turning the amp volume/gain all the way up. If you get a howl, like with an open microphone, you have a microphonic tube. If it is still behaving but you can tap on the amp and get a sound like tapping on a microphone, that can be acceptable.
Finding the Cause
There are multiple tubes in an amp, so let’s find the root of the noise. The first thing is tap testing. The best tool is a pencil with an eraser. One by one, tap on the tubes with the amp on and turned up. If you get a significant microphonic sound from one, it should be swapped out with a quieter one. Now, this is the thing: A little bit of microphonics is normal, so it will take a little getting to know your amp to learn what is acceptable or not. Certain brands/models of tubes are better than others, so just because it’s new doesn’t mean it’s better or even good. As you go down the line of the signal chain, the gain is less, so you are looking for slight noises. Once you get to the power tubes, they can be microphonic, but they don’t howl like a preamp tube. They make a thud sound when tapped.
The other thing we’re looking for with this tap testing is rattling. Again, there is a certain level of acceptable rattle. But if you can hear it through the speaker, that’s unacceptable. If you have power tubes that rattle, this sometimes does not come through the speaker, but you can hear it when playing the amp at lower levels. If that bothers you, then they need to be replaced even though they’re functioning properly.
The last diagnostic is pulling the preamp tubes (not the power or rectifier tubes). Starting with the first tubes in the signal chain, pull them out one at a time and listen to see if the noise goes away. If you pull a tube and the noise disappears, then either that tube is the culprit, or your problem lies in that part of the circuit.
If you’re looking for a quick fix to get you through your gig or session and you narrow your problem down to a tube, go ahead and swap it out. If your amp is fixed bias, you may still need to head to your tech tomorrow and have it biased, but you’ll get your work done today. And when in doubt, replace your old tubes. If it turns out that wasn't the issue, you now have good spares for when a tube does eventually give you problems.
Discover the magic of tone with the latest pedals! From the versatile Brothers AM to the warm Keeley Manis Overdrive, each offers unique sonic possibilities. Ready to elevate your sound? Dive into the Eventide H90's powerhouse effects or the compact CHO-mini's rich chorus. Which pedal will inspire your next masterpiece?
CHASE BLISS Brothers AM
A faithful tribute to the Analog Man King of Tone, the Brothers AM offers dual multi‑mode gain channels—boost, overdrive, or distortion—with intuitive controls, live tweakability, and four onboard custom presets. It adds a bonus treble‑booster circuit inspired by the Beano Boost, giving you extra bite and clarity. Fully MIDI, expression, and CV‑controllable, this pedal lets you save tones and stack effects while preserving the warm, transparent character of the original.
The Keeley MANIS Overdrive is a bold evolution of the mythical transparent drive, blending NOS germanium transistors and diodes for unmatched warmth, compression, and grit. With switchable voicings and dynamic touch response, it’s a tone-sculpting weapon built for players who demand both clarity and rich harmonic character in one pedal.
Eventide’s flagship H90 Harmonizer is a powerhouse multi-effects pedal. It features 70 effect algorithms, including reverb, delay, pitch shifting, modulation, and distortion, plus hundreds of curated programs. With comprehensive I/O and flexible routing, the H90 is built to be the heart of your rig, on stage or in the studio.
The Amp Academy Stomp is the latest in amp modeling from NUX. Included are several legacy amps, effects, Bluetooth with an app, workflow features, and more. Most importantly, the Amp Academy Stomp includes Image, which loads NAM profiles into the Amp Academy Stomp and, with black-box algorithms, accurately reproduces the dynamics and responsiveness of any amp profile loaded into the pedal.
The pocket-sized and feature-packed CHO-mini pedal delivers an outstanding selection of chorus tones at a budget-friendly price. With a selection of three curated and timeless chorus effects, the CHO-mini delivers a wealth of sonic possibilities in mono or spacious stereo imaging. Includes tap-tempo, true or buffered bypass, metal housing. Available from Osiamo.
The Fuhrmann Echoes pedal is a versatile delay unit, offering digital, modulated, and analog modes. It provides clear, modulated, or degrading (analog-like) delay repetitions, adjustable with a low-pass-filter control. Featuring tap tempo and two rhythmic subdivisions, this compact pedal delivers up when one delay is not enough.
Batverb is the stereo reverb that dreams are made of. Less of a room simulator and more of a tail-generating pedal, Batverb is an instrument in its own right. Batverb sings in any signal chain, with dedicated controls for suboctaves and overtones, saturation, ducking behavior, and more.
The Ampero II is the latest addition to the Ampero series, a second-generation multi-effects processor that brilliantly combines the iconic stage control of the original Ampero with the power of a new triple-core digital audio processing platform. Plus, a larger, sharper 5-inch dynamic touchscreen and newly designed system UI for smoother, and more intuitive interaction. All while maintaining the compact and lightweight design of the Ampero Series.
The Fuhrmann Stellar Stereo Reverb pedal delivers a broad range of reverbs, from short early reflections to long, floating tails. Users can seamlessly transition between nine stored reverb scenes with no noticeable delay. Intuitive controls allow for precise adjustments, making it a powerful and user-friendly addition for diverse sonic needs.
The DoubleTracker Stereo delivers lush, organic stereo doubling with adjustable delay, pitch, and spread. Featuring dual isolated paths, intuitive controls, and unique SYNC/COMP modes, it adds depth and dimension to any instrument—perfect for guitar, bass, keys, vocals, and studio work. It’s not chorus. It’s Double Tracking.
The Rock N Roll Relics Stinger overdrive has all the mojo of classic, yellow drive pedals, but with tonal refinements to bring it to the modern age. We use NOS construction, as you’ll come to expect with the Stinger Series, which gives it that authentic, ear-pleasing tone we all want.
Abyss is right. Electro-Harmonix’s Ocean’s Abyss, with two stereo reverbs and 10 reverb types, is fundamentally a reverb pedal. But it is deeper than that. Much, much deeper. EHX calls the Abyss an Advanced Reverb Laboratory. I’d venture that it is more like a reverb-centric multieffects unit, because the Oceans Abyss enables you to add effects that include chorus, distortion, delay, and bit-crushing to the expansive array of reverbs. But I’m not even sure my modified description does the pedal justice. It is a sound-design machine of impressive power—especially if you have the time and will to explore the breadth of its functions.
For a pedal that makes so many sounds, the Oceans Abyss’ control layout is fairly straight ahead, and compared to some of EHX's other superpedals it’s actually downright economical. The center screen displays a virtual pedalboard where you can manipulate effects and signal routing via a control knob and just a few buttons. The reverb controls themselves, meanwhile, are easy to tailor via a knob-switch-and-slider array that enables adjustment of effects blend, EQ, pre-delay, reverb time, pan position in a stereo field, and more. The input/output array is capable but straightforward, with stereo I/O, effects send and return, plus MIDI, USB, and expression-pedal capability.
Deep Diving
The individual reverb sounds in the Abyss are excellent, which, given my experience with previous Oceans-series reverb pedals, is what I would expect. The more complex factory presets range from weird-but-inspiring to verging on impractical. But the simpler reverbs exude elegance. Even the other built-in effects are incredible. I got delightfully lost in the bit crusher for some time, dialing in a very interesting and buzzy fuzz tone.
“The simpler reverbs exude elegance.”
The factory presets are great jumping-off spots and rewarding to use. But to take full advantage of the pedal’s capabilities—and, perhaps, to justify the lofty $495 price—you’ll need to spend significant time with the Abyss and its manual. Creating and editing presets (you can save up to 128) isn’t always intuitive. For many users, customization will be easier using the available desktop patch editor or the not-yet-available EHX patch editor app. Even power users may be hard-pressed to utilize all of the Abyss’ capabilities. I am anxious now, knowing that somewhere in my house the Oceans Abyss is flashing red—still signaling intolerance of my refusal to fully commit to a pre-delay time.
In name, function, and price, the Ocean’s Abyss is much more than its predecessor, Oceans 12. It’s seemingly infinite, endless in every direction. Whether it’s a fit for you will come down to your appetite for exploration and study, and the scale of your musical ambitions.
Declan Mehrtens and Gus Romer brought the heat for the punk quartet’s storming spring headline tour.
Australian punks Amyl and the Sniffers have had a pretty good year. In October 2024, they released their third full-length, Cartoon Darkness, and opened a run of North American shows for Foo Fighters. This year, they warmed up the stage for the Offspring for a handful of shows in Brazil, then tore off across the United States and Canada for a headlining tour.
Ahead of their stopover at Nashville’s Marathon Music Works, PG’s Chris Kies met with guitarist Declan Mehrtens and bassist Gus Romer to see what weapons the Aussie invaders are using to conquer the music world.
Mehrtens reckons he’s played around 300 gigs with this trusty Gibson Explorer, and it was used on just about every track on Cartoon Darkness. While recording, he equipped it with flatwound strings and a Lollar P-90 pickup in the bridge, but for tour, it’s got a Seymour Duncan Saturday Night Special in the bridge in addition to its stock neck pickup. It’s tuned a half-step down, and an identical (though less beat-up) Explorer is on hand in case this first one goes down.
Deluxe Dreams
This FenderTelecaster Deluxe comes out for the set’s softest song, “Big Dreams.”
Marshall and Friends
In addition to his beloved JCM800, Mehrtens is running a Hiwatt Custom 100, a model he discovered in Foo Fighters’ studio. Both are dialled in for a general-purpose rock tone, and an always-on Daredevil Drive-Bi, kept behind the stacks, runs into the Hiwatt to push it into breakup.
Declan Mehrtens’ Pedalboard
The jewel of Mehrtens’ board is his SoloDallas Schaffer Replica, famous for its recreation of Angus Young’s guitar tone. In addition, he runs a TC Electronic PolyTune 3 Noir, Electro-Harmonix Soul Food modded with LED diodes, MXR Micro Flanger, two MXR Carbon Copy Minis, and a Vox wah pedal. A switcher with six loops, built by Dave Friedman, manages the changes.
P for Punk
Romer plays this Fender Precision Bass, which is either a 2023 or 2024 model, though he insists the “P” in P bass stands for “punk.”
Three-Headed Beast
Romer’s signal is split into three channels: One split comes after his tuner, and runs clean to front-of-house, another channel runs direct and dirty from this Ampeg SVT Classic, and the last runs through his cabinet into a Sennheiser MD 421.
Gus Romer’s Pedalboard
Romer’s board, furnished with the help of Mehrtens, gets right to the point: It features a TC Electronic PolyTune 3, a Boss ODB-3, and an MXR Distortion+.
Looking for versatility without cranking a stadium-level rig?
In this video, PG contributor Tom Butwin puts three sub‑50-watt amplifiers to the test: the British‑voiced Suhr SL15, the mid‑’60s American‑style PRS Sonzera 20, and the gig‑ready solid‑state Blackstar Debut 50R. Tom explores the tones, features, and ideal use cases of all three amps—highlighting who they're best suited for and how they perform in different setups. Which one fits your playing style and needs?