Stompbox history is populated by crackpots and geniuses. But few pedal builders are as fit for inclusion in the latter category as Mike Beigel. In the early ’70s Beigel co-founded Musitronics, which built some of the most coveted and colorful effects ever conceived: the Mu-Tron Bi-Phase, the Mu-Tron Flanger and Phasor, the Vol-Wah, and the Mu-Tron III.
When Mu-Tron bit the dust (after acquisition by ARP in 1979) Beigel took his curiosity and engineering chops elsewhere—helping develop, among other things, miniscule radio-frequency ID chips to track animals. But like many instrument developers, Beigel found it hard to stay away from the biz. He marks his return with the Mu-FX Tru-Tron 3X, an enhanced version of the Mu-Tron III envelope filter.
World Beyond Wah
Even some seasoned players struggle to define the function of an envelope filter (also known as an auto-wah). Basically, it uses a voltage controlled frequency peak filter to emphasize a selectable frequency range. Meanwhile, an envelope follower triggers the effect in response to your playing dynamics.
Most players know the sound when they hear it—think Jerry Garcia’s bubbling mid-’70s leads, Bootsy Collins’ vocalic bass bombs, and Stevie Wonder’s funky clavinet on “Higher Ground.” All were created with an original Musitronics Mu-Tron III.
The optical filter control circuitry and control set of the Mu-Tron III is at the foundation of the Tru-Tron 3X. And though the Tru-Tron eschews the elegant and colorful look of the original in favor of a more contemporary, industrial appearance, the controls (if not the layout) will be familiar to anyone who’s used an original.
There are two mini-toggles for envelope drive and filter range. The envelope drive switch selects between rising (updrive) and dipping (down drive) voltage controlled frequency peak frequency sweep. (These simulate heel-to-toe and toe-to-heel wah action, respectively, only without the rocker pedal.) The filter range control shifts the filter drive range to high-frequency or low-frequency input. The mu control (labeled gain on the original) sets the gain level of the signal to the envelope follower and filter, determining the effect’s dynamic response. The peak knob the filter Q or emphasis of the frequency sweep, while the mode knob selects between low-, high-, and band-pass filters, plus a useful new mix mode that blends dry and filtered signal.
The most significant new features are the preamp knob and switch. The pre setting effectively splits the drive function, creating separate amplitudes for filter audio input and envelope sweep, expanding the palette of available sounds.
Vowels Spoken Vociferously
Like any envelope filter, the Tru-Tron relies on picking dynamics and input gain to determine how intensely the filter performs, so it can take a little practice to adjust the settings to suit your touch. (Soft pickers might benefit from higher mu settings, while more dynamic pickers and low output pickups might benefit from a lower one.) But once you’ve established an appropriate gain level, it’s easy to hear what makes this effect intoxicating for so many players.
Ratings
Pros:
Authentic Mu-Tron III tones. Independent filter gain for overdriven sounds. Excellent build quality.
Cons:
Miss that cool blue and silver enclosure! Not super-intuitive.
Tones:
Ease of Use:
Build/Design:
Value:
Street:
$295
Beigel Sound Lab/Mu-FX Tru-Tron 3X
mu-fx-trutron3x.com
Because the effect can completely alter the character of a single note, it’s well suited to concise, percussive, and melodic phrases. (Fast flurries tend to get messy, though lower peak settings and adjustments to an internal trim pot for response help make the pedal better suited to fast picking.) The Tru-Tron can transform a simple quarter- or eighth-note melody into something much more colorful. The pedal’s Garcia-inspired setting is great for exploring this capability. It uses the low-pass filter, which lends a deep, vocal quality to each note.
Changing the filter type has a profound effect on tone and dynamics. High-pass imparts an almost electric sitar-like flavor, with a slow-blooming and fast-decaying high-midrange tone. The band-pass filter tends to remove low end, producing rich but compact vowel-like tones ideal for doubling a bass line without muddying a mix. The mix setting, new on the Tru-Tron, blends in dry signal for a subtler effect. Like all the Tru-Tron’s controls, peak is sensitive and wide-ranging. High values work well for percussive, mid-tempo leads that leave room for the filter open and close between notes. Low to medium peak settings give notes more articulation.
Preamp is one of the most significant and unique Tru-Tron features. When switched on, it drives the filter independently from the envelope, enabling muscular, overdriven tones that work with the envelope more seamlessly and harmoniously than a fuzz, distortion, or overdrive would. This opens up a whole world of heavy soloing textures. These can be dynamic alternatives to phasing or flanging, and more unique-sounding than a wah sweep working a distorted tone.
The Verdict
The Tru-Tron 3X captures the deep, rich, vocal, expressiveness of the original Mu-Tron III (no mean feat) while adding enhancements that expand its potential. It’s a very powerful stompbox—and that’s before you factor in how well it works with bass and keys. It’s not for everyone, and some players enticed by the concept may lack patience for the experimentation the pedal demands. But for those willing to tinker, the Tru-Tron 3X can provide unexpected musical potential that extends far beyond the obvious Garcia and Bootsy-styled applications.
Watch the Review Demo:
Hotone Wong Press
Cory Wong Signature Volume/Wah/Expression Pedal
Renowned international funk guitar maestro and 63rd Grammy nominee Cory Wong is celebrated for his unique playing style and unmistakable crisp tone. Known for his expressive technique, he’s been acclaimed across the globe by all audiences for his unique blend of energy and soul. In 2022, Cory discovered the multi-functional Soul Press II pedal from Hotone and instantly fell in love. Since then, it has become his go-to pedal for live performances.
Now, two years later, the Hotone team has meticulously crafted the Wong Press, a pedal tailored specifically for Cory Wong. Building on the multi-functional design philosophy of the Soul Press series, this new pedal includes Cory’s custom requests: a signature blue and white color scheme, a customized volume pedal curve, an adjustable wah Q value range, and travel lights that indicate both pedal position and working mode.
Cory’s near-perfect pursuit of tone and pedal feel presented a significant challenge for our development team. After countless adjustments to the Q value range, Hotone engineers achieved the precise WAH tone Cory desired while minimizing the risk of accidental Q value changes affecting the sound. Additionally, based on Cory’s feedback, the volume control was fine-tuned for a smoother, more musical transition, enhancing the overall feel of volume swells. The team also upgraded the iconic travel lights of the Soul Press II to dual-color travel lights—blue for Wah mode and green for Volume mode—making live performances more intuitive and visually striking!
In line with the Hotone Design Inspiration philosophy, the Wong Press represents the perfect blend of design and inspiration. Now, musicians can channel their inner Cory Wong and enjoy the freedom and joy of playing with the Wong Press!
Reverend Vernon Reid Totem Series Electric Guitar - Shaman
Silos features six presets, tap tempo, one full second of delay time, and three voices—two of which are styled after bucket-brigade and tape-delay sounds. In the $150 price category, it’s not unusual for a digital delay to leave some number of those functions out. And spending the same money on a true-analog alternative usually means warm, enveloping sounds but limited functionality and delay time. Silos, improbably perhaps, offers a very elegant solution to this can’t-have-it-all dilemma in a U.S.-made effect.
A More Complete Cobbling Together
Silos’ utility is bolstered by a very unintimidating control set, which is streamlined and approachable. Three of those controls are dedicated to the same mix, time, and repeats controls you see on any delay. But saving a preset to one of the six spots on the rotary preset dial is as easy as holding the green/red illuminated button just below the mix and preset knobs. And you certainly won’t get lost in the weeds if you move to the 3-position toggle, which switches between a clear “digital” voice, darker “analog” voice, and a “tape” voice which is darker still.
“The three voices offer discernibly different response to gain devices.”
One might suspect that a tone control for the repeats offers similar functionality as the voice toggle switch. But while it’s true that the most obvious audible differences between digital, BBD, and tape delays are apparent in the relative fidelity and darkness of their echoes, the Silos’ three voices behave differently in ways that are more complex than lighter or duskier tonality. For instance, the digital voice will never exhibit runaway oscillation, even at maximum mix and repeat settings. Instead, repeats fade out after about six seconds (at the fastest time settings) or create sleepy layers of slow-decaying repeats that enhance detail in complex, sprawling, loop-like melodic phrases. The analog voice and tape voice, on the other hand, will happily feed back to psychotic extremes. Both also offer satisfying sensitivity to real-time, on-the-fly adjustments. For example, I was tickled with how I could generate Apocalypse Now helicopter-chop effects and fade them in and out of prominence as if they were approaching or receding in proximity—an effect made easier still if you assign an expression pedal to the mix control. This kind of interactivity is what makes analog machines like the Echoplex, Space Echo, and Memory Man transcend mere delay status, and the sensitivity and just-right resistance make the process of manipulating repeats endlessly engaging.
Doesn't Flinch at Filth
EarthQuaker makes a point of highlighting the Silos’ affinity for dirty and distorted sounds. I did not notice that it behaved light-years better than other delays in this regard. But the three voices most definitely offer discernibly different responses to gain devices. The super-clear first repeat in the digital mode lends clarity and melodic focus, even to hectic, unpredictable, fractured fuzzes. The analog voice, which EQD says is inspired by the tone makeup of a 1980s-vintage, Japan-made KMD bucket brigade echo, handles fuzz forgivingly inasmuch as its repeats fade warmly and evenly, but the strong midrange also keeps many overtones present as the echoes fade. The tape voice, which uses aMaestro Echoplex as its sonic inspiration, is distinctly dirtier and creates more nebulous undercurrents in the repeats. If you want to retain clarity in more melodic settings, it will create a warm glow around repeats at conservative levels. Push it, and it will summon thick, sometimes droning haze that makes a great backdrop for slower, simpler, and hooky psychedelic riffs.
In clean applications, this decay and tone profile lend the tape setting a spooky, foggy aura that suggests the cold vastness of outer space. The analog voice often displays an authentic BBD clickiness in clean repeats that’s sweet for underscoring rhythmic patterns, while the digital voice’s pronounced regularity adds a clockwork quality that supports more up-tempo, driving, electronic rhythms.
The Verdict
Silos’ combination of features seems like a very obvious and appealing one. But bringing it all together at just less than 150 bucks represents a smart, adept threading of the cost/feature needle.
EarthQuaker Devices Silos Multi-generational Time Reflection Delay Pedal
