[All models explained] UAFX amp pedals comprehensive guide! A comparison of features, reviews, and recommended uses

You may no longer need to carry the deep resonance and heavy cabinets of a tube amplifier onto the stage.

Universal Audio's UAFX Amp pedals put the feel of legendary amps, from vintage Fender Deluxe Reverbs to VOX AC30s, Marshall Plexis, and Mesa/Boogie Dual Rectifiers, right at your feet.

What's more, UA's unique dual DSP and precise cabinet/mic simulations make it easy to record directly into a PA or into a DAW."It's the real stack that's ringing."The reality is so incredible.

This article covers the entire amplifier lineup and provides a thorough explanation of the features, sound trends, and actual reviews of each model.

From clean-focused savvy enthusiasts to high-gain enthusiasts, we've got tips to help you choose the perfect one for your pedalboard.

What is the UAFX Amp Pedal Series?

Universal Audio's UAFX pedal series is a line of products that aims to recreate the authentic sound of vintage amps at your feet, using a high-performance dual-engine processor and UA's outstanding analog modeling technology.

The first three amp emulations were released in 2022, and the lineup has since expanded to include everything from classic tube amps to modern high-gain amps. Each one is modeled after a legendary real amp, and features a reproduction of the mic'd cabinet sound of recording studio quality. With the UAFX amp pedal, you can instantly get the amp tone you want for live performances or home recordings without having to prepare a large amp or microphone.

UAFX Amp & Pedal Series | A comprehensive guide to current models

Dream '65 Reverb Amplifier

The Dream '65 is a pedal that captures the sound of the Fender Deluxe Reverb that many guitarists love. You can recreate the famous tone of that American tube amp used by such great artists as Muddy Waters, The Beatles, and Elvis Costello at home or on stage.

The clean tone is lustrous and bold, and you'll be intoxicated by the twin reverb-like spring resonance and swaying vibrato. There is also a boost circuit and a modified model inside, so if you turn up the gain, you can get a sufficient drive sound without a distortion pedal.

It's the only "amp-in-box" pedal that can provide the realism of real tube reverb and vibrato to this extent. It can cover a wide range of genres, from soul, surf, and funk to punk, blues, and bebop.

Ruby '63 Top Boost Amplifier

Ruby '63 is a pedal that reproduces the sound of the VOX AC2, used by many famous bands such as The Beatles, Queen, and U30, at home or on your pedal board. With this one unit, you can experience everything from the brilliant clean tone that is unique to the AC30 and is described as "choir-like," to dense and complex overdrive sounds, and pulsating vibrato tremolo.

Thanks to the ample processing power of the dual engine DSP, the response and distortion are just like a tube amp. Another advantage of the Ruby is that you can switch between all three AC30 channels, Normal, Brilliant, and Vibrato, on the pedal. With just one switch, you can go from Irish clean to British crunch, and even Brian May-esque rich leads, giving you the feeling of "carrying around an entire amp."

You can also use the built-in boost effect to push the top boost channel even further to get a tight lead tone. From home recording to the stage, it will be your companion that gives off the flavor of British classic rock.

Woodrow '55 Instrument Amplifier

The Woodrow '55 is a pedal that reproduces the sound of the Fender Tweed Deluxe (made in 1955), which can be said to be the origin of guitar amplifiers. The rough yet warm tone of this small tweed combo amplifier has been loved by many guitarists, including Chuck Berry and Neil Young.

With this pedal, you can enjoy the crunch sound that is unique to vintage pedals to the fullest. If you turn up the volume, you can get a thick breakup distortion, and you can experience the comfort of controlling the clean to distortion by adjusting the guitar volume. Another thing to note is the additional cabinets that can be selected via the app. In addition to Woodrow's original 1x12 tweed cabinet, Bassman's 4x10 cabinet IR and Celestion's 4x12 cabinet IR are available, and depending on the combination, you can create a Fender Bassman-like clean tone or a thick Marshall JTM45-like distortion.

While it produces a "classy sound for connoisseurs" that will be irresistible to fans of vintage amps, it is also a versatile model that can also serve as the foundation for creating modern sounds when combined with boosters and pedals.

Lion '68 Super Lead Amp

Lion '68 is an amp pedal that condenses the sound of Marshall's legendary "Plexi" (100W model). Its clean sound is as lustrous as a bell, and when you turn up the volume it produces a rough crunch that pierces your ears, and when you turn it all the way up it produces a roaring distortion called the "brown sound."

What makes this pedal unique is that it contains three types of Plexi circuits in one unit. In Super Lead mode, you get the gorgeous, fat rock sound of the famous '3 Super Lead, in Super Bass mode, you get a sound with a wider clean headroom and a spongy attack (great with pedal boost), and in "Brown" mode, you get the legendary brown sound that EVH sought. These can be switched with a single foot switch, so you can instantly switch between a clean rhythm and a distorted lead, which is difficult to do with the actual unit, just like a channel switch.

Lion '68 is a carefully modeled version of a real amp known as the "golden specimen," so the level of reproduction is guaranteed. Whether you use it on stage instead of an amp by connecting it directly to a PA or record it in a DAW, it provides a full-stack sound with a realism that surpasses other digital models. This is because the dynamic speaker modeling technology derived from UA's OX Amp Top Box perfectly simulates the combination of six classic cabinets + room microphones. In addition, it is equipped with a noise gate function that is convenient for high gain, and keeps the sound crisp even in extreme settings. The built-in EP-III preamp as a classic boost and 6-band EQ allow you to fine-tune the sound by raising the mids during solos or pushing the distortion even further.

Knuckles '92 Rev F Dual Rec Amplifier

Knuckles '92 is an amp pedal that perfectly reproduces the Mesa Boogie Dual Rectifier sound that metal fans covet. You can get the tone of that high-gain amp (90W class) that once took the world by storm with its thick, scooped riff sound, from thrash metal and death metal to 120s alternative and nu metal, right at your fingertips in the comfort of your own home. It's amazing how it covers everything from thick bass and crisp attack to scorching lead tones to surprisingly clear clean tones, all in one unit.

What makes Knuckles great is that it not only distorts the sound, but also has a detailed sound-making function. It has a Tube Screamer-style overdrive circuit inside, which boosts the mids to accentuate fast leads and heavy riffs. Furthermore, by switching to preamp boost, you can increase the gain without cutting the deep bass to get a saturated sound like Scandinavian metal. The best part is the noise gate, which shuts out unnecessary feedback and hum even at ultra-high gain. Thanks to this, you can distort to your heart's content without noise stress when recording, and some people say, "The noise gate is a big help and is useful for recording."

The cabinet is also luxurious. It includes six classic 6x4 cabinets and standard microphone combinations, allowing you to reproduce the sounds heard on many classic albums from 12's hard rock to 70's metal. Furthermore, using the app, you can pursue even more esoteric settings, such as changing the power tube from 90L6 to EL6 and switching the rectification from diode to vacuum tube. This follows the functions of the real Dual Rectifier (34L6/EL6 switching and rectification mode switching), so you can enjoy the behavior changes just like the real thing. In short, the Knuckles '34 is a must-have pedal for metal/loud guitarists, as if it were a condensed version of the "high gain stack of that era."

Enigmatic '82 Overdrive Special Amp

The Enigmatic '82 is a pedal designed to let you enjoy the sound of the Dumble Overdrive Special, a legendary amplifier, at home. Its sound character is one of a kind, with a crystal-clear clean tone on the clean channel and a horn-like, smooth, singing overdrive on the OD channel. It's impressive to see the superb tones used by masters such as Steely Dan, Larry Carlton, and Robben Ford overflowing from this small unit.

The Enigmatic has two channels (clean and overdrive) and can be switched with a foot switch. The clean is easy to handle, from jazzy fullness to country-style crispness, and when switched to overdrive, it produces a sustained and lustrous lead tone. This pedal also incorporates the FET input circuit found on the actual Dumble machine, so if you feel that the gain is insufficient, you can raise the FET trim and use it as a clean boost. This allows you to make sounds that are more aggressive on the high gain side, so much so that some users felt that the distortion was deeper than they expected, which was a pleasant surprise. Another thing worth mentioning is that it has a very good sound and works well with pedals. It blends in easily even if you put other drive pedals in the front stage, making it a versatile Dumble that can accept pedals. In fact, it has been praised in reviews by specialist media as "it combines crystal clean and creamy overdrive, and is also excellent with pedals."

ANTI '92 High-Gain 5150 Amplifier

ANTI '92 is a UAFX pedal that faithfully emulates the "90 Block Letter" that dominated the high-gain world since the '5150s. It reproduces the rough saturation and tight low range that created the explosive riffs of Metallica's "Load" and Van Halen's "Balance" in a pedal-sized package.

The rhythm channel is already a thick distortion at around gain 3, and when it exceeds 5, it transforms into a lead tone that clings to the picking. The lead channel has even more compression, and single notes are extended like a horn. When the front-stage TS boost is turned on, the midrange is lifted and it quickly changes into a "fast playing specialized" sound for modern metal. The EQ section is as effective as the real thing, and you can freely go from 90's NU-Metal with a bold scoop of the middle to modern prog-metal with a push of the high mids.

All six IRs are recorded using UA OX technology, and the cab and microphone positions can be instantly changed using a smartphone app. By changing the rectification method and output tube to EL6, you can achieve a brighter, more British character, making this a high-gain all-purpose machine with more flexibility than the real thing.

Summary | Which UAFX amp is right for you?

Both models offer the high sound quality and craftsmanship that you expect from UA, so you can't go wrong.

Choose the one that's perfect for you based on your musical tastes, the guitar you use, and the purpose (live direct amp, home recording, etc.). With a UAFX amp pedal, the quality and convenience of your guitar sound will surely be raised to the next level!