“When in doubt, don’t.” It’s a pearl of wisdom that offends risk takers and guides more than a few tortoises to the finish line ahead of the rabbits. But in the tone-chasing world this dictum carries extra weight, because depending on your aims, anything you situate between guitar and amplifier can subtract as much as it adds. Indeed, a little restraint can go a long way toward sweetening a sound.
And restraint is one of the things that makes the ZEQD-Pre, a preamp co-designed by EarthQuaker and Mike Zaite (aka Dr. Z), such an elegant piece of kit. The things they didn’t add make it easier to use. The streamlined design also makes the ZEQD-Pre feel truly additive. It can lend body and excitement to big tube amps that sound flat at low volume. And as an analog addition to digital signal chains, it adds real life and a tactile dimension to flat, drab, or spiky DAW and modeler tones.
Feel Free With The Help Of A Pre
Though the ZEQD-Pre is a beautifully integrated whole, it’s effectively made up of two sections. There’s a passive EQ that can do a lot on its own to recast or fine tune the sound of a tube amp or modeler. It also features a boost. Switching on the boost disengages the EQ. But both sections use the level control as an output volume control.
In my first experiments with the ZEQD-Pre, I situated it in front of a 50-watt Fender Bassman and 2x12 cabinet. And though I suspect more potential customers will be interested in the EarthQuaker’s potential in digital environments, it can transform conventional tube amplifiers. I rarely get to turn my Bassman up much past 2 in my house. But the ZEQD-Pre’s EQ section made those modest volumes sound much fuller. The boost is not a high-gain affair, but it adds weight and excites overtones that might otherwise lay dormant at low volume. At higher amp volumes it can add a just-right nudge into the dirty zone that almost always sounds silky rather than harsh.
EarthQuaker Devices ZEQD-Pre Preamp Demo
“It is zingy, responsive, and does much to take away the uncanny valley sense of lifelessness you can feel when interacting with a modeler.”
Use of the EF86 in a preamp is not common—at least relative to the ubiquitous 12AX7. But Dr. Z’s choice of the EF86 for the boost is an inspired one. It is zingy, responsive, and does much to take away the uncanny valley sense of lifelessness you can feel when interacting with a modeler. Those that know the EF86 by its too-hot-to-tame reputation needn’t fear that it will be a handful though. The ZEQD-Pre boost voice is balanced and lively in all the right ways, and these attributes are especially apparent when the pedal is paired with a digital end destination.
When testing the ZEQD-Pre in this capacity—by running a cable from the headphone output straight into the Hi-Z input of my Universal Apollo Twin—I did not make it easy on the EarthQuaker. My main instruments are Jaguars and Jazzmasters, and the relatively thin and trebly output from both of them rarely flatters modeled and DI sounds. But I really liked the tones that I tracked with just the ZEQD-Pre and the DAW—especially without a modeled amp in the mix. The EQ adds body and tone-shaping versatility, and the boost lends real character and color, inhabiting a sweet space that is neither Fender Princeton nor Vox AC15, but which possess some of the smooth richness of the former and the sparkle of the latter. I enjoyed the sound of the ZEQD-Pre direct into the Apollo so much that it ceased to feel like a compromise between amp and modeler. Instead, it felt like something unique—an amp with its own very appealing flavor that I would use for its sonic virtues as much as its convenience.
The Verdict
Though I’ll opt for a tube amp in almost any situation where there is a choice, I’ve warmed to some of our faux-amp friends in the digital domain. That said, I think I would choose the ZEQD-Pre and my pedals over almost any modeler. In direct-to-DAW situations, the ZEQD-Pre is warm, alive, and sounds, well, a lot like a real amp. It also feels like it was designed by people that know how a tube amp should feel under the fingers and in a room.
The ZEQD-Pre makes distortion and fuzz units sound like their real selves. And even without a simulated power amp, the cab sim makes rigs sound great through flat response monitors. The ZEQD is nearly $400, and for most of us, that’s a hefty enough sum to give pause. But the U.S.-made ZEQD-Pre is designed by gifted builders that have poked around the innards of amps and stompboxes for years and built classics in their respective fields. So, you can rest assured that the bars this pedal needed to clear in sonic and quality terms are high ones. I was pleasantly surprised and impressed—to the point where $399 seemed a very reasonable price to pay. And if you’re a tube amp loyalist navigating the worlds of backline-free gigging and digital recording, you may end up similarly smitten.
This month's roundup features 15 essential releases, including EarthQuaker Devices’ all-analog tube preamp, Red Panda’s new pitch delay, and a studio-grade line isolator from Lehle. Whether you need vintage grit or modern precision, we’ve got the highlights.
Chicago Music Exchange
Fender Player II Lavender Haze Collection
Chicago Music Exchange and Andertons introduce their latest exclusive: Lavender Haze—a Player II collection that looks like a lost custom color from Fender’s golden era and sounds bigger, warmer, and more powerful than ever. Each instrument is loaded with exclusive “Full Dip” pickups, upgraded wiring mods, and thoughtful vintage-inspired details.
Nobels’ new mini pedals all feature tap tempo, mono or stereo (TRS), and true- or buffered-bypass switching. Each model offers 3 modes: MOD-mini has tremolo, phase, and u-vibe; CHO-mini has chorus 1, chorus 2, and flanger; DEL-mini tape, analog, and digital. Lots of features, great value!
Building on the legacy of the StroboStomp HD, the view-only StroboVUE delivers Peterson’s renowned strobe accuracy in an always-on pedalboard format. Its angled, high-visibility display and fully top-mounted jacks keep setups clean. Featuring pure buffered output, continuous tuning feedback, and no mute switch, StroboVUE is built for players who demand precision.
Dial in the past with the tilt EQ to create vintage bucket brigade tones, or dial it the opposite way to achieve classic ’80s sounds. The Aqueous features a preamp for gain makeup to limit the input and brings the circuit to life.
This all-analog tube preamp, designed with Dr. Z Amplification, features a real EF86 pentode tube to deliver authentic warmth and touch-sensitive response. This end-of-chain solution includes a three-band EQ, independent boost, analog cabinet simulation, and XLR/headphone outputs—perfect for direct recording or pedalboard-based rigs.
Do you want complete control of your overdrive? Kernom Ridge preserves your pure analog tone while unlocking the power of digital control. Its patented Analog Morphing Core sweeps smoothly from edge-of-breakup to saturated lead and every drive tone in between. Save presets, use MIDI or expression, and command your tone.
This stereo line isolator brings you closer to the main system. Passively, it converts your stereo audio signal not only to balanced XLR but lifts the ground so there’s no chance of noise or hum. Perfect for pedalboards or modeler, live or studio—all fitted into a handy size.
This focused digital delay features integrated pitch and frequency shifting designed for immediate, hands-on control. Shift repeats once or endlessly in the feedback loop, from clean delays to subtly twisted textures and out-there sounds.
The Dirt Dog Overdrive—developed with Joey Landreth—delivers expressive, amp-like breakup with outstanding touch sensitivity. Simple gain, level, bite, and tone controls make it easy to shape everything from warm grit to rich, sustaining drive.
This bold cross-border collab takes Summer School Electronics’ DS-1-inspired buzzsaw distortion and smashes into Supercool Pedals’ watery Small Clone chorus to create unmistakable grunge tones. With a chain-order switch in tow and art soaked in ’90s lore, it’s a blistering love letter to an iconic sound.
This boutique, Klon-style overdrive pedal is now fully built and ready to play. Get rich, transparent drive, smooth sustain, and dynamic response without building the kit yourself. Perfect for adding warm grit or pushing your amp into singing lead tones.
The StewMac Two Kings, based on the Analog Man King of Tone, packs two legendary overdrive circuits into one fully built pedal, no soldering required. From transparent boost to rich mid-gain crunch, stack the drives for endless tonal options. Perfect for shaping your rhythm tone or adding singing sustain to solos.
This fully assembled, board-ready analog phaser pedal was inspired by the legendary Mu-Tron Phasor II. Featuring lush, sweeping modulation, rich vintage tone, and three intuitive controls for rate, depth, and feedback, it effortlessly delivers anything from subtle movement to deep, psychedelic swirls—no assembly required.
A boutique-style pedal inspired by the Analog Man Sun Face, fully built and board-ready. The Sun Fuzz delivers rich, touch-sensitive fuzz tones with warmth, clarity, and adjustability. Featuring silicon-based circuitry with internal bias and clean blend controls for tonal finesse, it handles thick chords and saturated leads equally well.
When Japanese engineer Susumu Tamura designed the Maxon OD808 overdrive, he could hardly have known that it and its export twin, the Ibanez TS808 Tube Screamer, would become perhaps the most influential and, probably, imitated pedals in stomp box history. In fact, upon its introduction in 1979, the Tube Screamer, whose smooth sound is characterized by a bass roll off, midrange bump, and slight high-end attenuation, was not an instant success. But as the pedal was adopted by players as disparate as Stevie Ray Vaughan and Kirk Hammett, it gradually became a ubiquitous presence on pedalboards of all persuasions.
Tumura, a guitarist himself, spent several of the intervening decades working on wireless designs. In recent years, however, he began modifying Tube Screamers for Japanese guitar stores. But now in his seventies, he found the pace—almost 1,000 pedals annually—exhausting. Why not, he thought, just make a pedal that incorporated all his refinements? Enter the TWA SC-01 Source Code, which is exactly that. Handmade in the U.S., the SC-01 features improvements on the TS design, including 18V operation via an internal regulator, a +6 dB boost, anop amp that claims toinject “complex harmonics and an amp-like feel,” and, most importantly, a “Bite” control that can mix in asymmetrical, tube-like clipping to the symmetrical clipping-based sound of the original.
Source in Session
Using a Stratocaster and Fender Princeton Reverb as my test platform—a made-for-Tube Screamer rig if there ever was one—I first determined whether the Source Code could speak traditional Tube Screamer by A/B-ing it with a recent Ibanez TS-9 reissue. It does, producing tones indistinguishable from the traditional circuit when the bite control is at zero. That said, if your take on Tube Screamers has always been, “if it could only just…,” you’ll find that the bite knob opens up a whole new world. Goosing it adds the extra measure of sizzle, zing, and teeth that more common iterations of the design always lacked. And adjusting the balance of the drive and bite controls dials in an enhanced and expanded range of overdrive tones that truly transcend the original TS.
The Verdict
Whether you deploy Susumu Tamura’s latest refinement of the TS circuit to hit the input of an amp that’s already breaking up or as your primary source of overdrive, you won’t be disappointed. It offers all the essence of the original, but it’s the extra oomph and range that impresses.
Running two effects of the same kind concurrently can yield amazing results. Stacked fuzzes or RATs? I’m in heaven. Other effects work less reliably well in pairs. Two reverbs, for instance, can sound killer but can turn an otherwise carefully crafted signal to smog. Twin phasers, in my experience, can be counted among the effects that are delicious together. It takes just two simple one-knob phasers to get very weird. Build two phasers into one, though, and add a few extra tone shaping controls, and the weird gets weirder fast.
Keeley’s new U.S.-made, digital Oaxa twin phaser can feel nearly as simple and straight ahead as two Small Stones running side by side, and honors the elegance and ease of that solution in many ways. There’s just three knobs—for rate, feedback, and depth. A small 3-position toggle switches between 10-stage phase, 4-stage phase, and a Uni-Vibe-style mode. Two footswitches select between the individual phaser or a combination of the two. If you want to keep things simple, you can dive in no further than that and have a great time. But Oaxa bears many secrets for deeper diggers.
Working the Waves
The phase effect is fun to use intuitively. And adding it in and out can be low stakes. Feeling that a riff sounds lifeless? Add a phaser and twist the rate. Maybe it’ll be exactly what a song needs. Maybe it will sit like rotten mayonnaise. But it won’t have taken much effort to try, and you’ll probably have fun along the way. The Oaxa is deeply satisfying in this manner.
The brilliant, big rate knob can be adjusted with precision using just a toe (provided you have the right shoes). And while the depth and feedback controls might be an affront to Phase 90 and Small Stone users, Oaxa’s controls open up useful phase possibilities without leaving you feeling doomed to get lost in the weeds. The depth control, for instance, has so much range it can render the phaser all but subliminal—making it a killer always-on sweetener that can be nudged in and out of prominence via the depth knob. Those just-barely-there depth settings can also be subtly re-shaped by the similarly rangey feedback control, which acts like a filter, adding wah-like focus at mild depth. At more intense depths, the feedback adds appreciably more vowelly “wow” tonalities that give Oaxa more than a hint of a Mu-Tron’s beautiful vintage essence. This variation—and interactivity—among depth and feedback colors alone makes Oaxa a great production, arrangement, and guitar layering tool, particularly in spacious arrangements.
Bear in mind that all the phase phenomena I’ve described here were observed in the 4-stage phaser voice—my most natural and familiar phase space. But the 3-way toggle can also be configured for 10-stage voicing or as a Uni-Vibe-style phase effect. The 10-stage voice is a little more binary than the 4-stage, and can obscure some overtone nuance in the wash. At extreme depth settings it can even sound almost tremolo-like. For a lot of players, the more focused modulation waves in the 10-stage voice will be a perfect fit for rhythmic delays or staccato passages begging for a little extra wobble and a more interesting tail. The Uni-Vibe style setting, meanwhile, is a pretty authentic version of the effect and delivers a recognizable take on the drippy “whoop”-like phase created by a Uni-Vibe’s optical circuit. Like the real deal, it sounds fantastic with fuzz.
Multiplied by Two ... and More
When both phasers are on, Oaxa’s jewel lamp flashes blue and red, and the visual suggestion of a party is apt. There are deep and crazy sounds here that can take you deep into the wee hours. But not all combinations are magic. Certain pairings of modulation rate and harmonic peaks can obscure details that might make a single phase voice pleasing. But the option to run the two phasers in parallel or series enables more or less detailed versions of a compound phaser voice, respectively. And just-right phase-rate relationships combined with contrasting voices, depth, and feedback can yield fantastic results. Fast-throbbing U-Vibe style modulations combined with slow, deep 4-stage phases are extra dimensional—as are just about any two high-contrast rates. Nailing these combinations and hearing them via stereo—the other great force multiplier on Oaxa—can pull you deeper still into the pedal’s capacities.
The Verdict
Do you remember what I said at the top about the Oaxa being simple? It’s true. It’s just that Oaxa’s elegant design also has a lot in store for troublemakers willing to dig a bit. And if the stereo and dual-phase settings aren’t trouble enough, you can use the footswitches and knobs to introduce compression or extra filtering, or reconfigure the toggle to include 2- and 6-stage phaser voices. I’d venture that using the most basic functions will make the $199 price well worth it over time. But you’ll likely celebrate the day you stumble across one of Oaxa’s more complex finds. I suspect such days will be many in number, too.
Any effect can color a guitar’s personality and language. But Boss’ new XS-1 Poly Shifter literally stretches the instrument’s vocal range. With the ability to shift input by +/-3 octaves or semitones, it can turn your guitar into a bass, a synth, or a baritone, or function as a capo. It also seamlessly generates harmonies for single note leads and keeps up with quick picking without any apparent latency. Furthermore, the pedal is capable of stranger fare that stokes many out-of-the-box ideas. But if you’re a guitarist that plays more than one role in your band—or musical life in general—the XS-1 can be a utilitarian multitool, too. It’s a pedal that can live many lives.
- YouTube
The XS-1, which was released alongside its bigger, more intricate sibling, the XS-100, is an accessible route to exploring pitch shifting’s potential. Housed in a standard Boss enclosure, it doesn’t consume a lot of floor space like the XS-100 or DigiTech’s Whammy. And while it achieves this spatial economy in part by forgoing a built-in expression pedal (which could be a deal breaker for some potential customers) it’s still capable of +/- seven semitones and a +/- three-octave range that can be utilized in momentary or latching applications.
Slipping, Sliding, and Twitching
Though digital pitch shifters have always been capable of amazing things, early ones sounded very inorganic at times. High-octave sounds in particular could come across as artificial, like the yip of a robot chihuahua plagued by metal fleas. Some very creative players use these colors—as well as the most sonorous pitch shift tones—to great effect (Nels Cline and Johnny Greenwood’s alien tonalities come to mind). In other settings, though, these older pitch devices can be downright cringey.
“The pedal clearly represents several leaps forward from first-generation pitch shifters.”
The XS-1 belies digitalness in some octave-up situations. But the pedal clearly represents several leaps forward from first-generation pitch shifters. Tracking is excellent and shines in string bending situations. Semitone shifts can provide focused harmony or provocative dissonance depending on the wet/dry mix and which semitones clash or sing against the dry signal. At many settings the XS-1 feels alive and organic, too, with legato lines taking on many of the touch characteristics of a violin-family instrument. You get far less of a note-to-note “hiccup,” and glissandos take on a beautifully fluid feel—with or without a slide—letting the XS-1 deliver convincing pedal- and lap-steel-style textures when you add a single octave up. (Such applications sound especially convincing when you kick back on guitar tone and restrict your fretwork to the 3rd through 5th strings, which keeps digital artifacts at bay.)
Mixmaster Required
The most crucial XS-1 control is the mix. For the most convincing bass, baritone, and 12-string tones, you’ll want a fully wet signal. But composite sounds can be awesome, too. You can use the control’s excellent sensitivity and range to highlight or fine tune the prominence of a consonant harmony. But it’s sensitive enough to make blends with dissonant harmonies sound a lot more intentional and integrated. And many of these eerie, wonky, off-balance textures are extra effective when introduced in quick bursts via the momentary switch. (That switch can also deliver great flashes of drama with more consonant harmonies—like dropping in a 3rd or 5th above a resolving chord in a verse.)
You can get creative in other ways using dissonant blends. Droney open tunings can yield fields of overtones that sound extra fascinating with delay, reverb, or 12-string guitar… or all of them! Dialing in blends that really work takes some trial and error, and you’ll definitely hit a few awkward moments if you’re navigating by instinct alone. But those same experiments often uncover real gems—especially in the pitch-down modes, which tend to produce more mysteriously atmospheric textures than their pitch-up counterparts.
The Verdict
Boss’ most straightforward pitch shifter covers a lot of ground. If you play in a duo, trio, or small band, it can expand that collective’s stylistic and harmonic range. It’s small, at least relative to treadle-equipped pitch shifters, so if you’re not a pitch shift power user, you don’t sacrifice a lot of room for an effect you might only employ occasionally, and you can still use the expression pedal jack to hook up a pedal for dynamic pitch control. The $199 price puts it in line with competitors of similar size and feature sets, but the XS-1 is a great value compared to more elaborate, treadle-equipped pitch shifters. If you’re taking your first forays into pitch shifting, or know that you need only the most straightforward functions here, it will ably return the investment. And along the way, it might even unlock a whole cache of unexpected tonal discoveries.
