Grissom and Paul Reed Smith’s first collaboration appeared in 2007 in the shape of theGrissom DGT—a signature instrument that’s seenmany iterations since. His Custom 30 amplifier followed five years later. But at 30 watts, that amp is pretty powerful for a lot of folks. So, this year PRS and their lead amp designer, Doug Sewell, unveiled the more club-friendly, tremolo-equipped DGT 15.
The basic architecture of the Indonesia-built DGT 15—single-channel, 2 x EL84 power section, 15 watts, and onboard reverb and tremolo—bears more than a little resemblance to a few important ’60s combo amps. But its 3-band EQ with presence, top-cut, and bright boost controls lends a lot of additional functionality and flexibility without cluttering the control panel or the playing experience. And, unlike some classic amps in this power class, the DGT 15 generates its wallop from a pair of output tubes in cathode bias, driven by three 12AX7s and one 12AT7 in the front end.
Feature Length
If the DGT 15’s control set were made up of just the EQ, presence, and top-cut controls, it would offer impressive tone-sculpting power. But the 3-way bright, boost, and master volume switches add exponentially more colors and gain contrasts. The bright switch is clever. It can be switched to always-on mode or set to disengage when the boost is on. The footswitchable boost, meanwhile, gives the single-channel DGT-15 the flex of a two-channel amp with a lead mode. Better still, you can set the amp up so you can activate the boost and master volume together—enabling access to the most headroom with the boost off and keeping the gain from running wild when the boost is engaged. The tremolo, too, can be activated via a mini-toggle or the included footswitch.
“While it’s basically clear, round, and full, depending on where you set the powerful EQ controls, you can reshape those tones into chunky, chiming, or sparkly variations on the clean theme.”Because the DGT-15 is cathode biased, the output tubes require no re-biasing when you change them. But the back panel includes jacks for monitoring bias levels, which is handy for matching tubes or diagnosing possible issues. The back panel is also home to the 5-pin DIN footswitch jack and three speaker outs for various combinations of 4 ohm, 8 ohm, or 16 ohm cabs. Our test unit came with the ported-back PRS DG 1x12 cabinet, which is loaded with one 60-watt Celestion Vintage 30. The DGT 15 head itself is a little bigger than lunchbox-sized (unless you’ve got a particularly hefty appetite). But it’s still an easy load at just 17.25" x 9" x 9.25" and a hair under 20 pounds. The 1x12" cab is relatively compact too, at 24" x 22.18" x 10.5", and weighs 27 pounds.
Tejas Tone!
If you read only the specs for the DGT 15 (or never had the pleasure of playing a Custom 30), you’ll probably expect a British voice. But the DGT 15’s core tonality leans as much toward the 1960s black-panel Fender camp, and it has a ready-to-rumble personality that shines through whether you match it to an ES-355 or a Telecaster.
With Fender single-coils in the mix, non-boosted settings are very clean right up to around 3 o’clock on the volume, where the amp starts to edge into breakup just a little. That’s a lot of clean room to roam. But while it’s basically clear, round, and full, depending on where you set the powerful EQ controls you can reshape those tones into chunky, chiming, or sparkly variations on the clean theme. Humbuckers push the DGT 15 to juicier, crunchier zones much sooner, of course. Even so, the amp remains crisp and taut without going muddy. With both single-coils and humbuckers, the overdrive and saturation generated by the boost avoid the sizzly sounds you hear from many modern lead channels and overdrives. It’s also very dynamic—easing into light distortion when you pick hard, and shedding its aggressive edge when you use a light touch or reduce guitar volume. Overdrive pedals (in this case, a Klon-like Wampler Tumnus Deluxe, Marshall-style Friedman Small Box, and a multi-voiced Tsakalis Six) gel with both the boost and clean modes, too. The reverb and tremolo are superb. The range of both successfully spans subtle and more radical sounds—and between these, a couple of drive pedals, and the Boost function, a gigging guitarist can wrangle a lot of flexibility out of this amp.
The Verdict
Using the single-channel, 2 x EL84/reverb/tremolo architecture as a jumping-off point, the DGT 15 scales new heights of versatility—not just via flexible switching and tone-shaping power, but by melding Vox-y edge with Fender clarity and body at a very accessible price.
The CHI was designed as an easily portable amp that Lifeson can reach for when a last-minute show pops up. It’s ostensibly “Marshall-y” in attitude, though it’s also very much a modern-voiced circuit with footswitchable clean and lead channels. It generates 30 watts via two 6L6EH output tubes and three 12AX7s in the preamp and phase-inverter stages. It’s a straight-ahead amp, wonderfully free of excess features to throw you off course. And while it's perfect for the diehard Rush fan (manual-suggested settings for several Lifeson signature tones, including “Limelight,” “Fly by Night,” and “Working Man,” confirm as much), there’s plenty here to satisfy guitarists outside the Canadian prog-rock obsessives club.
Greek to Me
The CHI exudes a businesslike demeanor, but it’s also stylish enough to stand apart from the scores of lookalike classic clones out there, dressed up as it is in race-grey levant vinyl, red-garnet piping, and black-matrix grille cloth. The logo panel sports a striking red font inspired by the text on the iconic Moving Pictures album cover, and the control panel carries an etched Starman graphic that lights up red when you flip the power switch (there’s no standby on this model). The 24" x 20" x 9", 49-pound amp, with its Baltic birch cabinet, feels solid and substantial, too. Mojotone’s reputation for quality cabinets extends back further than its amplifier business, and the company has supplied many top boutique amp builders. It’s easy to imagine why.
“Access to the fluid, singing tones that define much of Lifeson’s playing with Rush is easy.”
Controls include input gain, lead master, output master, treble, middle, bass, and presence, and there’s a pull switch for a “rhythm clip” function on the input gain, which adds a little dirt to erstwhile clean tones. Around back, you’ll find a jack for the single-button footswitch, a send and return for the effects loop, two 8-ohm speaker outs, and a single 16-ohm out. Inside, the CHI’s circuit is wired across a primary printed circuit board. Three smaller boards host output-tube connections, effects send/return and speaker outs, and the LED array that lights up the Starman. Workmanship is tidy throughout, with neat wire runs and tube sockets that are bolted to the chassis for support in addition to their connections to the respective PCBs.
The CHI’s 30-watt rating comes courtesy of cathode-biased 6L6s. The configuration slightly reins the power from these tubes, which can produce around 45 watts in a fixed-bias configuration, but they can often sound a little juicier and more harmonically complex when cathode biased. The setup also means you can replace the output tubes without having to reset their bias. (We will say, though, be careful when removing or reaching behind the amp’s upper-back panel: A sharp edge on the roughly cut protective screen left this reviewer with a slice on my index finger.)
A Ride in the Red Barchetta
Tested with a Gibson ES-355 and a Fender 1956 Stratocaster Reissue, the Lerxst CHI swiftly revealed itself as a versatile performer—able to do far more than the expected Lifeson-alike tricks that would appear to be its raison d’etre. Going straight to the gained-up lead channel with input gain set at 2 o’clock or more—a route that’s hard to resist on an amp like this—accesses a boatload of muscular grind, sustain, and sizzle. Attaining the fluid, singing tones that define much of Lifeson’s playing with Rush is easy. Dial down the input gain to noon or below, though, and you can tap into plenty of earthy, rootsy rock ‘n’ roll tones. A little tweak here and there delivers everything from gritty classic rock to dirty blues to gnarly garage-rock tones.
Rhythm channel tones will stay relatively clean at pretty hot settings, so you can play loud without sounding muddy. This capability will be a boon for texturalists who need headroom for detailed time-based and modulation effects. But the rhythm channel also works great with overdrive pedals (a TS10 Tube Screamer and Wampler Tumnus Deluxe both sounded excellent). Pulling out the input gain knob for rhythm clip is also an effective tool for adding dirt to the rhythm foundation. The overall level drops slightly, too, but since it’s not a footswitchable function you’re more likely to use this very practical mode with its own gain settings.
With that in mind, it’s worth noting that the CHI’s gain staging, and the knobs that control it, take some getting used to. Since input gain controls the drive level for both channels, you’re tied to finding a compromise between them, then balancing the lead output via the lead master control, and the overall volume of both channels at the output master. Including just one more knob to allow for both rhythm gain and lead gain controls would be more intuitive. As it is, the setup certainly works once you get the hang of it, and both channels can sound great, but it sometimes requires a little deviation from your ideal tone on one channel or another.
The Verdict
The Lerxst CHI combo is a convenient, versatile amp with more than enough punching power to keep up with a heavy drummer, and still sounds great when reined in to basement practice levels. While saturated rock sizzle is very much its forte, the medium-grind overdrive tones are appealing, and both cleans and clipped settings on the rhythm channel are useful and satisfying. Independent rhythm and lead gain controls would have been a plus, but the CHI combo has much to offer just as it is, whether you’re a Rush fan or not
