This downsized version of Marshall’s first amp still spans a sweet range of British and American tones and packs a punch—even in its 5-watt mode.
A well-designed, ruggedly built, and downsized update of the classic JTM45 platform. Suited for contemporary club and studio needs. Five-watt mode sounds excellent. Spans classic Brit and American tones.
Expensive for a 20-watt PCB-based combo.
Marshall JTM Studio ST20C
Marshall ventured ably into smaller and quieter realms with 2018’s Studio Series, which reduced the plexi, JCM, and Jubilee platforms down to a much more manageable 20 watts. The JTM45 is the latest Marshall legend to undergo the shrink treatment—yielding the Studio JTM ST20C, a 20-watt, 1x12 combo that harnesses big-bottle, 5881 output tube power in an amp suited for modestly sized clubs and studios.
Built from Tweed for Extra Speed
Though rightly recognized as one of the most significant amps of the 1960s, the JTM45 can confound casual Marshall enthusiasts with modern, high-gain leanings. It effectively mirrored the Fender 5F6A tweed Bassman circuit. But small differences between the amps (as well as bigger ones, like the Marshall’s Celestion speakers) added up to a unique and powerful voice perfectly suited for the emerging British blues-rock language.
To reduce the 30 to 40 watts produced by a JTM45 (depending on spec and era) to 20 watts while using the same 5881 power tubes the JTM45 was born with, Marshall uses a cathode-biased output stage and hits the tubes with lower voltages than big Marshalls run on. The circuit also enables the ST20C, and its sibling the ST20H head, to run even quieter via a 5-watt mode. It comes with contemporary niceties like an effects loop with bypass switch, a DI output, and speaker outs for 4-ohm, 8-ohm, and 16-ohm loads. But the ST20C is still a very old-school, all-tube creation at heart, using three ECC83 (Brit-speak for 12AX7) preamp and phase-inverter tubes, just like its predecessors.
Coffin It Up
Like the Bassman-inspired JTM45, the ST20C is what Marshall calls a two-voice amp, with shared EQ and two inputs per voice. Marshall’s numbering scheme for the inputs can be a little confusing to the uninitiated (they read “2” and “1” from left to right), but the top two inputs are for the high-output voice, the two below are for the low power voice. In each voice, input 2, aka the normal input, is the warmer and rounder-sounding of the two. Input 1, or the high treble input, brighter and snarlier. Each has its own loudness control, but they share treble, middle, and bass controls, as well as a presence knob that further tweaks high-end response at the output stage. The two voices can also be jumpered to access blends of input 2’s warmth and input 1’s brightness.
“Newbies might be surprised to hear how much the ST20C deviates from a modern definition of the Marshall sound.”
In addition to the vintage-evocative control panel, Marshall went all-out on the early JTM-era cosmetics for the ST20C, and I think it looks fantastic. The black levant covering is complemented by gold string and piping, fawn fret cloth for the grille, and an art deco “coffin” logo with red enamel “Marshall” text. Construction of the 19.7" x 18.1" x 10.4" birch-ply cabinet feels robust, and with the 16-ohm Celestion G12M Creamback speaker, it still weighs just around 39 pounds.
The Studio Series amps aren’t among Marshall’s handwired offerings, so the circuit inside is PCB. Nevertheless, it looks sturdy and well-built. The use of relatively low voltages in the output stage means the 5881 tubes should last longer than they would in a higher-wattage, higher-voltage amp. But if you do need to replace them, the cathode-biased configuration means you just pop in a new pair of 5881s and go—there’s no bias adjustment necessary.
Breaking in, Breaking Through
I checked out the ST20C with a 1959 Les Paul Reissue to see how it handled the classic Bluesbreaker formula, as well as a 1966 Fender Telecaster. With each guitar, it delivered a wide and expressive range of tones that are very much in keeping with the original’s performance. Newbies might be surprised to hear how much the ST20C deviates from a modern definition of the Marshall sound. But it is surprisingly versatile for that reason. And you can make the case that the ST20C tone palette works for a greater range of playing styles and genres than the average blaring stack.
The core tone is characterized by a thick, round midrange; silky, clear highs that aren’t piercing; and low-end tones that are full, round, and a little loose when you push it. The amp also works beautifully with overdrive pedals. A Tube Screamer sounded great, and a Marshall-style Friedman Small Box overdrive effectively brought out the ST20C’s plexi side. The effects loop works perfectly for time-based and modulation effects. Meanwhile, the 5-watt power setting rips without any significant tone loss.
Many players more familiar with the plexi and JCM800 Marshalls will be surprised by, well, how Fender-y the ST20C can sound. Obviously, the tweed Bassman-derived blueprint accounts for some of that. But if you’ve ever turned up an early-’60s, brown-panel Fender Deluxe and thought, “wow, that sounds like a mini Marshall!” … you’ll recognize that hybrid sound in many of the ST20C’s sweet spots, too. Crank it up and it’s raw, throaty, and singing like an early Marshall should be. Play it at the edge of breakup and it evokes more American-style tones. The ST20C’s ability to span these sounds and assert its own personality makes it a fun, flexible and inspirational piece of gear.
The JTM ST20C is an awesome addition to Marshall’s popular Studio Series and it’s cool to hear the tonalities of the company’s first amplifier rendered in such compact, practical form. Some buyers might find the near-$2K price tag high for a PCB-based, 20-watt amp. But when you consider the wide range of genres and styles this compact U.K.-built combo covers, and how assertive and primed to conquer it can sound and feel, it starts to sound like money well spent.
Marshall Studio JTM ST20C Demo | First Look
These intergalactic GMO mutants honor two things: metal and cheeseburgers. See how Earthly gear guideposts Iommi and Butler influence their tasty setups.
If you were to ask my wife, “What two things sum up Chris?” … she’d likely respond with “grilled meats and heavy metal.” So, given the chance to interview the self-appointed (and unchallenged) founders of “Drive-Thru Metal” that solidified their crispy claim with classic cuts “Frying Pan,” “Sweet Beef,” and “Pair-a-Buns,” I ordered a full plate.
The thing is, you don’t just interview guitarist Slayer MacCheeze and bassist Grimalice. Not because they’re from the “bowels of outer space” and don’t speak or understand English. They converse quite well. But these seasoned freaks don’t do anything for free. Everything’s on the menu and it’s all for sale. Thankfully, minutes before doors opened at Nashville’s longstanding rock beacon, Exit/In, Mac Sabbath’s techs Bill Woodcock and Jonathan Hischke summarized their monster masters’ tangy tone tools. The flash-fried, seedy conversation quickly taps some key signature gear of another Sabbath that equally sweetens and thickens the band’s sound like a condensed and chilled milkshake. Plus, there’s a story about how one fateful Black Friday deal provided an iconic, golden-arch bass. Here’s to a fun-hearted Rundown with the Milky Way marauders that fight back against stale food and rotten riffs. And by the end, we bet you’ll be saying “I’m loving it.”
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“I don’t know much about these guitars, but legend has it, Slayer MacCheeze came through the time-space continuum with a guitar in each hand,” states MacCheeze tech Bill Woodcock. With no help from Woodcock, we can deduce this devilish doublecut has an eerie lineage descending from (or influenced by) an early 2000s Gibson Tony Iommi SG that was possibly grabbed during the first full production run of signature models for the other Sabbath’s riff lord. This cherry cruiser rides in standard tuning, and all Slayer’s beefeaters take Ernie Ball 2223 Super Slinkys (.009–.042) for optimal cheese shredding.
From Parts Unknown
This blackheart has some DNA particles from the Iommisphere, but has been updated and intensified with a set of active EMGs that char MacCheeze’s sound to a well-done crisp. This is Slayer’s main C# guitar.
The Wham of That Burger Man
Slayer decided to do some covers on this run (Kiss and Motorhead), and he needed something unusual for those special songs. So, MacCheeze tricked his tech Bill to borrow the hammer of the gods of ground chuck—his Gibson Custom Shop ’64 Lonnie Mack Flying V. The whammy bar that was Mack’s signature addition to his Vs has been removed for use as a spatula.
After several tours supported by a Soldano Avenger—a 50W head featuring the heralded SLO-100 circuit—MacCheeze is plugging into this Marshall 1987X 50W plexi reissue, because the Avenger was burnt to a crisp during rehearsals. The modern plexi hits a custom 2x12 cab and a Fender 4x12 that was a cabinet for a solid-state M-80, but appears to have been customized by a stripe-shirted burger bandit who later sold it to MacCheeze.
Woodcock—not knowing how to make a Marshall melt like a Soldano or even a Laney LA100 BL—uses this JHS Little Black Amp Box to attenuate the plexi so it can sizzle like a SLO-100.
Slayer MacCheeze’s Pedalboard
The Soldano Avenger required no pedals (other than the Vox 847A Wah). However, Woodcock scrambled to build this board for big Mac. The burger man has a tray of greasy tone treats including a TC Electronic Spark Mini Booster, Ernie Ball Ambient Delay, Dunlop FFM2 Germanium Fuzz Face Mini, and an Ibanez TS9 Tube Screamer. Wireless and tuning duties are covered by the Shure GLXD16 Guitar Pedal Wireless System, allowing MacCheeze to shred here, there, and everywhere.
Taste Bud Cashes In on Turkey Day
Like his guitar-playing weirdo brethren, Grimalice (an overgrown and questionable taste bud) refused to talk to PG, but we found Ampeg-hoodie-wearing grifter Jonathan Hischke nearby and convinced him to cover peculiar purple’s setup. Shady character Hischke believes Grimalice scored this unique M-style bass during a Thanksgiving Day sale at Sweetwater. It’s completely stock except for the fretboard being painted barn-red, leaving the playing surface tacky as tar. Don’t let Grimalice’s lackadaisical demeanor fool you. He likes a good tussle when tangoing with his instruments.
Did Somebody Say M?
It’d be hard for any human or alien to miss these golden arches from this solar system or beyond.
Never Say Fry
If Grimalice was from this universe, you could understand why he’d have a 4-string modeled after a ’70s custom piece used by Geezer Butler for Black Sabbath’s Top of the Pops performance of “Never Say Die.” But he’s not lord of this world nor from it, so we must assume this stripped stallion that has more definition than a Merriam-Webster Dictionary gets worked for the lower-tuned jams.
Grimalice has never met an animal he wouldn’t grill, fry, or sauté, and a bat is no exception. So flying vermin decorate his fingers’ dancefloor.
The large, lavender governor of gustation plugs his doom brooms into a Fender Bassman 100T bruiser that feeds an Acoustic B410C that seems to have come from the same sandwich-stealing gear hoarder that sold Slayer his M-80 4x12.
Putting all the toppings on his beefy bottom-end are these to-go boxes that include a DigiTech FreqOut, an Electro-Harmonix Steel Leather Bass Expander, a Doc Lloyd Photon Death Ray compressor, a Broughton Audio Always On High Pass Filter, an Aguilar Tone Hammer preamp, an EarthQuaker Devices Park Fuzz Sound, a Behringer BEQ700 Bass Graphic Equalizer, a Mantic Effects Vitriol, and a Dunlop Geezer Butler Cry Baby Bass Wah. And like MacCheeze, Grimalice employs a Shure GLXD16 Guitar Pedal Wireless System.
The Van Halen-loving star sideman for Chris Cornell, Melissa Etheridge, and Don Henley, welcomes PG to his tone temple to see signature Suhrs, eight amps in a flash, and his core pedalboard.
Pete Thorn has constructed a dream career on being heard, not seen. He’s toured the world backing Chris Cornell, Don Henley, Melissa Etheridge, Jewel, and Japanese rock icon Tsuyoshi Nagabuchi (even performing at Mt. Fuji for over 100,000 fans on the biggest concert stage ever assembled in Japan). For a self-proclaimed “guitar nerd” (check out Pete’s 2011 album under the same name), it was a 21st century guitarist’s goal. After that, what does one do in between tours to stay busy and relevant in a modern world? You become a beloved YouTuber, of course!
His channel is a great destination for gear demos and comparisons, but Pete’s content stands out with his simple, and east-to-apply tone tips. (It’s worth noting that Pete did this very thing inside Premier Guitar for years with his “Tone Tips” column. Check it out!) The fun, diverse, informative videos Thorn has delivered have blossomed into a parallel profession with a built-in audience pushing 250k subscribers.
While PG was on the road in SoCal, Thorn graciously invited Chris Kies into his Hollywood-based recording sanctuary, where his YouTube channel takes form. The hour-long chat covers Thorn’s signature Suhr gear (guitars, amps, and humbuckers), he shows how his setup can switch between eight tube amps in a flash (only outdone by his ability to interchange cabs, mics, and speakers in a snap), and we dive deep into Pete’s primary pedalboard.
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Suhr Signature II
As you’ll soon find out, longtime luthier John Suhr and Pete Thorn go together like peanut butter and jelly, or, in this case, alder and maple. Suhr and Thorn have collaborated on several pieces of signature gear, and the above Pete Thorn Standard HSS is their latest. The S-style is built with a 2-piece alder body, roasted maple neck with a “Pete Thorn ’60s soft-V profile (a digitized copy of one of Thorn’s 2008 S-style Suhrs), ebony fretboard, Wilkinson WVS130 bridge, and Suhr pickups (V63 single-coils with a Thornbucker II in the bridge). Thorn is always trying the newest string offerings from Ernie Ball, and he’s currently using Primo Slinkys that are gauged .0095, .012, .016, .024, .034, and .044.
For His Spiritual Guitar Godfather
“I’ve talking a lot about Eddie Van Halen in this Rundown because he’s my spiritual guitar godfather. I’m a Van Halen nut and this guitar is something I had to have,” admits Thorn. After realizing that much of Eddie’s mind-blowing guitar work for Van Halen’s first albums were done on a 1976 Ibanez Destroyer, Thorn was on the prowl for his own. He recently acquired this “lawsuit-era” ’76 Destroyer in a Huntington Beach parking lot after securing the purchase online. The surprise of the score was that the pickups are early TV Jones P.A.F. humbuckers, because the owner that sold it to Pete actually bought it from the company’s founder Tom Jones. Pete’s thoughts: “Whatever’s going on in the pickups, they sound fantastic!”
Here’s Suhr’s first Pete Thorn Standard signature model, with quite a different recipe than the HSS. This one has a chambered mahogany body with a maple top, mahogany neck with an “even slim-C profile,” an Indian rosewood fretboard, and a pair of Pete’s Suhr humbuckers—a Thornbucker+ in the bridge and a Thornbucker in the neck. Like its successor, this one also has jumbo stainless-steel frets, Suhr locking tuners, a Wilkinson WVS130 bridge, and a Graph Tech TUSQ nut.
Sweet as Cherry Pie
This cherry Gibson ES-335 looks new or neatly relic’d, but it’s from 1963. It fell into Pete’s lap nearly 20 years ago and wasn’t an astronomical price because it had a broken headstock (and has since garnered another wound by Thorn) and one of the previous owners went at the bridge pickup cavity with a chisel trying to get at the electronics. The sweet sauce that makes this baby sing is its ’60s, low-wound P.A.F.s—original in the neck and early patent numbered in the bridge—that sound like honey tastes.
A Crusher for Chris Cornell
This meaty, hulking 2000 Gibson Les Paul Custom toured with Pete when he backed up Chris Cornell. It would see the stage for Soundgarden smashers like “Spoonman” and “Outshined.” This guitar took a lot of abuse while onstage with Thorn, as he’d often end the night ripping off the strings one by one and Cornell would slam his microphone into the pickups. During these collisions, nothing ever broke (except the strings). However, one slow-motion fall off a guitar stand onto carpet caused this axe to need headstock surgery. He dropped in a set of Thornbuckers and swapped out the gold hardware for chrome.
Not a Bad Day
During a Chris Cornell tour stop in Nashville, Thorn ventured into Gruhn Guitars to find a pre-CBS Fender Stratocaster. He walked out with this sunburst ’64. That night, he got to play it alongside Peter Frampton, starting a longtime friendship. “There’s just so many great things I remember about that day. You know, these times in your life where you’re going to have bad days, this wasn’t going to be one of them. This was a good day [laughs]. This guitar just gives me great memories.”
Thorn’s collection wouldn’t be complete without this EVH Striped Series Frankenstein named “Frankie.” It’s got the paint job, the exposed electronics, and the Floyd Rose. The rest is up to Pete. “How can you not have fun with a guitar like this? I’ve seen Paul Gilbert with one—and he’s a diehard Ibanez guy. I’ve seen Andy Wood with one—and he’s a longtime Suhr artist. We all have signatures, but we had to have one of these Frankensteins to shred on. We all bow down to the church of Eddie,” confesses Thorn.
For a dude whose main business is making videos and playing riffs, you need to maximize not only space, but inspiration. Before you is Pete Thorn’s twin tower of tone that can cover any amp sound he needs. Starting in the top left and working our way down, we have a 1972 Marshall JMP 1986 model pumping 50W, a handful of Synergy Amps modules (Synergy IICP, Engl Powerball, Soldano SLO, Vai Signature preamp, Engl Savage, Friedman BE-BB, Bogner Ecstasy, Bogner Uberschall, and a Fryette Pitbull), a Soldano SLO-100, a Jim Kelley Reverb, and a Suhr SL68. The right side is home to a Universal Audio OX Amp Top Box, a Suhr Hedgehog 50, a Top Hat Amplification Emplexador, a Suhr Pete Thorn PT100, and a Komet Concorde. Possibly the most impressive part of this whole structure is the Ampete Engineering 88S-Studio Amp and Cabinet Switcher that allows Thorn to switch between all these amps with a smash of a button.
Upside Down Cabinet Cake
The Ampete 88S runs all those amps into a late-’70s Marshall 4x12 loaded with Celestion Black Back G12M 25W speakers and mic’d with a Shure SM57 and an Audio-Technica AT4050.
Pete Thorn’s Pedalboard
For a pedal-loving session-booked YouTuber-guitarist, you gotta believe Thorn is stuffed to the gills with stompboxes. What’s above is the board he relies on for most demos and videos while performing in his Hollywood hideaway. Top left, he has a Source Audio ZIO, MXR Echoplex, Suhr Riot, Maxon Apex 808, J Rockett Archer, Ryra Tri-Pi Muff, a Strymon Mobius, and a DryBell Unit67. Elevated above them rests a Strymon TimeLine, a pair of Eventide H9s, an MXR Phase 95, a Suhr Woodshed Comp, a Boss FV-500L Foot Volume Pedal, a Dunlop CBM95 Cry Baby Mini Wah, and a DigiTech FreqOut. Everything is controlled by MusicomLab EFX-LE II Audio Controller and MIDI Pedal, and a TC Electronic PolyTune 2 Noir Mini keeps his guitars emotionally and sonically stable.