Plexi tone in a petite package.
Fine plexi-style tones at reasonable levels. Solid workmanship. Big-sounding low-wattage mode.
A bit pricy for a small circuit-board combo.
Ease of Use:
It’s been 54 years since Pete Townshend persuaded Jim Marshall to create the first 100-watt guitar amp: the Model 1959 Super Lead. And for almost as long, guitarists have sought ways to replicate the thunder of that definitive “plexi” amp without having to contend with its daunting bulk and literally deafening levels.
For many years, the 18-watt Marshall Combo was one of the few ways to experience "Marshall-ness" in the 20-watt power range. This amp and its spinoffs provide unmistakable Marshall crunch at relatively reasonable levels. But with their open-back cabinets and dual EL84 power tubes, 18-watt Marshalls don’t entirely replicate the overdrive characteristics of their bigger EL34-based cousins, or the distinctive phase cancellation of their 4x12 cabinets. More recent solutions include Marshall-mimicking hardware and software modelers and “Marshall in a box” distortion pedals.
Enter Marshall’s new SV20C Studio Vintage, specifically designed to capture the 1959 sound in a compact 20-watt combo. (The amp is also available as the head-only SV20H.) It’s approximately as powerful as an 18-watt, but it employs a pair of EL34s—the same tubes used in the big plexis. This two-tube architecture means that the SV20C is actually closer kin to dual-EL34 50-watt plexis than to 4xEL34 100-watt plexis. Likewise, the single 10" speaker doesn’t replicate the spectral intricacies of a 4x12 cab.
Still, this U.K.-made combo gets closer to the plexi sound than an 18-watt. The EL84s in an 18-watt Marshall distort at relatively low levels and generate crackling, Vox-like highs, while the EL34s used here are more mid-focused and have higher headroom. Compared to an 18-watt, the SV20C also has beefier lows, more prominent mids, and warmer/darker treble response.
The SV20C has both normal and bright channels, each with a gain control and two input jacks. As on vintage plexis, there’s no master volume, but you can summon extra gain by linking the channels with a jumper wire.
Immediately after unboxing, I applied the super-lazy “Don’t Make Me Come Over There” test. I cranked the normal channel’s gain, parked the tone knobs at noon, and plugged in a DIY dual-humbucker guitar. Then I sat across the room from the amp, seeing how much tonal variation I could summon using only finger pressure and the guitar’s pickup selector and volume/tone controls. You can hear the results in Clip 1.
No question: The SV20C captures the extreme dynamic response for which plexis are famed. You can veer from clean to crunch to “Stand back!” using only your guitar’s volume knob. At the clip’s 1:13 point, I click on a homemade germanium treble booster similar to something a Marshall player might have used back when plexis were new-fangled. Even when slamming the amp’s input like this, there’s strong note definition and remarkably little noise.
While you won’t mistake the amp’s 10" speaker for a 4x12 cab, you’d never call it wimpy. It’s a 50-watt Celestion V-Type, which aims for a retro sound despite its modern ceramic magnet. It’s got an attractively craggy upper-mid presence that emphasizes the distortion’s “tooth” and keeps tones from sounding excessively compressed. (I miked it with a fat-sounding Royer R-121 ribbon mic.) Using a single smaller-format speaker with a ceramic magnet reduces the amp’s weight to a manageable 35 pounds.
Variations on Vintage
In the remaining audio clips, I demonstrate additional amp features by routing a single reamped passage through the SV20C while twiddling the amp’s settings. In Clip 2, you hear the excerpt at both full 20-watt power and 5-watt mode. Levels aside, the two tones are nearly identical. You can definitely get fire-breathing tones at this low-power setting!
Other non-vintage features include a mono effects loop and a 1/4" direct-out jack. This DI out(Clip 3) doesn’t produce a realistic speaker sound, though you could get convincing results using software impulse responses or a hardware speaker modeler such as the Universal Audio Ox.
In Clip 4, you hear the same performance four ways: through the normal channel, then the normal channel jumpered to the bright channel, then the bright channel alone, and then the bright channel jumpered to the normal channel again, but via different jacks. Finally, Clip 5 demonstrates the tone controls. I twist them throughout their ranges while the reamped passage plays.
The amp’s cosmetics are strictly traditional, from the gold piping to the salt-and-pepper grille cloth pattern. Inside, though, Marshall employs modern circuit boards rather than the traditional turrets. It’s solid work, employing heavy-gauge wire for the off-board connections.
Marshall’s SV20C Studio Vintage aces its primary mission: capturing authentic plexi tone in a compact, relatively low-wattage combo. Weighing 35 pounds and measuring approximately 20"x18"x10", it’s a practical gigging companion, with enough output to hold its own against all but the loudest drummers. An effects loop and low-power mode are welcome modern updates. The $1.5K price tag may seem steep for a small-format circuit-board model made with standard-issue parts, yet it’s a reassuringly solid build that should provide many years of service.
Watch the First Look: