We’ve all watched the guitar amp deconstruct before our eyes, as pedals, preamps, and power amps all shrink – and migrate to the pedalboard. The builders at ValveTrain know this, and have developed a way to deploy your favorite stompboxes and modeling gear, yet retain that essential tube tone. Enter the PowerTrain Studio 20 and Studio 50 “powered monitors.”

As good as modeling gear is these days, you still can’t accurately reproduce the sound of a tube amp pumping air through a speaker. There are no real features on the PowerTrain other than turning it on and letting its tubes warm up; your only job is to plug in a modeling amp or most any multi-effects unit. From there, the monitor sends signal through an analog path starting with a 12AX7 preamp tube, two matched 6V6 power tubes, solid-state rectifier, and an Eminence Copperhead 10″ speaker.

Tested with a multi-effects modeler and a Boss Katana amp, the PowerTrain Studio 20 moved a lot of air as the digital preamp and effects became dipped in pure analog goodness, revealing an immediate sonic improvement that was stark. Furthermore, the PowerTrain produces a very loud 20 watts, enough to play a small gig or jam at home. One can assume the 1×12-loaded Studio 50 would shake, rattle, and roll your walls even more.

Even the most ardent digital defender will have to admit the Studio 20 is one sweet-sounding monitor. And while it’s as pricey as many full-on, hand-wired tube amps, if you want the special sauce to make your modeler sound better, it’s a great place to start.

This article originally appeared in VG’s February 2022 issue. All copyrights are by the author and Vintage Guitar magazine. Unauthorized replication or use is strictly prohibited.