Marshall amp-in-a-box pedals are all the rage these days, with nearly every builder of fine effects pedals having at least one in their lineup, and several having more than one. What an embarrassment of riches for the tone seeker, no? Obviously the mid-heavy Marshall crunch is a crucial and immediately recognizable sound in the panoply of iconic rock guitar tones, but owning a proper, classic Marshall amp, such as a Plexi or a JMP, is not always practical or desirable. They're typically quite loud, often unreasonably so for players that need to keep the volume modest, and neither are they terribly affordable. Yet many players would still like to have the Marshall sound as part of their palette of tones, even if they can't, or don't want to buy a Marshall amp to get it. This is precisely why the amp-in-a-box pedal was invented. The better of these pedals really can make just about any decent guitar amp take on the distinctive voice of a cranked, EL34-powered stack of British crunch. So with that in mind, here are a few of our favorite tiny boxes of Marshall tone:
Marshall Guv'nor
The first Marshall-in-a-box was the Guv'nor, produced by none other than Marshall itself. Originally released in late 1988 and produced through 1991, the Guv'nor captured that classic Marshall tone and power tube saturation in a (kinda big and ugly) box. It featured a three-band EQ section and level and gain controls, with a character that drew favorable comparisons to Marshall's JCM800 amp. The Guv'nor took a while to catch on with players of the era, probably due to Marshall's lackadaisical approach to marketing the pedal, but it eventually developed quite the reputation once the full breadth of its powers became apparent to the guitar community at large. It was a genuine stroke of brilliance on Marshall's part. The company released other, somewhat similar pedals, and has reissued the Guv'nor in various forms over the years, but the original version remains the king. This pedal is probably more popular now than ever, and there are a number of clones and clone kits of it available from various companies. Every other Marshall-in-a-box overdrive owes a debt of gratitude to the Guv'nor.
MI Audio Crunch Box
This pedal is a gorgeous monster of Marshall-flavored destruction. I'm not afraid to say that this is my personal favorite of them all, and easily one of my top five favorite dirt boxes ever. The Crunch Box is three-knob simple, has plentiful gain and output on tap, and it will enact its bigger-than-life British tone magic on any amp you put it through, instantly transforming even the most genteel boutique blues-lawyer combo into a 'roided-out stack of rock fury. Part of its power is due to its thumping low end, which can be tamed a bit with the internal presence control, should the amp in question already be a bit dark. Its output is quite robust, making it excellent for hammering the front end of a tube amp, and its gain range is very wide, from just a touch of throaty snarl at the lower end, to way more gain than any reasonable person can use as the knob rolls past the 3 o'clock mark. MI Audio discontinued the original 3-knob version of the Crunch Box, replacing it with the somewhat more versatile and feature-laden Super Crunch Box, which sounds just as good, but is afflicted with a truly unfortunate paint job. But hey, looks ain't everything. Original and V2 Crunch Boxes are widely available on the used market.
Catalinbread Dirty Little Secret
Catalinbread's DLS is probably the most talked about Marshall-in-a-box pedal on the scene today. As an integral part of the company's Foundation Overdrive series, it's designed to be an "always-on" platform for tone, built to sound great on its own and stack well with your other dirty boxes. The latest version is a complete redesign with two internally switchable modes, Super Lead and Super Bass, and a responsive, organic sounding JFET circuit that feels and sounds like juiced power tubes. It features plenty of preamp and master volume gain, with Super Lead mode having more gain than the cleaner Super Bass mode, and it can run at 18 volts DC to achieve more headroom and clarity, particularly when stacked. The DLS's tone circuit is (according to Catalinbread) an exact replica of the tone circuits on the Marshall amps it mimics, reconfiguring itself when the user switches modes, and behaving in the same exact way as the amp does when you turn the knobs. That's pretty cool, if you ask me.
Wampler Plexi-Drive
Despite its name, the Plexi-Drive, from amp-in-a-box master Brian Wampler, doesn't so much mimic a particular Marshall amp, as it just imparts an overall Marshall character to whatever it's plugged into. The sonic profile varies depending on where the controls and bass boost switch are set, invoking anything from an 18-watt combo to a roaring Plexi stack, but no matter where one turns the knobs, the Plexi-Drive is all thick bottom end and sweet, juicy mid-range. Its bass boost switch is a rather ingenious feature that helps the pedal adapt to whatever volume level it's being used at, allowing you to add some 4x12 style chunk to the sound at bedroom volumes, or tame the bass a bit when the rig is cranked and the Fletcher-Munson Curves begin getting the better of you. Wampler's Plexi-Drive is a superb pedal that is super easy to get great tones from, and definitely a standout in the company's Heritage Series.
Xotic BB Preamp
The BB Pre is a venerable old hand in the Marshall-in-a-box game, making its mark early on and retaining a loyal following even as the market has been flooded with formidable competitors. It doesn't mimic a specific amp, but it is undeniably Marshall-voiced, with a huge range of tones that go from glistening, harmonically-rich breakup to a thick, amp-like crunch. It has a wide range of output and gain possibilities, and its active EQ section can cut or boost up to 15 decibels, letting it match beautifully to just about any rig or playing situation. Xotic's BB Preamp is a true modern classic.