Review: Mesa/Boogie Mark 5 Twenty-Five

The introduction of the Mark 5 a few years ago seemed to be the last word from Mesa/Boogie in terms of packing the company’s “greatest hits” amps into a single chassis.
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The introduction of the Mark 5 a few years ago seemed to be the last word from Mesa/Boogie in terms of packing the company’s “greatest hits” amps into a single chassis. This highly successful three-channel amplifier has paved the way for the smaller two-channel Mark 5 Twenty-Five, which has two EL84 power tubes in place of its bigger brother’s quartet of 6L6s. Weighing in at only 16.5 lbs and measuring 14" wide, this radical amp offers six style modes, along with a load of features, including independent controls for each channel, a footswitchable 5-band EQ that can be assigned to either or both channels (or bypassed completely), and a CabClone cabinet simulator that, like the stand-alone version (reviewed in the January 2015 issue of GP), has an internal amp load, speaker on/off and ground-lift switches, closed-and open-back voicings, and a headphone out.

Channel 1 has a mode switch that toggles between Clean, Fat, and Crunch settings, while channel 2 lets you select Mark II C+, Mark IV, and Xtreme modes. Other details include a tube-buffered effects loop, tube-driven spring reverb with independent channel controls, and a Multi-Watt switch on both channels that lets you independently select 10- or 25-watt operation.

Tested through a Mesa Mini Rectifier 1x12 slant cabinet—and with a variety of guitars that included a Gibson Historic ’59 Les Paul, a PRS Modern Eagle II, and a Fender American Standard Tele—the Mark 5 Twenty-Five proved its ability to deliver an impressive array of sounds. Using channel 1 on the Clean setting yields a crisp tone that’s perfect for anything you’d typically deploy a Fender Deluxe Reverb on—such as country, R&B, funk grooves, and jazz. The spacious sounding spring reverb is a perfect match here, as it’s beautifully integrated with the amp’s core tone.

The Fat setting brings on more grind and serves as a fine platform for dirtier clean sounds, the thicker response adding welcome girth to single-coil pickups. In Crunch mode, the tones get much more distorted—excellent for wailing blues and rock solos—and even at high gain settings the amp maintains its superb dynamic qualities, allowing for smooth transitions from cleaner to more over-driven tones by adjusting the guitar volume or picking harder. In this mode particularly, the Mid/Boost knob—which turns into a variable gain boost as you move the knob from 5 to 10—can be used to fatten up the tones while also boosting the gain to shred levels if desired.

Switching to channel 2 unlocks the Mark 5 Twenty-Five’s classic Mesa/Boogie side by providing an excellent replication of the famed Mark IIC+ lead channel. This feat was proven in the Mark 5’s ability to nail the high-gain magic of the IIC+, so it’s not surprising that the Mark 5 Twenty-Five also dishes out that same deliciously saturated grind. Fans of IIC+ tone may never need to venture beyond this mode—especially with the 5-band EQ at hand—but that would be to overlook the Mark IV setting, which replicates the lead channel of that other Mesa classic. It’s fatter and broader sounding than the IIC+ mode, and plays well with single-coils or in any application where you seek a rounder, smoother flavor of distortion. Again, the 5-band graphic can be a useful frequency sculpting tool for beefier sounding guitars, although I didn’t feel it was necessary when using the Les Paul and Modern Eagle II, both of which sounded very balanced though the Mark IV circuit. In Xtreme mode, the amp churns out its highest level of gain and aggression, with quick transient response, plenty of in-your-face presence, and ridiculous sustain. Lifted from the Mark 5, it’s a go-to setting for thrash metal and other, well, extreme styles.

At the end of all these amazing preamp options comes the twin EL84 output stage, which has a quick response to picking attack, and a bit slimmer vibe compared to 6L6s. You can push the volume to high levels without the tones becoming mushy sounding, and while optimal performance is via the 25-watt setting, running either or both channels in the 10-watt setting (class AB triode) definitely tames the volume for rehearsals, practice, etc., while also letting you run the output stage harder to take advantage of power tube distortion—something that EL84s seem born to do. For late night practicing, the CabClone section lets you shut off the main speaker outs and route the full amp signal though cabinet-simulator circuitry—listening to it all though headphones with open-and closed-back settings to choose from. Way cool! The CabClone also features a balanced XLR out for sending a direct signal to the P.A. or recording console, as well as a ground-lift switch to mitigate hum problems when interfacing with external gear.

The Mark 5 Twenty-Five affords the player an almost unbelievable amount of tone options in a package that is extremely easy to tote. How Mesa founder Randall Smith managed to engineer six different amplifier modes into this tiny head is nothing short of a mind blower, and the result is a unit that delivers more sounds per pound than any all-tube amplifier on the market. With its “library” of classic Boogie circuits, multitude of hip features, and elegant interface, the Mark 5 Twenty-Five represents a quantum leap in guitar amp technology and earns an Editors’ Pick Award.


Mark 5 Twenty-Five
PRICE $1,299 street


CONTROLS Channel 1: Gain, Treble, Mid/Boost, Bass, Presence, Reverb (rear panel), Master controls. Clean/Fat/Crunch switch, Multi- Watt switch (10 watts/25 watts). Channel 2: Gain, Treble, Mid/Boost, Bass, Presence, Reverb (rear panel), Master controls. Mark IIC+/Mark IV/Xtreme switch, Multi-Watt switch (10 watts/25 watts).
TUBES Six 12AX7s, two EL84s
POWER 25 watts/10 watts
EXTRAS Footswitchable, channelassignable 5-band graphic EQ with bypass switch. Tubedriven spring reverb. Tubebuffered effects loop. Built-in CabClone speaker simulator. Padded cover and 2-button footswitch included.
SPEAKERS Tested with Mesa Mini Rectifier 1x12 slant cabinet ($449 street)
WEIGHT 16.5 lbs
KUDOS Incredible tonal range. Super portable. Excellent features. CabClone cabinet simulator.