Mesa Boogie Express 5:25 12" Combo Amp

Every once in a while you come across a guitar item that impresses you out of the blue, an item you perhaps weren’t looking for but simply stumbled upon, that either pushes a bunch of buttons in you or impresses you with its quality or excellence. I recently had one of these experiences and it involved all of the above. I was just frittering around in a guitar store and wanted to demo a particular piece of gear. The salesman offered to plug me into a Mesa Boogie Express 5:25 amp in the demo room. Trying to keep an open mind I agreed, and it was all downhill from there.

I'm one of those people who feels like the amplifier is a substantial part of my overall sound. Given my blend of clean and driven sounds, I suppose that's understandable. On the driven sound, I have a particular distortion sound in mind and try to accomplish it without too many pedals. Over my years of looking for gear to accomplish my sound I've always worked with my ears. My searches have led me to work with many different brands of amplifier. After forty years, I really don't show signs of settling on a single brand. I work with different types for different sounds. With that in mind, I’ll be honest with you: Mesa products haven’t always impressed me. To my ear, some of the distortion sounds from artists who used them were a little raw, overly gainy, razzy, or fizzy to me. I also saw that Mesas were considered "controversial" in the online community over the years: People either loved or hated them. Then, a while back, a friend sold me a Mesa V-Twin tube preamp pedal that turned out to be the embodiment of the above sonic impressions. It was a bit difficult to dial in because its distortion and clean modes shared the same EQ and contour controls. As a result, when I got it dialed for distortion the clean sound was unusable, and vice versa. I eventually quit using the pedal, sold it, and filed the brand away as “evaluated, well-built, but unusable for my needs.” Of course, one product does not a company define, so shame on me for falling into that mindset so easily. Then along came the amp demo mentioned above. When I plugged in to the Express and made a few tweaks, I discovered a very flexible amp that sounded bigger than its physical size and offered four distinct voices to the user, two at a time.

FIRST THE SPECS: Express 5:25 1x12” Model
25 watt*, two channel, channel switching tube amplifier
12" Celestion G12 Vintage 30 speaker
Two EL84 power tube and five 12ax7 preamp tubes
Size and weight: 17.75" x 19" x 11.25" - 45lbs

Two channels, each with two gain modes, bass, middle, treble, gain, volume, reverb, and contour controls
Clean – bright, clean, and low gain
Crunch – classic rock heaven
Blues – think Tejas low-mid gain blues at the top
Burn – modern high gain, think Mesa Boogie
Foot-switchable channel, reverb, and contour controls with included footswitch
Optional contact closure remote control of the above footswitch controls
Extensive switching options for the contour controls

Series loop
One 8 and two 4 ohm speaker outputs
"Duo-class" amp topography offering 25 watt class A/B or 5 watt class A modes
Front-panel indicator for 5 watt mode
Dyna-Watt technology - According to Mesa, this feature works like a big capacitor that continuously stores up a charge and then discharges it when called upon, in this case when the amp is pushed. This makes the amp sound louder than its wattage rating (25 watts).

Neatly laid-out and dressed circuit boards. Note chassis-mounted controls
with flying leads but PC-mounted tube sockets. Click for a larger view of the guts.

The amp is very well built and solid-feeling, with a heavier-gauge chassis than others I've seen in its class. With its toggle switches, smooth controls, nice bright jewel lamp, heavy tolex, extensive rear chassis vents, and nicely-screened, crisp graphics, it gives the impression of a serious amp, rather than a cheapo. The cabinet and hardware don't rattle at high levels and the Celestion G12 Vintage 30 speaker offers a warm, full, open sound without fizz or a feeling of tightness, whether played quietly or pushed.

There are players in this world that have the mindset, “If I can’t dial in my sound on an amp in thirty seconds, it is a bad amp.” Typically, the amps they like have a signature sound or two and allow the user to access them with quick, predictable knob settings. There are some great amps of that type, mind you. I've discovered the same attitude toward mixing consoles in the recording engineering community as well. However, sometimes flexibility begets a degree of complexity that is both justified and rewarded. It is in this vein that Mesa Boogie designs their amps, requiring some thinking and experimentation but rewarding those who invest their time with wide palette of tones. Part of the unfamiliarity some people experience is due to the topology of some of the Mesa preamps. Unlike many others, Mesa places the tone stack in the Express before the main preamp gain stages to allow you to choose which of the frequency bands will enter distortion first and thus influence the flavor of the distortion. I first experienced this on a 1965 Gibson GA-55RVT Ranger (Kalamazoo Super Reverb) and later discovered it on a Traynor YRM-1 Reverbmaster. Another factor in the Mesa tone stack is that the treble control is the first in line and acts both as a treble control and an influence on the overall gain. However, once you wrap your mind around these characteristics, setting up the preamp is fairly easy. Remembering the treble/gain connection, set the treble and the gain controls concurrently. Next, remember that as gain goes up, bass and middle should probably come down for clarity. Finally, remember that there are also things you can’t do with a pre-gain EQ, such as set the overall bass and treble of the amp sound before it goes to the power amp. To allow that, Mesa has typically offered either a graphic EQ (on the Mark series) or a “Contour” control, both post-gain, to allow you to shape the final sound of the preamp as well. Here on the Express, the Contour control assumes the sound of a graphic EQ preset curve in the shape of a “v,” allowing you to scoop the mids and/or boost the highs and lows. Its single pot allows this EQ preset to be blended in any amount from none to lots. The Contour can be switched in and out from the front panel or via the footswitch. In gained-up situations, remember that the Contour will have a more profound effect on the overall bass and treble than the EQ.

Overall – In low gain situations the amp is bright and clear with a solid bass and some glass on tap via the contour. You can get very close to the archtypical Fender glassy sound. The gained-up sound in crunch mode is Marshall-esque but not as bright or razzy unless the contour is turned way up. In reviews and on forums, this amp has been described as “cold biased.” As you gain up, the high-end smoothly rolls down. Thus it is virtually impossible to get “ice-pick” overtones when using humbuckers unless you try. Also as you gain up, the sound smoothly begins to compress. The higher the gain, the more compression and sustain. If you want gain without compression, this ain't the amp for you. The amp does require some tweaking and learning because the knob settings profoundly affect the sound. You have to wrap your head around the fact that it simply doesn’t behave like a Fender - no amount of tweaking of Bass, Middle, and Treble will give you a bright distorted sound. You achieve that with the Contour. By the way, the front panel Contour switching options allow you to use Contour on both, one, or neither of the channels as you desire, and the footswitch follows your selected logic. Most channel-switching amps don’t respond well to rolling back the guitar volume to clean up the sound, but this one does pretty well. I can dial in a driven lead sound with the guitar volume on full and then back up for a good crunch. The reverb is full and lush with a reverb time that is very long. Individual send controls for each channel allow you to dial it in to the gain level of the individual channel. The basic sounds:

Class A/B mode - Stronger, bolder
Clean – Strong and clear with a tiny bit of drive available past 2 o’clock on the gain.
Crunch - You begin with a great classic rock rhythm sound to the left of 12 o’clock on the gain. The amp compresses and the sound rounds out as you gain up. You can come very close to some of David Gilmour’s gainy lead sounds to the right of 12 o’clock. You can get more articulation as you bring up the contour.
Blues – Much like the Clean channel, you start with a sparkly clean sound to the left of 12 o’clock on the gain and move up to a Tejas blues drive on the right side.
Burn – This mode offers high gain, modern drive all the way across its gain dial.

Class A mode - quieter, brighter, and dirtier
Clean – Think Vox-y chime, never quite clean.
Crunch – Think fender tweed a la the Doobies song, "Rockin’ Down the Highway."
Blues – Chimey, bright, and dirty.
Burn – Nasty (hehehehe)

Click left pic for larger view. See note on back view in "Hints/Notes" below **

With just a little volume, the amp is cleaner than at its lowest volume settings.
The amp takes drive pedals really well. I tried a little bit of fuzz ahead of the crunch channel and actually liked the result for single-string leads.
For a clean, louder amp, put a booster in the loop.
It is a good idea to put the amp on standby before switching classes via the rear-panel switch, in order to prevent an audible pop.
For classic rock types, you can reverse the intuitive channel selections and mode selections for great tones: Use the blues/burn channel in blues more with low gain for your clean sound and the clean/crunch channel set to crunch and gained up for your lead sound. It takes a little doing to get over the inversion of the classic "red for hot and green for mild" convention, but it can be done. That's the way I work.
I found the description “biased cold” very helpful in that it brought back my memory of my old Traynor (also described as biased cold). The idea is that it is a smoother, rounder distortion than a Marshall.
** The back of the amp has been updated since the picture above was shot. The raw metal aluminum bar across the tubes has been dropped in favor of a black metal cage around the power tubes, as below. I am told that the export amps always had this and the U.S. version was just brought into line with the rest.

I’m a lover of details. Mesa caters to my interests by adding a few little details that other manufacturers either don’t offer or charge extra for: The amp owner’s manual and warranty papers arrive in a rigid plastic envelope to keep them clean and neat. In the back of the amp, Mesa has placed a fabric bag secured with Velcro closures to hold the footswitch and cable in transit. A high-quality, quilted amp cover comes with the amp. A final touch is that Mesa dealers keep glossy, color Mesa catalogs right by the amps in the store, just like in the old days. The catalogs offer lots of history and product background that fills in the details that you want to know about the company, its philosophy, and its practices. Of course, leading up to a purchase, you pour over those color catalogs and dream…

I also love the level of quality control practiced by Mesa: After the chassis is assembled, they plug it in, crank it up, and bang around on it with a hammer to see if it goes microphonic or there are marginal connections that could be ready to fail. Next they play test it. Then they "burn in" the amp for twenty-four hours on the bench. Then there is a further electronic check and they install the chassis into a cabinet. Finally the amp is play tested by another person, then inspected and packed. That's a lot of attention to detail and quality. As the amp passes each of the above quality control steps, the technicians sign a card, and that card is included with each amp.

This amp pushes a lot of buttons in me. First, it offers a lot of flexibility for studio sessions, and I don’t seem to be able to loose that mindset. It puts a bunch of sounds in one small box. It offers my basic sounds for live work with switching options that make two of those sounds available at any time. It offers me portability and is a giant killer. There’s a new generation of amps coming out with really big sounds out of small packages. Being no longer an eighteen year old, I value a lot of amp in a small package to put an end to the arm stretching exercises. I do realize that the forty-five pound weight places this right at the top of small amps, but the weight seems to me to offset by how well-built the amp is. There’s one more consideration: Mesa offers this amp in both 10” and 12” speaker versions. Weighing in at thirty-eight pounds and shedding an inch in height and width, the 10” speaker version of the 5:25 reduces the size and weight even further. As you would expect, there is a change in sound. To my ears, the 10” speaker version is more "in your face," with profound but boxy bass. Rhythm sounds and class A sounds are even more reminiscent of the old tweed amps than the 12” version. However, the 12” is version has a smoother sound that is less fizzy but has a tiny bit less bass. I took my wife, who has trained ears, with me on one shopping trip. She actually preferred the sound of the 10” version. While I ended up with the 12” version, I was truly torn between the two. For those who need more oomph, the Express is also offered in a fifty watt, dual 6L6 version (5:50 Express). The preamp options are exactly the same and this version also offers the duo-class circuitry. The speaker options in the fifty watt version are either one or two 12” speakers.

Nearly identical Express 5:50 panel. Side by side Power and Standby switch layout at right is the only change. Click for a larger view.

UPDATE: I just thought I'd follow up on my review, now that I'm three months in and have had opportunity to play it out a bit. I can say my initial impressions of the amp when I wrote the review have held up extremely well and I've very pleased with it. I've learned to "work it," like Steely Dan "Learned to work the saxophone." The sounds I am trying to get just fall out of it every time I set up at a new location. The sound reminds me more and more of the Traynor Reverbmaster I foolishly sold fifteen years ago. The 12" Celestion G12 speaker has played in nicely. Nitpicks? There's just not enough space to easily fit the foot pedal in the back with all the cables, but that's no big deal because most people will be putting it on their board. The cable connection on the foot pedal feels a little less than robust, but whoopee, these are nitpicks. Bravo to Mesa for packing all these sounds into a great small box and doing it with class.

UPDATE 2: Mesa had provided a nifty little video demo of the amp and encouraged us to embed it in websites but the Express series has been replaced by the Express+ series and the video was removed.

The U.S. trade regulation demanding an empiracle measurement of wattage (RMS or Root Mean Square method) be quoted has been superceded by a new one. What led to this was the idea that the definition of RMS wasn't quite hmmmm... precise enough so it made for less than useful or biased ratings. The geniuses who replaced the regulation did so with a standard that was essentially no standard, and that has come home to roost of late. I've noticed that manufacturers are no longer taking it upon themselves to quote any standard whatsoever. That means an amp power quote of, say, "30 watts" could be 30 watts average output at full tilt, 30 watts of peak power when the amp is a second short of self-destruction, or 30 watts output at a sound level someone has deemed sane, all dependent upon whatever point the manufacturer is trying to make. I do notice, in the case of the Mesa Boogie Express 5:25, that the 25 "watt" amp was fitted with a Celestion G12 Vintage 30 speaker, a speaker that is rated at 60 "watts". We are going to assume that Mesa doesn't want amps coming back during their generous five-year warranty period because of fried speakers. If we start at that assumption and look at the more than double wattage rating of the speaker, perhaps we can infer that the amp is rated 25 watts average power and the speaker is rated the double wattage we'd expect from a speaker rated at peak power. That's the rule of thumb we used to use, at least: "Use a speaker that is rated at slightly more than twice the wattage (peak rating) of the amp (RMS rating)." But assumptions and inferences are at best shaky ground. Since I went to the trouble of learning the meanings of peak, average, and RMS back in the '70s, they mean something to me. I miss them in daily practice.