Only Mesa/Boogie would release an amp with such versatility that the manual would be bigger than the amp itself. There’s a clear trend toward building lunchbox-sized amp, and Mesa makes no attempt to hide the fact that they are late to the parade with their TransAtlantic TA-15. But unlike many of its competitors, Mesa brings more to the table than just shrinkage.

Sizing It Up
Download Example 1
HI1 Setting, 5W
Download Example 2
HI2 Setting, 5 W
Download Example 3
Top Boost Setting, 5W
Download Example 4
Tweed Setting, 5W
All samples recorded with a Gibson SG (bridge pup) and matching Mesa/Boogie 1x12" cabinet.
As its name implies, the two-channel, 12 lb. TransAtlantic is designed to deliver a variety of British and American tones via four 12AX7s and two EL84s. Front-panel controls may seem a bit skimpy compared to most Mesa amps—and players familiar with Boogies that have more rear-panel controls than most amps have altogether will be shocked to hear that there aren’t any controls on the TA-15’s back. However, close inspection of the front panel reveals a pushpull pot and multi-position toggle switch that places the TransAtlantic into the same family as its big brothers, in terms of tonal flexibility. Mesa knows fans of their amps thrive on versatile routing and, as such, would likely feel trapped by the lack of controls on most lunchbox amps. The amp does not include an effects loop or an emulated line out, so in that regard it’s more akin to fully loaded heads than some of its small peers.

From left to right, the TA-15’s control panel features two rugged input jacks—one for your guitar and one for the single-button footswitch. Scanning Channel 1’s knobs, we have Volume, Treble, Bass, and Cut/Master, the latter of which is the only push/pull knob on the amp. When pushed in, the knob functions as an inverted Presence control (the sound gets darker as you go clockwise). Pulled out, it functions as a master volume for Channel 1, allowing you to drive this “clean side” of the amp into delicious overdrive. The Treble and Bass knobs furnish a pretty wide range of EQ attenuation, however, if you’re really into midrange you may find that it’s a bit trickier to dial it in without a dedicated control. Channel 2 dispenses with the push/pull knob and gives you a straight Master knob, in addition to Gain, Treble, and Bass knobs.

The TransAtlantic also features 4- and 8-ohm speaker outs, and the exceptionally well-written manual illustrates numerous cabinet configurations. I tested the TransAtlantic with a matching 1x12" Mesa open-back cabinet. Loaded with a 90-watt Black Shadow speaker designed for Mesa by Celestion, this nifty cab easily accommodated the TransAtlantic’s wide variety of tones. The amp head also comes with a padded gig bag. Sweet!

Meet the Toggle Switches
A bank of five mini toggles separates the knobs for Channels 1 and 2. Two switches are dedicated to Channel 1, two are dedicated to Channel 2, and one toggles between channels or allows footswitching. Each channel has a toggle to select a voicing and wattage. For Channel 1, the voicing options are Normal and Top Boost. Normal yields a good, standard clean tone with lots of headroom. Top Boost provides us with our first TransAtlantic journey to the UK, home of Vox amplifiers. Much like the fine AC30, this channel is crisp and articulate, and boasts an open low end. This setting allows your fretting technique to shine by preserving every subtle, touch-sensitive nuance as you glide and slide over the strings. Top Boost also delivers that faithfully dirty crunch that may become harsh if you’re not paying attention to your EQ settings. A simple tweak of the EQ allows those singing midrange tones through. Playing with this Top Boost voicing, I found myself losing track of time under the influence of infectious pop songs from Liverpool.

Each TransAtlantic channel also has a three-position toggle to switch between 5-, 15-, and 25-watt operation. It’s not often guitarists get the chance to clearly experience the sound power tubes make when they approach their limits. Even a 35-watt amp can pummel your eardrums to the point where your ability to discern the subtle effect of power-tube drive is diminished. One way to experience the effect is to record at high volumes and listen on studio reference monitors at low volumes. But most guitarists know there’s no substitute for the direct, speaker-to-string-to-pickup cycle to make an amplifier dance.

With the amp still in Channel 1’s Top Boost voicing, I switched to the 5-watt power setting (which doesn’t require powering down or hitting standby). With the Volume at 10 o’clock and the Master/Cut knob pulled, I was able to use the Master volume to put the power tubes to work. As the Master volume goes up, the sound changes from subtle compression to limiting, and finally to a gentle overdrive at about 2 o’clock. What I’m trying and inevitably failing to describe is my favorite TransAtlantic setting: Channel 1’s Vox-inspired, low-watt, power-tube drive. It breathes, it’s responsive, it sustains, and the touch sensitivity inspires musical expression. This multi-watt design adds tons of flexibility to an already capable amplifier. A cool feature I’d like to see is multi-watt selection and voicing selection via the footswitch.