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
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.