Recording - February 2015 - 48

B Y M I K E M E T L AY

Resident Audio T4 Audio Interface
Announced by Intel and Apple in 2009
as "Light Peak" and first introduced on
new Macs in 2011, the Thunderbolt interface protocol offers a whopping 10
Gb/second data transfer in both directions-essentially PCIe performance!-
over copper wire (up to 3 meters) or fiber
optic cable (up to 100 meters!), in a
daisy-chain of up to six devices. Coppercable Thunderbolt can also power
devices requiring up to 10 Watts.
Unfortunately, Thunderbolt has been slow
to gain acceptance in the music world. Its
cables are expensive and hard to make, it's
on all new Macs but few PCs, and
Thunderbolt devices cost considerably more
than their FireWire and USB 2.0 counterparts. But that price delivers amazing performance, and users have been eagerly
watching as the first Thunderbolt audio
devices make their debut.
To the small but growing list of such
products can be added the offerings of
new firm Resident Audio, whose T4 is the
first in a line of portable and relatively
affordable Thunderbolt audio devices.
Outside and in
The T4 is a 10.6 x 4.4 x 1.8 inch tabletop box, its front panel slightly up-angled
for easy access, elegantly encased in aluminum and acrylic. It offers four audio
inputs and four audio outputs plus MIDI
I/O, all over Thunderbolt, for Windows
8+ and Mac OS 10.9+.
The front panel offers four Neutrik
Combo XLR/TRS jacks for the inputs, each
with a gain knob ringed by a multicolor
green/yellow/red LED to indicate signal
strength or clipping. Each pair of inputs
(1+2, 3+4) can be switched to Instrument
or Line input, and there's globally switchable 48V phantom power. An Input Mix
knob with LED level-meter ring accompanies a large Monitor volume control knob
that's ringed by a blue power LED.
The rear panel has four 1/4" TRS audio
outputs, a 1/4" TRS stereo headphone out,
MIDI, and Thunderbolt. There is no provision for daisy-chaining another Thunderbolt
device or for an external AC power supply.
The specs are impressive: 92 dB or more
of dynamic range, equivalent input noise of
48

RECORDING February 2015

The speed of Thunderbolt in an affordable, compact interface
-124 dBu (Gain set to +60 dBu @150 ohm
termination), and total harmonic distortion
+ noise (THD+N) under 0.01% at 1 kHz
(-1 dBFS), regardless of whether the mic,
line, or instrument inputs are selected. The
preamps provide 45 dB of gain: +15 to
+60 dBu for mic signals, 0 to +45 dBu for
line-level or instrument signals.
Making it work
The T4 can be configured in two
modes: Stereo Mix or Multichannel. In
Stereo Mix mode, the Monitor knob controls the volume of Outputs 1 and 2 and
of the Phones output simultaneously. In
Multichannel mode, four channels of
audio can be routed from your DAW to
the T4, but in this mode the Monitor knob

only controls headphone level. Output
levels are controlled by the T4 Digital
Panel software that comes with the drivers. The clean, simple T4 Digital Panel
software has meters for incoming and outgoing signals, level and stereo gang (link)
controls for the outputs, and sample rate
selection up to 96 kHz.
You access Multichannel mode by plugging a cable into Output 4; for safety, this
mutes all outputs until their levels are reset
in software. Output 3 doubles as a second headphone output if desired; plugging in here also mutes Outputs 1 and 2.
Note that unlike many such controls, the
T4's Input Mix knob only controls the direct
monitored signal from the inputs, leaving
the signal coming from the computer at the
same level at all times. It must be controlled
from T4 Digital Panel or your DAW.
The T4 employs Smart Monitoring, in
which the Inst/Line switch also controls
how input signals are panned in speakers/
headphones. Since line-level inputs are
usually in stereo, setting the switch to Line
pans a pair of inputs hard left and right in

your ears. Since guitars and basses are
usually mono (sorry, Rickenbacker owners!), the Inst setting places both inputs
panned to center. This switch also controls
panning if mics are plugged in.
This is all pretty straightforward, aside
from getting used to what happens when
you plug into Outputs 3 and 4-having
your speakers go mute when you plug in a
second set of headphones is a bit disconcerting at first!
In use
The T4 has a pristine sound, uncolored
rather than "vibey". The preamps are quite
clean except at extreme gain settings;
weaker dynamic and ribbon mics might
benefit from an external preamp feeding a

Line input instead. The Instrument inputs
have 1 Megohm impedance and don't
harm guitar or bass tone. The headphone
amp is wonderfully clear and gets good
and loud. There's really nothing to complain about in terms of sound quality
(impeccable) or latency (blazing fast).
The T4 ships with a half-meter Thunderbolt
cable-quite short, but better than no cable
at all, considering their expense. My only
minor gripes are that I'd prefer dual Monitor
knobs for separate control of output vs. headphone levels, and that without a dedicated
power supply, the T4 can't use fiber optic
Thunderbolt cables for remote setup far
away from a noisy computer.
All in all, a very impressive debut.
Resident Audio has announced other
Thunderbolt boxes in larger and smaller
configurations; this is one new company
to watch!
Price: $499.99
More from: Resident Audio,
www.residentaudio.com

http://www.residentaudio.com

Recording - February 2015

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