chooSinG BeTween inTernAL And
exTernAL MicroPhone PreAMPS BY MITCH GALLAGHER
In my June 2012 column, “Delving Deeper into the Audio Interface,” we discussed
audio interfaces and how some have built-in
microphone preamps—just plug in your mic
and get recording. So why would you want to
have one or more separate mic preamps?
First of all, most audio interfaces have
a limited number of mic preamp inputs.
Interfaces with two mic preamp inputs
are common, some offer four, and some
have as many as eight. But if you’re trying to record a full band, that may not be
enough. Fortunately, many audio interfaces
offer line-level inputs along with their
built-in mic preamps. By using these line-level inputs to route signals from external
preamps into the interface, you can run
more mics simultaneously.
The second reason to use external mic
preamps is for the tonal colorations they
can provide. In most cases, the microphone
preamps that are built into audio interfaces
are designed to be clean and transparent.
But if you want a different tonal coloration,
external mic preamps can help. Some are
designed for clean and transparent operation, while others are designed to provide a
specific “color” to the signals they process.
Some offer thick mids, others offer warm
top end, and so on.
In the “clean” category, you’ll find
preamps from Grace Designs, Millennia
Media, GML, and others. “Colored” preamps include Chandler Limited, Universal
Audio, and A Designs. “Classic” mic pres
include those designed by the legendary
Rupert Neve, who has made preamps for
Neve, Focusrite, Amek, and his current
company, Rupert Neve Designs. You can
also find Neve preamp clones, such as
those from Great River, Vintech, and Brent
Averill. Many engineers love API preamps
for drums and electric guitar because of
their thick, punchy midrange response.
In my opinion, the contribution a preamp
makes to a recorded sound is often subtle
compared to the contribution made by the
microphone and mic placement. And certainly, getting the sound right at the source before
it ever goes into a mic makes the biggest contribution to the final sound. My advice is to
go for the best preamp you can get with your
resources. These days, even an inexpensive
preamp can give you great sound quality.
1. Even a super-inexpensive mic preamp like the $39 Behringer Tube Ultragain MIC100 can provide useful coloration in the studio. 2. A channel strip—like the Joemeek threeQ—offers a one-stop recording solution that connects directly to your DAW.
3. The PreSonus DigiMax D8 provides eight mic preamps that can be fed digitally into your DAW, instantly expanding the number of tracks you can record at once.
External microphone preamps can provide
features beyond boosting mic-level signals
into line-level signals. Some offer built-in
analog-to-digital converters so you can route
your microphone into the digital inputs on
your audio interface. Some preamps include
built-in equalizers so you can adjust the tone
of your signals as they pass through the box.
And some have built-in compressors for controlling dynamics as you record signals. Some
even go further with built-in de-essers, gating,
and other processing. Such preamps are usually referred to as “channel strips,” because they
resemble a channel from a full-featured mixer.
Whether these additional features are worth
having depends on how you like to work.
There are basically two camps of recording engineers. One camp likes to commit
to a sound as they are recording. They’re
happy to use EQ and compression as they
are tracking to fine-tune the signal on the
way into the recorder. Someone in this
camp would find built-in processing in a
microphone preamp to be very useful.
The other camp likes to track “dry,” with
no EQ, compression, or other processing.
The idea is to capture a robust, unaltered
signal that can be processed during mix-
down to adjust the tone or dynamics as
required. The advantage to this approach
is that you hear each signal in context of
the overall mix and are free to do what is
necessary without having to work around
EQ or compression that was applied during
recording. Someone in this camp would
prefer to have their microphone preamps
unadorned with additional features.
Mi Tch GALLAGher’S latest book is
Guitar Tone: Pursuing the Ultimate Guitar
Sound. He is the former Editor in Chief of
EQ magazine. In addition to being a writer,
he is a freelance recording engineer/pro-ducer/mastering engineer, teaches music
business and audio recording at Indiana
University/Purdue University, and is Sweetwater’s Editorial