Recording - July 2014 - 22

Or, if you're not very confident of your engineering skills, you
can record direct guitar at home and then bring the tracks to a
pro studio with great amps, great mics, and great engineers.
You can also reamp bass, of course, and why stop there? You
can reamp any track: vocals, horns, acoustic guitar, whatever. How
about bagpipes through a 100 Watt Marshall head with full stack?
GWAR does that. For now, though, we'll concentrate on electric guitar.
By the way, the word "reamp" comes from "re-amplification" and
was the brand name of the first device specifically designed to do
this, which we'll discuss below. Nowadays, Radial Engineering owns
the Reamp name with the blessing of inventor John Cuniberti (who still
has a cool history/applications site at reamp.com), and sells products
based on his original designs. The name's trademarked, but it has
now been associated in general use with the reamplification process.

By Michael Schulze
You might think all you have to do is plug your guitar into the 1/4" input
of your USB interface, record it, and then connect the 1/4" output of the interface to your guitar amp, but it's not that simple. The line-level output of your interface
is way louder than the output of your guitar, so you are going to have to turn the output level way down to avoid overloading the input of the amp into extreme distortion.
Not only that, but there is another problem, which is that your USB interface and your
guitar amp don't love each other in the same way that your guitar and amp do...

ver the years this magazine has featured many articles on guitar cabinet
miking (most recently in our May 2014
issue, thanks to Eleanor Goldfield). We've
suggested comparing different mics, combining mics at the front, back, and even
inside the cabinet, trying mics at different
distances, mics pointing away from the cabinet, mics submerged in a mug of beer, mics
swung vigorously in a circle above your
head for a Leslie type effect, and on and on.
The problem with trying all those options
is that your guitarist is itching to shred, and
might not want to play the same old
Yngwie Malmsteen licks over and over for
25 minutes while you decide whether fresh
or flat beer has more "sparkle". On a
slightly more serious note, I have on occasion realized too late after the session that
the guitarist got so excited during the
magic take that she played harder and
harder, and the track has ended up way
more distorted than I realized.
Reamping can help you in these situations! In reamping, you record your usual
guitar audio track, along with the direct
output from the guitar before it gets to the
amp. After the session, when the guitarist
is at home in her jammies, you can run
the recorded direct guitar signal back to
the amp, or to a different amp, or to a
bank of 27 amps. You can play your prerecorded guitar track over and over
again, trying different amps, miking techniques, and brands of beer to your
heart's content. At 4:30 AM, once you
have your golden tone (aggressively
hopped), you simply record the result to a
new track or tracks, and you're done!

RECORDING July 2014

Impedance
There is a magical love relationship interaction between an electric guitar and a guitar amplifier. To "impede" is to get in the way of something, to hinder the progression
of something, and impedance (written Z in electrical equations) is a measure of how
much a signal is hindered in getting through a circuit. For example, a length of wire
has an effectively zero impedance, current flows down it easily... but a broken wire
has an infinite impedance! Electric guitar pickups have a relatively high output impedance, which means that it is hard to draw very much signal out of a guitar pickup.
Think of a huge tank of water with a regular garden hose coming out of it. It will take a
long time for that garden hose to fill a swimming pool, because the water can only come out
so fast. In this example we would say that the swimming pool has a very low input impedance, meaning there is very little impeding the flow of water into the huge pool. The high
impedance output of the small garden hose will not be a very efficient way to fill the pool.
But what if, instead of filling a pool, we want to squirt water at our next door neighbor's kid over the fence? We can put on one of those spray nozzles that has a very
small hole at the end. That hole is much smaller even than the small diameter garden
hose, so when we screw it on, the water in the hose gets impeded, the pressure builds
up, and we are able to squirt water all the way across the yard at little Billy next door.
Look at him run! He doesn't even know where the water is coming from! The small, high
output impedance garden hose does a fine job of providing all the necessary water
pressure to the even higher impedance spray nozzle.

Figure 1. A DI allows signal to flow both to the guitar amp (which can itself be
miked) and directly to the recording chain.

http://www.reamp.com

Recording - July 2014

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