Universal Audio 4-710d Four-Channel Tone-Blending - Manual (Page 25)

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Insider’s Secrets
The Best of Both Worlds
There’s a reason why tube preamplifiers have long been favored by audio engineers (especially in this
age of digital recording): they impart a warmth and richness that makes most sounds larger than life.
However, there is no denying that tube preamps also tend to color the incoming signal somewhat,
albeit in a way which most listeners find pleasant and desirable.
On the other hand, the recording of voice and acoustic instruments sometimes requires precise signal
handling with meticulous attention to detail, definition and accuracy. Applications such as classical or
jazz recording demand faithful transfer of performances exactly as they happen, without coloration,
processing, noise or distortion, and that is where solid-state preamplifiers shine. Plus, by capturing
the sound as it is, you can leave sound sculpting and “coloration” decisions until later, during the
mixing stage.
So the question is, which kind of preamp to use? Up until now, the only solution has been to have an
arsenal of both kinds at your disposal, but with the 4-710d, that’s no longer necessary, since it
provides both designs in one box, as well as a unique Blend control that allows the user to dial in the
precise contribution of each preamp to the overall sound. As a good starting point, we recommend that
you set the Blend control to the desired degree of tube coloration, then back it off slightly (towards the
TRANS position) to dial in the precise amount of “snap” and detail you want in your sound.
Drive Metering
Because it shares lineage with vintage guitar amplifier designs, the 4-710d’s tube preamplifier can
contribute precise amounts of even-order harmonic distortion (the kind the ear enjoys listening to) to
your signal, ranging from pleasant amounts of rasp to all-out grunge. The Drive meter function can be
a great tool in helping to decide how high to raise the Gain control because it indicates how much tube
saturation is going to be present in the output signal. It does this by monitoring the signal that is
driving the tube. If what you want is crystal clear tube tone, then the meter will be bouncing around
near the low end of its range. If what you are after is a ton of tube dirt, then drive the meter into the
red; there is nothing wrong with either extreme. Once you use the Drive function a few times, you will
develop a feel for it, and should be able to dial in the desired tube character quickly and easily.
When in Drive mode, the 4-710d meter is calibrated so that 0VU is equal to 1.2% THD on a 1KHz sine
wave. However, measured distortion levels can be misleading because they are so source and style
dependent. 2% THD on a sine wave is a fair amount of distortion and will be apparent to even the non-
musically inclined. On a vocal track, however, that same 2% THD sounds like some really nice tube
warmth. On an overdriven guitar, 2% is barely even audible. The most important thing to remember
when using the Drive function is that there is no “wrong” meter reading, only wrong tones for a
particular track. So use the meter as guide, not as a pass/fail test. Do what feels and sounds right,
and don’t be afraid to push it.
Vocals, Vocals, Vocals
Just as certain microphones work best with certain vocalists, so too do certain mic preamps. The
presence of not just one, but two completely discrete preamps in the 4-710d mean that it will work
wonders with just about any microphone... and with just about any vocalist.
The crisp precision of a condenser microphone, for example, can be matched perfectly by the uncolored
accuracy of the 4-710d’s transimpedance solid-state preamp... or you can instead opt to use the tube
side to “warm up” the tone. Better yet, use the Blend control to dial in exactly the right amount of both
preamps to match both the microphone’s frequency characteristics and the timbral quality of the
vocalist. And if you’re using the already warm sound of a tube microphone for vocals, try