Manley VOXBOX - MVBXA 4/2003 - Manual (Page 14)

The LOW FREQUENCY ROLL-OFF switch works on mic, line and instrument inputs. We use it to reduce
room rumble, excessive proximity effect and sometimes to achieve hotter overall levels. It reduces bass a bit
gentler and smoother than most mic pre filters. It is 6 dB per octave, rather than 18 dB per octave.
A little note about the INPUT control. This control is before any other circuitry that might distort. In
a sense, it is a variable pad. Manley mic preamps can handle very hot signals cleanly because of this. The
GAIN switch, that many mistake for a pad, sets the amount of negative feedback. We sometimes use this to
optimise noise but more often use it to control how “forward” or “aggressive” we want it to sound. There
is no typical setting for the LEVEL control with mics but you will find that with line level signals, “unity
gain” is near 12:00. You may find that guitars and basses, through the front panel 1/4” input, will require,
what seems to be a high setting.
The compressor starts off being unusual in that it is before the mic pre. The attack and release are
conventional enough that any engineer familiar with compressors will be at home and may not notice these
controls are a bit unusual. As usual, ATTACK adjusts how percussive transient sounds affect compression.
At the slowest settings, (ex)plosive consonants, pops or drums should not really “trigger” the compressor.
Faster settings allow these peaks to cause compression & makes them quieter. RELEASE is the time the
compressor takes to get back to no compression or full volume. “Slow” release makes the gain creep back
to full and “fast” release brings the gain back up as quickly as possible. This is how the VOXBOX and
most compressors operate but we added a few new twists.
Normally a compressor uses this one pair of attack and release times to provide some degree of
control. Uniquely, we used 4 pairs to get it better. One pair is the light dependent resistors own attack and
release characteristic which is the basic attack and release of the original Manley Electro-Optical Limiter.
You get this winning characteristic in the VOXBOX if you dial up FAST RELEASE & FAST ATTACK.
Try this; dial up SLOW RELEASE and SLOW ATTACK and feed it some music. This combination
is set up to look like a good engineer riding a fader (a “great” engineer would anticipate a loud note but
we couldn’t quite design that in). As you move the ATTACK to MED and FAST, notice how the compres-
sor quickly handles transients like drums but for the slower sounds has very slow release. In other words
it combines the best parts of conventional controls and “auto” settings. It sounds liquid smooth and very
transparent.
MED RELEASE with MEDIUM ATTACK is for vocals - that easy.
LA-2A = FAST ATTACK & MEDIUM FAST RELEASE
LA-3A = SLOW ATTACK & MEDIUM SLOW RELEASE
MED FAST RELEASE & MED FAST ATTACK is the most complex setting. Here is four pairs
of time constants set up to be cool for drums and bass. We wanted it to be punchy with a good amount of
thump and click. You could spend hours trying to get that from most compressors. It also works nicely on
“announcers” and “commercials”. It can be a bit “pumpy” on a music mix - but without the wimpiness
that usually goes with it.
The THRESHOLD control is designed so that as you turn clockwise more compression happens.
BYPASS simply stops the light hitting the opto’s. It can be switched in and out smoothly during music !
Unlike many compressors, this one has no “make-up gain” control. The INPUT level is before the
threshold because it is a mic preamp. It makes comparing compression (in and out) not ideal when used as
a mic pre because pure compression always reduces volume. In line input mode we gave you one way to
compare. Use the EQ INPUT toggle switch between “LINE IN” (no compress) and “PRE OUT” (com-
press). You can also hear the “color” of the Manley tube circuits this way (not easily).
How much compression to use? Well it depends on the singer and other factors including taste and
experience. Most freelance engineers record vocals using the very best mic & mic pre they can get, put it
through an optical limiter and record direct to tape - no EQ, no gate, no console. A singer with wonderful
mic technique probably won’t need much compression, if any. Singers with perfect mic technique are as
rare as virgin nightclub singers ;-) Most often you can expect needing 3 to 6 dB of compression. The idea is,
use as little as possible but the vocal should stay reasonably level and not jump out and bite you or disap-
pear into the track. As you get into deeper compression you can make the quiet phrases louder along with
louder leakage from other instruments, more headphone leakage and audible room rumble. In a very quiet
room you might get away with 10 or 15 dB. The usual idea for recording is that you need to keep the vocal
sounding natural yet level controlled. A few other common problems of over-compressing are less natural
dynamics and mic technique and faster session burn-out. Serious squashing, if needed, may be better in the
mix stage. Distortion on the other hand may be better recorded on a second track. Here the vocalist has to
interact with the distortion to get the best effect. Record one signal clean and one track from the distortion
device. This gives most options in the mix. You can switch in one for some lines, or re-distort a better way,
or not. You can put a fuzz box in the Insert Loop but we suggest post EQ & Limit.
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