Line Inputs; Trim; Insert; Direct Out - Mackie 1604-VLZ PRO Owner's Manual

LINE INPUTS

These 1 / " jacks share circuitry (but not
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phantom power) with the mic preamps. You
can use these inputs for virtually any signal
you'll come across, from instrument levels as
low as –50dB to operating levels of –10dBV to
+4dBu, as there is 60dB of gain available via
the TRIM knob
. Always be sure to perform
the Level-Setting Procedure .
To learn how signals are routed from these
inputs: . To connect balanced lines to these
1
inputs, use a / " tip-ring-sleeve (TRS) plug,
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the type found on some stereo headphones:
RING
TIP
Tip = positive (+ or hot)
Ring = negative (– or cold)
Sleeve = shield or ground
To connect unbalanced lines to these in-
puts, use a 1 / " mono (TS) phone plug or
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standard instrument cable:
SLEEVE
TIP
Tip = signal (+)
Sleeve = ground

TRIM

Yes it's true, these controls are not located
in the patchbay section at all. They're found
along the top row of knobs in the channel strip
section. But their purpose is so closely linked
with the MIC and LINE input jacks that we
couldn't bear to separate them. Here's why:
Every time you plug something into a MIC or
LINE input jack, you should perform the Level-
Setting Procedure , and that procedure is
basically "how to use the TRIM knob."
TRIM adjusts the input sensitivity of the
MIC and LINE inputs. This allows signals from
the outside world to be adjusted to optimal
internal operating levels.
Through the XLR jack (MIC), there will be
0dB of gain with the knob fully down, ramping
to 60dB of gain fully up.
Through the 1 / " input (LINE), there is 15dB
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of attenuation fully down and 45dB of gain fully
up, with a "U" (unity gain) mark at 10:00.
when you are inserting a signal that is very hot,
or you want to add a lot of EQ gain, or both.
Without this "virtual pad," a scenario like that
might lead to channel clipping.
effects processors such as compressors, equaliz-
ers, de-essers, or filters . The INSERT point is
after the TRIM control, but before the channel's
EQ, LOW CUT, fader and MUTE controls. Insert
cables must be wired thusly:
SLEEVE SLEEVE RING TIP
tip
This plug connects to one of the
RING
mixer's Channel Insert jacks.
TIP
Tip = send (output to effects device)
SLEEVE
Ring = return (input from effects device)
Sleeve = common ground
DIRECT OUT jacks
be used as channel direct outputs; post-TRIM,
pre-LOW CUT, and pre-EQ. Here's three ways
you can use the INSERT jacks:
SLEEVE TIP
TIP
SLEEVE
(TIP = SEND to effect, RING = RETURN from effect.)
deliver the signal from the very end of the
channel path; post-TRIM, post-EQ, post-LOW
CUT, post-fader and post-MUTE. They are the
key player in "split monitoring," making the
1604-VLZ PRO perfect for an 8-track studio. To
wire your own cables:
This 15dB of attenuation can be very handy

INSERT

These 1 / " jacks are for connecting serial
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ring
(TRS plug)
sleeve
Even though channels 1–8 already have
, INSERT jacks can also
MONO PLUG
Direct out with no signal interruption to master.
Insert only to first "click."
MONO PLUG
Direct out with signal interruption to master.
Insert all the way in to the second "click."
STEREO
PLUG
For use as an effects loop.

DIRECT OUT

Found only on channels 1–8, these
.
SEND to processor
"tip"
"ring"
RETURN from processor
Channel Insert jack
Channel Insert jack
Channel Insert jack
1
/ " jacks
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