Solo; 20 (Solo) Led; Ol (Mute) Led; Mute - Mackie 1604vlz Owner's Manual

27. Solo

This lovable switch allows you to check signals in
the phones or control room without having to assign
them to the L-R, 1-2 or 3-4 mixes. You can solo as
many channels as you like. Solo does not interrupt
any of the other channels, buses or outputs — that's
called nondestructive solo.
Using the mode [44]
switch, the 1604VLZ4's solo
system comes in two flavors:
normal (AFL) (sometimes
called SIP, or solo-in-place)
and level set (PFL) (sometimes called PFL,
or pre-fader-listen). The mode switch is described
in tender loving detail on page 21.
Level set (PFL) taps the channel signal before
the fader. If you have a channel's fader set way
below "U" (unity gain), solo won't know that
and will send a unity gain signal to the control room,
headphones, and meter display. That may result in
a startling level boost at these outputs, depending
on the position of the solo [46] level knob.
In a nutshell, soloed channels are sent to the source
[42] mix, that ultimately feeds your control room,
headphones and meter display. Whenever solo is
engaged, all source selections (main mix, 1–2, 3–4,
and tape) are defeated, to allow the soloed channel
to do just that — solo!
28. –20 (Solo) LED
An LED that does two completely
different things! Saves space, recycles
the planet, but requires some
explanation. First, the "–20" part:
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Often referred to as "signal activity,"
this LED will flicker in time with the
signal present in that channel. It's handy
for confirming that a channel is indeed
active, and may also lend a clue as to
what the signal is. For instance, a kick
drum will cause the LED to pulse in time
with the drum, and a synth pad will cause
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it to glow a bit more steadily.
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Now for the "solo" part. When a
channel's solo switch is engaged, this
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LED will glow steadily, without flickering.
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It will also be brighter than it would be
as a –20 indicator. In conjunction with
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the rude solo light [47], you can find
a rogue solo switch quickly.
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1604VLZ4

29. OL (Mute) LED

Another LED that does two completely different
things! First, the "OL" part: "OL" means overload, or
clip. You don't want that to happen. Ever. Clipping can
happen to any mixer — it's the point where the signal's
voltage tries to exceed the supply voltages that power
the circuitry. The 1604VLZ4's OL LED will come on just
before clipping, so if you see it, take immediate action:
Perform the level-setting procedure on page 5. If that
doesn't help, check for excessive use of EQ boost or
fader gain. Like the –20 LED, it will tend to flicker in
time with that channel's signal.
Now for the "mute" part. Assuming your levels are set
correctly, the OL LED will never come on as a result of
clipping. That's pretty boring. So, to liven things up, this
LED will glow steadily when that channel's mute [30]
switch is engaged.
Here is a quick reference to these LEDs:
Name Color Flickering
–20 (SOLO) green signal present
OL (MUTE) red channel clipping

30. Mute

Engaging this switch provides the same results
as turning the channel's fader all the way down:
Any channel assignment to L-R, 1-2 or 3-4 will be
interrupted. All the post aux sends will be silenced,
as will the direct out signals on channels 1 through 8,
and the OL (mute) LED will glow. The pre aux sends,
channel insert send, and solo (in level set (PFL) mode)
will continue to function during mute.
Depending on the audio content in a channel,
engaging its mute switch may cause a slight popping
sound. This is not a problem within the mixer, and it
can be avoided: Simply engage the low cut [33] switch
on each channel (unless its low frequency content is
vitally important, such as a kick drum or bass guitar).
Low cut eliminates subsonic debris, which causes the
pop, and its effect is usually transparent.
Glowing
channel soloed
channel muted