MIXER ANATOMY: CHAPTER 2

Inputs, Outputs, and Related Controls

Mackie E-Z Interfacing the mixer. So, while there’s a wide adjustment range
for both mic and line inputs, the mic inputs have
Concerned about levels, balancing, impedance, higher gain.
polarity, or other interface goblins? Don’t be. On
your Mackie mixer, you can connect almost anything Don’t forget the Level-Setting Proce-
almost anywhere, with nary a care. Here’s why: dure at the beginning of this book. Mic
and line inputs are happiest when run-
• Every main input and output is balanced. ning at the optimum levels. That procedure will get
you there.
• Every 1/4" input and output jack also accepts
unbalanced connections. Check the Tips section and Glossary for more infor-
mation about terms we’ll be using here like operating
• Every input is designed to accept virtually any
level, impedance, balanced, unbalanced, XLR, and
output impedance.
TRS. Also study the mixer block diagrams, as each
• The main left and right mix outputs can de- one is worth a thousand words or more.
liver +28 dBu into a 600 ohm load (that’s hot!)
• All the other outputs can deliver +22 dBu into
Mic Inputs
a 600 ohm load (that’s plenty). Mackie mixers include phantom-powered, bal-
anced XLR microphone inputs just like the big studio
• All the outputs are in phase with the inputs.
mega-consoles, and for exactly the same reason:
All Mackie mixers have both microphone and line- A fully balanced circuit is excellent at rejecting
level inputs. Some channels have both, some chan- hum and noise, and phantom powering means that
nels have only line-level inputs. Consult your mixer’s condenser mics can be used without external power
quick start guide (or just look at the connector supplies or batteries.
panel) for the exact arrangement. Below is the rear
You can plug in almost any kind of mic that has a
panel of the 1604-VLZ PRO.
standard male XLR-type connector without fear of
overloading the preamp. Professional ribbon, dy-
Mic? Line? – What’s The Difference? namic, and condenser mics all sound great through
Microphones produce a relatively low these inputs.
voltage, generally in the range of 1 to 250
millivolts, depending on the sensitivity of XLR Input Connectors – Mic wiring
the mic, and how loud the sound is. Voltages in the Nearly all professional mics are designed to con-
0.15 to 3 volt range are considered to be line-level. nect to a low impedance input, and employ balanced
These aren’t rules or standards, just ways of talking wiring terminating in an XLR-style plug. You’ll find an
about two widely different operating voltage ranges, illustration and wiring diagram in the Tips section,
both of which are common in audio. chapter 9. We use the wiring convention:
A microphone typically requires 20 to 60 dB of gain Pin 1 = shield
in order to bring its signal up to the mixer’s operat- Pin 2 = positive (+ or hot)
ing level. A line-level signal requires little if any gain, Pin 3 = negative (- or cold)
and may need to be brought down in level to match

120 VAC 50/60 Hz 20W POWER PHANTOM MAIN OUT MAIN INSERT TAPE TAPE C-R OUT SUB OUT AUX RETURN AUX SEND DIRECT OUT
1A/250V SLO-BLO ON ON BAL/UNBAL (TIP SEND INPUT OUTPUT BAL/UNBAL BAL/UNBAL BAL/UNBAL BAL/UNBAL BAL/UNBAL
RING RETURN)
L L L 3 1 4 3 2 1 5 3 1 7 5 3 1

L L
L L L
(MONO) (MONO) (MONO)
MONO
R R R 4 2 6 4 2 8 6 4 2
R R R
CAUTION: R R
TO REDUCE THE RISK OF
FIRE REPLACE WITH SAME
TYPE FUSE AND RATING OO +6
UTILISE
UTILISE UN
UN FUSIBLE
FUSIBLE DE
DE RECHANGE
RECHANGE DE
DE MÊME
MÊMETYPE.
TYPE.DEBRANCHER
DEBRANCHERAVANT
AVANT DE
DE REMPLACER
REMPLACER LE
LE FUSIBLE
FUSIBLE
INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT INSERT

LINE 16 LINE 15 LINE 14 LINE 13 LINE 12 LINE 11 LINE 10 LINE 9 LINE 8 LINE 7 LINE 6 LINE 5 LINE 4 LINE 3 LINE 2 LINE 1
BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL
UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN- UN-
BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL BAL

MIC 16 MIC 15 MIC 14 MIC 13 MIC 12 MIC 11 MIC 10 MIC 9 MIC 8 MIC 7 MIC 6 MIC 5 MIC 4 MIC 3 MIC 2 MIC 1
MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR MIC PR
XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E XD R E

XDRTM EXTENDED DYNAMIC RANGE MIC PREAMPLIFIERS ARE PROPRIETARY TO MACKIE DESIGNS, INC.
CONCEIVED, DESIGNED, AND MANUFACTURED BY MACKIE DESIGNS INC • WOODINVILLE • WA • USA • MADE IN USA • FABRIQUE AU USA • COPYRIGHT ©1998 • THE FOLLOWING ARE TRADEMARKS OR REGISTERED TRADEMARKS OF MACKIE DESIGN INC.: "MACKIE", "VLZ", "XDR", AND THE "RUNNING MAN" FIGURE • US PATENT NUMBER 29/049,129

Compact Mixer Reference Guide 17

MIXER ANATOMY: CHAPTER 2
Even though microphones produce alter- Barenekked Preamps!
nating current (AC), they have a definite
polarity orientation. Be sure that you don’t People have thought highly of Mackie mic pre-
reverse the wires between pins 2 and 3. amps for a long time, so when it was time to put the
engineers to work on some new designs, they brought
Did you pick up a cool retro mic at a yard sale that us the Onyx series, which includes the 800R. This an-
has a 1/4" phone plug instead of an XLR? Chances are swers a popular customer request for a rack-mounted
it’s a high impedance mic and it will require a match- unit with eight mic preamps, but no other mixer
ing transformer in order to sound its best with your features. The 800R has a few neat tricks up its sleeve
mixer. Plug-in transformers available from several which we’ll discuss later, but we wanted to mention it
sources will not only match the impedance and signal in this discussion about microphone preamps.
level, but will adapt the plug too.
Dynamic and ribbon mics don’t like to
Phantom Power see DC voltage applied to their sensitive
insides. Normally it won’t be, but a shorted
Most condenser mics require phantom power, a or miswired mic cable can cause the full voltage to
system whereby the mixer supplies a DC voltage to appear across the sensitive microphone element. Be
the mic’s electronics through the same wires that sure that your cables are in good condition before ap-
carry audio. plying phantom power.
The phantom power on all Mackie mixers (except Also, unless you know for certain that it is safe to
the Onyx series) is globally controlled by the PHAN- do so, never plug single-ended (unbalanced) micro-
TOM switch on the rear panel (one switch for each phones, instruments, or electronic devices into the
group of 8 mics on the 8-Bus). A PHAMTOM LED on MIC input jacks if the phantom power is on.
the front panel will remind you that phantom power
is turned on. The Onyx mixers have a 48V switch and Practice safe phantom powering! Plug in
LED indicator on each channel for selective control of your mics with phantom power switched
phantom power. off! The XDR preamps used in many Mackie
mixers have extra protection against damage from
“Phantom” owes its name to the ability to disappear “hot plugging,” but your mics don’t. Get into the habit
when it’s not needed, like when connecting dynamic of plugging mic cables in with the phantom power off,
mics (Shure® SM57/SM58, for instance) that don’t then turning it on.
require external power.
The most common phantom power supply is 48 Line Inputs
volts. All Mackie mixers have a 48 volt phantom
Line inputs on Mackie mixers are on 1/4" TRS (tip-
supply with the exception of the PPM series, which
ring-sleeve - the parts of the mating plug) jacks. All
provide 15 volts. Some microphones will operate just
Mackie line inputs are balanced and present a mod-
fine on lower voltages while others require the full 48
erately high impedance load, around 10 kΩ, depend-
volts. Check your mics’ specs.
ing on the model and the particular input. As we’ve
Here’s what the phantom powering circuit looks seen from our block diagram tour, LINE IN jacks on
like: channels with both line and mic inputs share circuitry
(but not phantom power) with the mic preamps.
2
1 You can use these inputs for virtually any line-level
0V signal. With proper adjustment of the TRIM control,
3 they’ll accept signals over a range of approximately
48 V 48 V –45 to +16 dBu.
Some Mackie mixers are equipped with stereo line
There’s 48 volts between pins 1 and 2 and between inputs. These have two line-level input jacks which
pins 1 and 3. Since pins 2 and 3 are both at the same share a common set of controls. To learn how signals
DC potential, the voltage difference between them is are routed from these inputs, consult the block dia-
zero. That’s why an unpowered mic doesn’t “see” the gram or quick start guide for your mixer, or check the
voltage. Controls section of this manual.

18 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2
Always be sure to perform the Level-Setting Pro- sound, but the guitar will lose punch and treble. The
cedure when connecting to LINE inputs that have proper way to connect an instrument pickup directly
TRIM controls, and check the level and adjust it to a Mackie mixer is to use a Direct Box (or DI =Di-
externally on the stereo inputs without TRIMs. rect Injection) between the guitar and a MIC input.
To connect balanced sources to the line-level Hi-Z Guitar Inputs
inputs, use a 1/4" tip-ring-sleeve (TRS) plug, the type
found on some stereo headphones: 1
After all that, we decided that it
ON
YX MIC PR
E
would be a good idea to build a direct in-
RING SLEEVE SLEEVE RING TIP
strument input into some of our mixers.
TIP On channels 1 and 2 of the Onyx series
RING mixers and 800R preamp, the MIC/HI-Z
HI-Z
TIP 1
MIC
switch switches the channel input from
HI-Z
SLEEVE the XLR mic connector to the 1/4" input
jack. This jack provides a high imped-
To connect unbalanced line-level sources, use 48V
ance input suitable for directly connect-
a cable with 1/4" mono (TS) plugs. In music store 20
U
30
40 ing an instrument pickup, saving you
lingo, that’s an “instrument cable” or “quarter inch U
-20dB
60
+40dB the cost and fuss of using a DI. We’re not
patch cord.” When a TS plug is inserted into a TRS GAIN
stuffy – you can plug your bass in here,
jack, the Ring (low signal) and Sleeve (ground) get too.
connected together.
The Hi-Z jack also serves as a line input jack (it
See the Mixer Tips section for more information on has the same gain as the line inputs on the other
balanced and unbalanced connections. channels). When using line inputs with channels 1
and 2, don’t forget to push the “Guitar” button.
The TRIM Control
TRIM 1 The TRIM control adjusts the Tape Returns (8-Bus Only)
-10dGBV
U MI
C AIN input sensitivity of the MIC or LINE The TAPE RETURN jacks on the rear panel of the
IN jack, to match the input signal 8-Bus console are for connecting the outputs of a
to the operating range of the mixer. multitrack recorder.
0 60
+15dB -45dB On all Mackie mixing consoles with
the exception of the PPM series, 15 13 11 9

the TRIM control is located at the top of the channel OPERATING

LEVEL CH. 9-16
strip. That makes it easy to find, since TRIM is the IN –10dBV
OUT +4dBu

first control the signal encounters on its way through 16 14 12 10

the console. The PPM series has an Input Level Set +4 / –10 BALANCED / UNBALANCED

TAPE RETURNS 9-16

control and LED indicator above each channel’s

VOLUME control. These are balanced 1/4" TRS jacks which will
also accommodate unbalanced connections. They’re
Whenever you connect a new input, or the input grouped in sets of eight, with each group having an
source changes (you move the mic from the dulcimer OPERATING LEVEL switch to properly match the
to the kick drum), you should perform the Level-Set- gain of these inputs to pro (+4 dBu) or semi-pro
ting Procedure. That procedure is “how to use the (-10 dBV) recorders.
TRIM control.”
TAPE RETURN jacks can be routed to either the
Connecting Electronic Instruments channel (for mixing) or Mix-B (during tracking).
Their fate is determined by the FLIP and MIX-B
Synthesizers, guitar processors, other SOURCE switches.
electronic instruments, and computer
sound cards work fine when connected Tape Inputs
to the LINE inputs. The pickups on electric guitars
and basses, even though the plug fits, are a different These unbalanced RCA TAPE INPUT jacks are
animal, however. Pickups require a higher input im- designed to work with semi-pro as well as pro record-
pedance than the Mackie LINE IN provides. Plugging ers. The provide an unbalanced input at 0 dBu. Con-
a guitar into a LINE IN jack will probably make some nect your 2-track tape recorder’s outputs here, using
standard RCA cables.

Compact Mixer Reference Guide 19

MIXER ANATOMY: CHAPTER 2
In recording applications, the TAPE INPUT jacks bus outputs to slate the tape. (“Purple Tears, take
provide a convenient way to play back your mixes seventeen.”)
through the Control Room monitors. You’ll be able
The Onyx series mixers let you have it both ways.
to listen to a mix, then rewind and try another pass
There’s a built-in talkback mic as well as a connector
without repatching or disturbing the mixer levels. In
for an external talkback mic. It has 48 V phantom
sound reinforcement applications, you can use these
power (always applied), so you can use a condenser
jacks to feed intermission music from a tape or CD
mic if you wish. Remember, though, that it’s not a
player without tying up a mixer channel.
good idea to “hot plug” a mic to a connector that has
If your mixdown recorder has balanced XLR out- phantom power. Turn your mixer off before plugging
puts at the “pro” operating level of +4 dBu, then in or unplugging your talkback mic whether it’s a con-
order to use the TAPE INPUTs, you will have to adapt denser or a dynamic. It could save your mic!
the connector type, as well as attenuating the signal
Don’t feel left out if your console isn’t equipped
level by approximately 10 dB to avoid overloading.
with dedicated talkback circuitry. You can accom-
If the recorder has an output level control, just turn
plish the same thing by plugging a mic into a spare
it down. Otherwise, you’ll need to purchase or build
input channel and routing it to wherever you want to
an in-line attenuator. Alternately, you can connect
be heard.
the recorder outputs through an XLR-TRS cable to a
channel line input.
Main Outputs
Control and routing of the TAPE inputs varies
among models. Check the Control Room Source con- When we speak of the main outputs, we’re talking
trols in the Master section for particulars. about outputs from the left and right (stereo) bus-
ses. These outputs are controlled by the MAIN MIX
fader. This is where the fully mixed audio enters the
Auxiliary Return Inputs real world.
Auxiliary Returns are line-level inputs designed
The MAIN OUTPUTS on XLR connectors are dif-
for connecting the outputs of effects devices. They
ferential, providing an extra 6 dB of output level, up
can also be used to connect extra line-level audio
to +28 dBu.
sources. They’re balanced 1/4" TRS jacks, and will
accept signals from just about any pro or semi-pro The Main outputs are duplicated on impedance
effects device on the market. balanced 1/4" TRS jacks. These provide up to +22
dBu output level, and work equally well when con-
Typically, Auxiliary Returns from effects are routed
nected to either balanced or unbalanced inputs.
to the main L/R busses, but on certain models, they
When connected to a balanced input using a TRS
can also be easily routed to AUX sends or subgroup
plug, they appear to the input as a balanced output
busses for more flexibility.
with nearly all the benefits of a differential, balanced
source. When connected to an unbalanced input,
Talkback Microphone Input they appear as an unbalanced source, at the same
Some Mackie consoles are equipped with a con- output level as the balanced TRS outputs.
nector for a dedicated talkback microphone. A mic
The PPM series mixers, since they’re intended
plugged into this XLR jack can be routed to the main
primarily for use with their own internal amplifiers,
mix, allowing you to speak to the audience (“And
have only 1/4" unbalanced jacks for the main mix
now, let’s give a warm welcome to The SLOUGH-
outputs.
TONES - YEAH!!”) or via AUX Sends 1-2 to stage
monitors or headphones (“Hey Flash! Your D string is
flat!”).
The talkback mic has its own volume control and
routing switches located in the Master area of the
console.
The 8-Bus console has the talkback mic built
into the console. Just push the button and talk. In
addition to communication with the players, the
Talkback mic on the 8-Bus console can be sent to the

20 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2
Main Output Level Switch Don’t confuse this subwoofer output with its simi-
larly named neighbors, the SUB (subgroup) outputs.
Several compact mixer models
MAIN OUTS
are equipped with a switch that Tape Outputs
attenuates the XLR main outputs L

by 30 dB, bringing them down These unbalanced RCA jacks tap the MAIN MIX
to approximately the level of a +4
outputs to make simultaneous recording and sound
microphone. If you’re submixing MIC
reinforcement more convenient. They’re also handy
R
a group of instruments on stage MAIN
OUTPUT
for interfacing consumer recorders or semi-pro com-
LEVEL

(say a bunch of keyboards), by puter sound cards.

switching the output to MIC level,
you can send this submix back to Direct Outputs
the main mixer just as if it were
another microphone. It’s also handy for connecting to The 1/4" jacks on the 1604-VLZ PRO, 1642-VLZ
the one mic input they give you in the hotel meeting PRO, and 8-Bus, deliver the signal from nearly the
room. tail end of the channel path: post-TRIM, post-EQ,
post-LOW CUT, post-fader, and post-MUTE.
Mono Output The Onyx mixers also have direct outputs, but
Several Mackie mixers have a dedicated Mono they’re a bit different, both in form and function,
output for those requirements that seem to pop up and they’re labeled RECORDING OUTS. Rather than
now and then, demanding a monaural mix of a pains- using separate 1/4" jacks, these mixers use 25-pin D
takingly-created stereo panorama. The last thing you Subminiature (D-Sub) connectors, providing eight
want to do is start twirling all your carefully-placed fully balanced direct outputs on each connector.
PAN settings to one side. What to do? Stick a cable in The direct outputs on the Onyx series are more truly
the MONO output, hand the other end to Mr. Mono, “direct,” coming straight from the mic preamp stage
and you’re done. He’s got his mono mix and you’ve (which also incorporates the instrument and line in-
still got your stereo mix. The MONO output is nothing puts). These outputs are unaffected by the equalizer
more than an equal mix of the left and right MAIN or fader settings and are designed for the cleanest
MIX outputs. recording of the direct microphone signal.
Optional for the Onyx is a FireWire® (IEEE-1394)
Mono Level Control card, which provides direct outputs in digital format.
So, Mr. Mono comes running back, screaming about This is great for recording your live gigs with a laptop
the level being so loud that his camcorder is melting. computer.
Just reach for this knob and turn it down a bit. Just
Not all compact mixer models have direct outputs.
the thing for sending mono signals to mic inputs like
Some have direct outputs on only the lower-num-
camcorders, telephone interface boxes, even answer-
bered channels, and only the 8-Bus and Onyx have a
ing machines.
DIRECT output on every channel.
Subwoofer (75 Hz) Output Direct outputs are useful for sending the channel
The CFX series of mixers is MAIN OUT
straight to a track of a multitrack recorder. A direct
equipped with a unique feature – a output can also be used to send a single channel’s
mono output followed by a 3rd order L signal to an effects processor without using up an
75 Hz low-pass filter. It sums the left Auxiliary send.
and right main outputs and removes
everything but the deepest bass. R
Connect this output to a high-
powered subwoofer, and the music
police will be right over. The level of
the subwoofer output is fixed relative S
to the main outputs, so be sure that 75Hz
SUB OUT

your subwoofer amplifier (or powered

sub) has an adjustable input level for balancing the
bass level.

Compact Mixer Reference Guide 21

MIXER ANATOMY: CHAPTER 2

Bus/Subgroup Outputs PAN pan fully right.

In 4- and 8-Bus consoles, the output The 8-Bus console extends this trick by tripling the
L R

of the PAN control can be assigned to outputs of each of the eight busses to accommodate a
1
subgroup busses. The ASSIGN switches MUTE 24-track recorder.
(1-2, 3-4, L-R) direct the channel out- OL
On most Mackie mixers, subgroup busses can be
put to pairs of busses. The subgroup bus routed to the main outputs so that all channels as-
-20
outputs appear on the balanced 1/4" signed to that subgroup can be controlled by a single
TRS SUB OUT jacks. SOLO fader, retaining the balance and pan position set by
The subgroup outputs can be used the channel controls. You can individually mic each
1–2

to feed a mix of several channels (for of the background singers, assign their channels
example six mics on a drum kit) to a 3–4
to a single subgroup or pair, and use the subgroup
single pair of recorder tracks. fader(s) to bring the background vocals up in the
L-R mix when they’re needed.
OO

Bus Output Levels Not all models have the same SUB outputs, level
The subgroup bus output level on all controls, and routing capabilities. Input channels on
of the Mackie mixers is nominally 0 dBu. The output the CFX series cannot be routed directly to the MAIN
level of the busses is controlled by the bus faders. outputs, but must first be routed to a pair of sub-
group busses, which are in turn assigned to the MAIN
On the 8-Bus console, the bus output level is outputs by switches in the mixer’s Subgroup section.
switch-selectable between +4 dBu and –10 dBV, al- The PPM series has no SUB outputs since it has no
lowing you to properly match pro or semi-pro record- subgroups.
ers.
ALT 3-4 Outputs
The dual-purpose MUTE/ALT 3-4 switch on the
6 5 4 3
IN –10dBV
OUT +4dBu
1202/1402-VLZ PRO and Onyx 1220/1620 mixers is
a variation on the subgroup concept. When Greg
OPERATING
14 13 LEVEL 12 11 Mackie was designing our first compact mixer, he
wanted to include a mute switch for each channel.
22 21 20 19 Mute switches do just what they say — turn off the
+4dBu BALANCED / –10dBV UNBALANCED

SUBMASTER / TAPE OUTPUTS signal by sending it into oblivion. “Gee, what a waste,”
Greg reasoned. “Why not have the mute button route
Double (and triple) Bussing the signal somewhere else useful - like an alternate
stereo bus?”
The bus outputs on the 1642-VLZ PRO,
SR, and 8-Bus mixers have duplicate So MUTE/ALT 3-4 really serves two purposes: mut-
jacks to make connection to a multitrack ing (handy during a mixdown session or live show)
recorder easier. Even though the SR and 1642 are and signal routing. For multitrack recording and live
four-bus mixers with four subgroups, they have eight mixing, it serves as an extra stereo bus.
SUB OUT jacks for feeding eight recorder tracks, One difference between the ALT 3-4 outputs and
thanks to a trick called Double Bussing. BUS OUTs 3 and 4 on the larger consoles is that
SUB OUTS 1 and 5 carry the same signal, as do 2 there’s no output level control for those busses
and 6, 3 and 7, and 4 and 8. By connecting those eight – they run at unity gain. Another difference is that
jacks to the eight inputs of your recorder, you can it’s either/or routing – a channel can’t be assigned to
route any input channel to any track. both the MAIN and ALT outputs simultaneously. But
like the true 4-bus consoles, the ALT busses can be
To record onto Track 1, assign the input channel to routed to the MAIN outputs, serving as a submaster
Bus 1 by pressing the 1-2 ASSIGN button and turning pair.
the PAN control fully left. On the recorder, put Track
1 into the Record mode, being sure that Track 5 is in To MUTE channels in the main mix, leave the ALT
the Safe or Play mode. To record on Track 5, use the 3-4 outputs disconnected. Pressing the MUTE/ALT
same bus assignment on the mixer, but put Track 5 in 3-4 button switches the channel signal from the
Record. To record on Track 2 or 6, ASSIGN to 1-2 and MAIN to the ALT 3-4 busses, sending it off to never-
never land, disconnecting it from the MAIN MIX, and

22 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2
effectively muting its input. Stage monitors are almost always fed from a pre-
fader send, so that the engineer can create a mix
To use ALT 3-4 as output busses, just connect the
for the musicians on stage and leave it alone once
ALT 3-4 outputs to whatever destination you desire.
they’re happy. (Turn the drummer up really loud in
Pressing the MUTE button will remove the channel
his monitor and he’ll think he’s really loud in the
signal from the MAIN bus and route it to the ALT 3-4
house.) Then you can mix the house according to
outputs.
your good taste.
The ALT 3-4 outputs are a good way to feed a mul-
In larger sound reinforcement systems, pre-EQ
titrack recorder when you only need to record one or
sends for the monitors are nearly always preferred
two tracks at a time, or a good way to feed a stereo
since there’s usually an outboard equalizer between
sound card in a computer.
the console and the monitor amplifier. If the moni-
tors are fed after the channel equalizer, an EQ boost
AUX Send Outputs to bring out an instrument in the house might cause
The Auxiliary Send section is like a bunch of mono a blast of feedback on stage. Also, musicians don’t
mixers, one for each Auxiliary output. The AUX like to hear you messing with “their tone.”
controls send a copy of the channel signal to the AUX Studio headphone cue feeds are similar to stage
bus where the signals are mixed and sent to the AUX monitors only there’s no risk of feedback, so fidelity
output. On some of our mixers, these controls are can come first. If an instrument sounds better in the
labeled MONITOR and EFX (effects) since those are control room with EQ, it will probably sound better
common uses. to the musician too, so post-EQ monitor sends are
usually preferred. A pre-fader send is a good idea,
Pre and Post Sends though, since a musician playing an overdub may
Auxiliary Sends are designated as PRE or POST. want to hear a mix that helps him focus on his part,
Pre or post what? POST always means post-fader, while the producer will want to hear a well balanced
PRE is always pre-fader. The output level of a PRE mix in the control room.
send is independent of the position of the channel
Effects sends are almost always post-fader and
fader, while the level of a POST send follows the
post-EQ. Generally you want to send a signal to the
channel fader. Both come after the LOW CUT filter
effects processor in proportion to its level in the mix.
(if any) but on some models, the PRE send is taken
When you turn something down in a mix, you want
before the equalizer section while on others it comes
the effect level to drop along with it. Sometimes,
after the EQ. It may come either before or after the
though, you may want the “dry” signal to fade out,
MUTE switch. Here’s a summary for all of the Mackie
leaving only the “effect”-ed version. Use a Pre-fader
mixers of where the Pre-fader AUX sends are taken:
send to achieve this.
Source for PRE Sends Having the pre-fader sends fed after the MUTE
Model EQ Mute switch is very handy for live sound applications.
When you mute a channel, it’s muted everywhere.
1202/1402-VLZ PRO Post Pre
1604-VLZ PRO Pre Pre PRE/POST Switches
1642-VLZ PRO Pre Pre Some AUX sends are hardwired one way or the
Onyx Post Pre other, and are labeled as such on the panel. Some
models have switches that allow you to change the
CFX Post Post feed point of the Send from the front panel.
DFX Pre Post
MUTE
PAN ASSIGN
SR Post Post INPUT TRIM INSERT
LOW
CUT
EQ
FADER

8-Bus Switched Post 'PRE' SIGNAL 'POST' SIGNAL

AUX 1

PPM Pre NA PRE SWITCH AUX 2

That’s quite an assortment. The variations reflect

both the most likely application, and what was in
favor at the time the mixer was designed. Here are
some common preferences:

Compact Mixer Reference Guide 23

MIXER ANATOMY: CHAPTER 2
AUX Send Shift easy reach of the mixer. By plugging a normally open,
latching (push-on-push-off) foot switch into the
Some Mackie consoles have six AUX SEND busses EFX FOOT SWITCH jack, you can mute the effect
but only four AUX knobs. The SHIFT button selects return without leaving your performing position. If
whether their associated knobs send the channel the mixer is in sight, the lighted EFX BYPASS LED
signal to AUX outputs 3 and 4 or outputs 5 and 6 on a will remind you of why you’re no longer in the Grand
channel-by-channel basis. Canyon.
Using AUXes with Effects If you’re using an outboard effects pro-
cessor on the PPM instead of the EMAC,
Here’s the signal flow from the AUX send, through
that will also be bypassed when either the
the AUX output, to a reverb unit, and back to the mix
front panel or foot switch is activated. On the CFX
through the AUX Return jack.
and DFX, however, the bypass switch comes ahead of
the EFX RETURN 2 jacks, so an external processor
FADER
•
AUX
•
• coming in to the mix at that point will not be affected
AUX

•
BUS
•
by the bypass foot switch.
•
AUX
SEND
AUX
RETURN Plugging in a foot switch disables the
• •
MAIN
front panel EFX BYPASS switch.
BUS

IN
REVERB

OUT
Control Room Output
When recording, it’s convenient to have an output
This is sometimes called a “parallel” effect con- with its own volume control that’s dedicated to con-
nection, since the path of the processed signal is in trol room listening. Control Room outputs are on 1/4"
parallel with the dry signal path. balanced TRS jacks (unbalanced on the 8-Bus) and
are fed from the Control Room Level control. This al-
Built-in Effects lows you to crank the playback level so the drummer
can hear it, or turn it down to answer the telephone,
The CFX, DFX. and PPM series mixers have a built
all without disturbing the MASTER level, which
in digital effects processor (EMAC). The input of the
you’ve set to send the proper level to the mixdown
EMAC is normally connected to the EFX bus (EFX
recorder.
2 in the CFX), and the output is normally returned
to the MAIN bus. The EFX send and return jacks on The source for the Control Room output is selected
these mixers have normalling switch contacts – in- by switches in the Master section of the console. The
serting a plug disconnects the normal send/return Main left/right outputs are always available to the
loop through the EMAC so that you can use them control room monitor. Other choices, depending on
with an outboard processor. the mixer, are the subgroups, ALT 3-4 bus, playback
from a stereo recorder, Mix B, or another external
With some clever cable juggling you can even
source such as a CD player.
use the EMAC processor as an outboard effect for
another mixer.
Headphone Output
EFX Foot Switch and Bypass The Headphone output is another copy of the
We’ve included some features on the effects- Control Room output (the 8-Bus offers several other
equipped mixers that will be welcomed by the choices) followed by an amplifier capable of driving a
musician or band working without a sound engineer. set of headphones to a comfortable, no, a pretty darn
The Grand Canyon reverb might have sounded great loud level.
on that ballad you just finished, but it really sounds WARNING: When we say the headphone
dumb on your speaking voice, when you’re introduc- amp is loud, we’re not kidding. It can
ing the next song. It’s handy to be able to quickly kill cause permanent hearing damage (and
the effects processor and then turn it back on when headphone damage, too). Even intermediate levels
it’s time for the next song. may be painfully loud with some earphones. BE
The EFX BYPASS switch on the front panel mutes CAREFUL!
the signal to the effects processor when you’re in

24 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2
On some models, the headphones and control room You can also insert a signal processor such as a
share the same level control; on others, there’s a delay, flanger, or reverb unit in the channel path to
separate control for headphone level. process the source coming into that channel. This is
sometimes called a “serial” effect hookup since it’s in
Some models have two headphone jacks. The two
series with the signal path.
jacks on the 1642-VLZ PRO are fed from the same
point, and both follow the same Phones level control. Since most people who need only a small mixer,
The 8-Bus console has two completely independent don’t have racks full of processing gadgets, our small-
headphone outputs, each having its own level control est mixers don’t have Inserts on every channel. The
and source selector for two separate mixes to its larger ones do.
headphone jacks.
The INSERT jack is a 1/4" TRS type, but in this
instance, the two jack contacts are used as an output
Studio Output (8-Bus) (send) from the preamp and an input (return) back
The Studio Output normally feeds an amplifier and into the remainder of the channel strip. Switch
speakers (or powered speakers) in the studio, so that contacts built into the jack provide a “normal” con-
the musicians can hear a playback without coming nection from send to return when there’s no plug
into the control room. These carry the same signal as inserted. When you push a plug all the way in, this
the Control Room outputs, but have an independent connection is broken, and you have access to the
level control so you can adjust the playback volume channel insert points through the jack.
to suit the listeners.
The tip of the plug connects to the SEND, and the
The 8-Bus TALKBACK microphone can be routed ring connects to the RETURN. Since we’re using only
to the Studio output, so that you can talk to the play- one contact of the jack for each connection, con-
ers through the studio monitor speakers. nections to and from the INSERT are unbalanced.
The send is a low impedance line-level output that
WARNING: When you have mics live in will drive any pro or semi-pro processing device. The
the studio, they’ll also be live in the studio RETURN is a moderate impedance line-level input
monitors if the Studio output control is that can be driven by almost any device.
turned up. In the extreme case, you’ll get feedback,
but you don’t want to record the speaker outputs ei- You can buy an Insert cable off the rack at your lo-
ther. When tracking, be sure to turn the Studio Level cal music store, or build one. Here’s how it’s wired:
control down between playbacks.
SEND to processor
ring “tip”
tip (TRS plug)
The Studio Output jacks can be used with a second sleeve

amplifier and speakers in the control room, so you

can compare the mix on your high grade monitors This plug connects to one of the “ring”
mixer’s Channel Insert jacks. RETURN from processor
with the boombox speakers the rest of the world
listens to. To switch between the two, turn one level
control down and the other one up, or easier, use an Tip = Send (Output to effects device)
external monitor A/B switch. Ring = Return (Input to effects device)

Mix B Output (8-Bus) Sleeve = Common Ground (Shield connects to all

three sleeves
The MIX-B jacks are 1/4" unbalanced outputs that
carry the Mix B signal. We’ll cover Mix B in depth Here’s how to hook an outboard signal processor in
later on, but briefly, it’s an independent stereo mix line with the channel path (a “serial” connection):
that’s usually used for monitoring the multitrack
recorder returns when tracking. RING
TIP

Channel Inserts
The channel INSERT jacks allow you to break the IN
vu

OUT

channel signal path right after the mic preamp stage

and its associated TRIM control (the low-cut filter
too on some mixers) and insert a device such as a
compressor, equalizer, or de-esser into the chain.

Compact Mixer Reference Guide 25

MIXER ANATOMY: CHAPTER 2
Insert Jack Tricks – Direct Outputs and If you want to use an external mic preamp with
your mixer (boo-hoo!), or perhaps a Voice Processor
Inputs (combination preamp, compressor, equalizer, de-es-
Besides being used for adding outboard signal pro- ser, and automatic word rememberer) you can com-
cessors to the channel signal path, the INSERT jacks pletely bypass the fabulous world famous Mackie mic
can be used as pre-EQ direct outputs. preamp by bringing the signal from your outboard
preamp into the mixer through the INSERT Return.
It’s a fact - Mackie mic preamps have become so
famous that people buy our mixers just to have the To do this, you’ll need a custom cable with a stereo
preamps in their arsenal. To use a preamp by itself, (TRS) plug wired with the hot lead connected to the
with nothing else in the signal path to the recorder, RING, the shield connected to the sleeve, and noth-
use the INSERT SEND to connect it directly to the ing connected to the tip.
recorder’s input.
If you insert a plug into the jack gently, you’ll feel
two “clicks;” the first as the plug tip passes the ring
Channel Insert jack
contact, and the second when it settles into the tip
contact. If you use a “mono” (TS) plug and insert it
only as far as the first click, the ring contact will con- Plugging this all the way into the jack will break
nect to the plug, sending the preamp out to whatev- the normalling contacts, replacing the Mackie pre-
er’s on the other end of the cable. amp with the output from the outboard unit.

But waitacottinpickinminnit! The ring is the This connection also bypasses the TRIM
return, isn’t it? control, so you’ll need to adjust the Output
Level control of your external preamp
Yes, but with the plug inserted only halfway, the when using the Level-Setting Procedure. It’s still im-
normalling switch contacts in the jack don’t open portant to check the channel level, even when using
– send and return are still connected. Since the an outboard unit as the front end.
normal connection is still intact, the signal passes
through the channel path as well as coming out the Utility Output (CFX Series)
INSERT jack as a direct output. If you’re using the
console for sound reinforcement and recording each The stereo signal from the UTILITY OUT 1/4" TRS
input separately to a multitrack recorder, this is the jacks is the same as the MAIN output, but with its
cleanest way to feed the recorder inputs. own level control, allowing you to set the level to
an auxiliary set of speakers or a recorder without
Here’s what an Insert looks like up-close when disturbing the main mix level.
used as a Direct Output:
These outputs are handy for driving “fill” speakers
in areas of a room that aren’t adequately covered by
MONO PLUG the main speakers. Or you might use them to feed
Channel Insert jack speakers in the lobby, or the Green Room. (Regard-
less of the color, every concert venue has a Green
Direct out with no signal interruption to master.
Insert only to first “click.” Room – it’s where the musicians and hangers-on
hang out.)
NOTE: If you want to keep the preamp signal out UTILITY outputs are taken after the main fader, so
of the mix (you will if you’re monitoring the returns adjustment of the MAIN level control will affect the
from the recorder), push the plug all the way in. That UTILITY output level.
will open the normal contacts.

MONO PLUG
Channel Insert jack

Direct out with signal interruption to master.

Insert all the way in to the second “click.”

26 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2

PPM Series Outputs the total impedance isn’t lower than 2 ohms. Chances
are, however, that the efficiency of the speakers will
The PPM mixers have two power amplifiers built be different enough that they’ll produce noticeably
in. A flexible arrangement of switches and jacks allow different volumes. This may or may not be what you
you to use those two amplifiers for any combination want.
of main and monitor speakers.
Note that the stereo and mono PPM mixers have
SPEAKER Out (PPM) different labels on the speaker connectors. They also
have different options for routing MAIN and MONI-
These 1/4" TS jacks carry the outputs of the power TOR mixes to those two amplifiers.
amplifiers.
There’s a convenient pushbutton to select the
There’s power behind these jacks – 125 most common configurations. There are also patch-
to 600 watts depending on the model. ing jacks that allow you to rearrange things to your
Don’t connect them to anything other than liking, or add an external power amplifier for more
passive speakers – not active speakers, not a record- flexibility. See the PPM Applications for some sugges-
er, not another mixer. PASSIVE SPEAKERS ONLY! tions
Caution: Don’t use standard guitar POWER AMP ROUTING

cables to connect your speakers. Guitar STEREO MAINS

LEFT = MAIN
408S 2 X 250W STEREO
RIGHT = MONITOR

cords are designed for line level signals EFFECTS

(OVERRIDES INTERNAL EFX) MAINS MONITOR

and low currents, not the high currents and voltages

EFX FOOT L POWER R POWER LINE
SWITCH SEND AMP IN AMP IN OUT

of speaker levels. Use heavy duty speaker cables—at

LEFT RETURN RIGHT RETURN L MIXER OUT R MIXER OUT COMPRESSOR

least 16 gauge. The heavier (lower gauge number) OUT

IN

the better. Thin speaker cables equal thin sound!

There are two SPEAKER OUT jacks for each ampli-
On the stereo mixers, the choices for Power Amp
fier. The jacks are wired in parallel.
routing are:
POWER AMP ROUTING - In
AMP 1 – MAIN Mono (left + right)
AMP 2 – Monitor
POWER AMP 1 / MAIN POWER AMP 2 / MONITOR
Or
SPEAKER OUT SPEAKER OUT POWER AMP ROUTING - Out
OUTPUT POWER: 250 WATTS / CHANNEL
MINIMUM SPEAKER LOAD: 2 OHMS / CHANNEL AMP 1 – MAIN Left Channel
AMP 2 – MAIN Right Channel
When you connect two speakers to a single ampli- POWER AMP ROUTING
AMP 1 AMP 2
MAIN MAIN 408M 2 X 250 WATTS
MAIN MONITOR

fier, the load presented to the amplifier is the parallel EFFECTS

MAINS
impedance of both speakers. The total (parallel) (OVERRIDES INTERNAL EFX)
EFX FOOT
SWITCH SEND
POWER
AMP 1 IN
POWER
AMP 2 IN
MONITOR
LINE
OUT

impedance must be two ohms or greater.

RETURN MIXER LINE OUT

• Two 8 ohm speakers in parallel equals 4 ohms. OUT

IN
COMPRESSOR

• Two 4 ohm speakers in parallel equals 2 ohms.

The general formula for impedance in parallel is: On the mono mixers, the choices are:
POWER AMP ROUTING - In
1 AMP 1 – MAIN
Z etc.
1 1 1 AMP 2 – Monitor
+ + Or
Z1 Z2 Z3
POWER AMP ROUTING - Out
In electronics, Z is the symbol for impedance. We AMP 1 – MAIN
don’t have a clue as to what word Z stands for. AMP 2 – MAIN

Can you plug speakers with different impedances On both the mono and stereo models, when the
into the two jacks same amplifier? Sure, as long as ROUTING switch is in the Out position, both power

Compact Mixer Reference Guide 27

MIXER ANATOMY: CHAPTER 2
amplifiers are dedicated to the MAINs. If you want to POWERING UP! – Power supplies and Ac-
connect a stage monitor, you’ll either need to use a
powered speaker or an external power amplifier con- cessory Power
nected to the MONITOR LINE OUT jack.
Compact Mixers
The speaker outputs are affected by the MAIN
MASTER level control and the MAIN Graphic Equal- Of course you have to be able to turn your mixer
izer. on – but you don’t want to turn it off inadvertently,
either. To keep such accidents from happening, we
MONITOR Line Out (PPM) hide the POWER switch on the rear panel of all of the
Mackie compact mixers.
This is a 1/4" unbalanced jack with a line-level
signal suitable for driving powered speakers or power There’s a power-on indicator on the front panel.
amplifiers. The signal is fed pre-fader and pre-EQ Check your mixer’s manual for its location if it’s not
from the mixer’s monitor bus. The MONITOR out- obvious.
put has its own low-cut (rumble) filter, MONITOR
At Mackie, our compact mixers have internal
MASTER volume, control and MONITOR graphic
power supplies. A standard IEC connector and power
equalizer.
cord connects the mixer to an AC outlet. The power
MIXER LINE OUT (Mono) cord is an industry-standard item, so if you leave it
behind, you won’t have to look too far for a replace-
L or R MIXER OUT(Stereo) ment. Most computers use the same power cord, and
These are 1/4" unbalanced line-level jacks that you can buy one at most computer or office supply
provide the main mixer output(s). The jack is fed stores as well as your local Radio Shack or music
from the MAIN mixer bus (left and right busses in store.
the stereo version), following the MAIN MASTER All Mackie mixers will operate equally well from
control and MAIN graphic equalizer, and just ahead 50 or 60 Hz power. The Onyx mixers have “world
of the POWER AMP IN jack(s). friendly” power supplies that operate from 100 to
You can connect the MIXER OUT to an external 240 VAC (and they even ship with two power cords
power amplifier for more power and more speak- to accommodate US and European outlets). Other
ers. Plugging into these jacks does not interrupt the models are designed for only a single AC line voltage,
signal flow to the PPM’s built-in power amplifiers. depending on the country where you bought it. If you
travel world-wide, you’ll need a step-up or step-down
POWER AMP IN (PPM) transformer in countries that have a different line
voltage than what’s specified for your mixer.
This is a 1/4” jack that accepts an unbalanced
line-level signal. Whatever signal you plug into these 8-Bus Console
jacks is combined with the internal mixer signals and
routed to the power amplifiers. You could connect the The 8-Bus console has an outboard power supply
LINE OUT jacks from another mixer (even another with the main power switch on its front panel. The
PPM) to the POWER AMP IN jacks to increase the switch is also the power-on indicator.
number of channels available. Connect the power supply to the mixer using the
You could connect the outputs from the opening special multiconductor cable provided, then connect
band’s mixing board to these inputs. This way you the AC power to the power supply.
don’t have to set up two complete sound systems
— the other band can use their mixer together with
your PPM, using its amplifiers and your speakers.
On later production PPM mixers, these jacks
are wired in the “normalled through” configuration
allowing you to use an Insert Cable for patching in
an outboard graphic equalizer, limiter, or crossover
network.

28 Compact Mixer Reference Guide

 MIXER ANATOMY: CHAPTER 2
BNC Lamp Socket
Those decidedly non-audio-looking BNC connec-
tors on the top panel of several Mackie mixers are for
mounting and powering gooseneck lamps so you can
find the knobs in the dark. The BNCs are wired with
the center post at +12 VDC.

We recommend LittleLite lamps 12" gooseneck

#12G or #12G-HI (a high-intensity version) for the
smaller consoles, and the 18G-HI with an 18" goose-
neck for the larger mixers. Buy them from your pro
audio dealer.
Now that we’ve worked our way through the
functions of most of the parts of a console, let’s get
physical and take it section by section, looking at the
actual hardware. We’ll continue to point out unique
features of Mackie mixers, but with what you learn
here, you should be able to walk up to just about any
mixer and understand it in just a couple of minutes.

Compact Mixer Reference Guide 29

MIXER ANATOMY: CHAPTER 2

Notes

30 Compact Mixer Reference Guide