Mackie Musical Toy Instrument 1604 User Manual

1604VLZ4  
16-Channel 4-Bus Compact Mixer  
O W N E R ’ S M A N U A L  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Contents  
DIMENSIONS.................................................. 31  
TRACK SHEET.................................................. 32  
BLOCK DIAGRAM............................................ 34  
Please write your serial number here for future  
reference (i.e., insurance claims, tech support,  
return authorization, make dad proud, etc.)  
Purchased at:  
Like us  
Follow us  
Date of purchase:  
Watch our dang videos  
Owner’s Manual  
Part No. SW0972 Rev. A 06/13  
©2013 LOUD Technologies Inc.  
All Rights Reserved.  
3
Download from Www.Somanuals.com. All Manuals Search And Download.  
Features  
Introduction  
16-channel mixer featuring our signature  
high-headroom, low-noise design  
A legend in compact mixer design, the 1604VLZ4  
now combines the proven performance of Onyx preamps  
with the no-compromise high-headroom/low-noise  
design that made the 1604 an industry mainstay.  
16 boutique-quality Onyx mic preamps  
• Ultra-wide 60 dB gain range  
• 128.5 dB dynamic range  
All 16 channels feature an Onyx mic pre, line  
input and insert in a compact 4-bus design built  
for application flexibility and professional performance.  
Plus, it is truly “Built-Like-A-Tank” with a ridiculously  
rugged solid-steel chasis that includes high-contrast  
controls for ultimate tactile control.  
• +22 dBu line input handling  
• Extended frequency response  
• Distortion under 0.0007% (20 Hz - 50 kHz)  
Improved RF rejection, perfect for broadcast  
applications  
Phantom power for condenser mics  
Found in countless professional broadcast and post  
facilities and easily the most proven band-friendly  
analog mixer ever, the 1604 stands alone in the world  
of compact mixing.  
16 high-headroom line inputs with  
+4/–10 operation control  
16 balanced inserts perfect for integrating  
outboard gear  
How To Use This Manual  
3-band EQ with sweepable midrange  
18 dB/oct 75 Hz low-cut filter on mic input  
channels  
After the introduction, a getting started guide will  
help you get things set up fast. These are followed by  
hookup diagrams which show some typical setups.  
Four aux sends, level, pan and solo and  
overload/mute LEDs on each channel  
Next is a detailed tour of the entire mixer.  
The descriptions are divided into sections, just  
as your mixer is organized into distinct zones:  
Four stereo returns, eight direct outs  
and four group/bus outputs  
60 mm long-wearing log-taper faders  
Patchbay  
Control room / phones multi-input source  
matrix  
Channel Strip  
Output Section  
High-resolution 12-segment stereo meters  
Sealed rotary control resist dust and grime  
Throughout these sections you’ll find illustrations  
with each feature numbered and described in nearby  
paragraphs.  
“Built-Like-A-Tank” rugged steel chassis with  
powder-coat finish  
This icon marks information that is critically  
important or unique to the mixer. For your own  
good, read them and remember them.  
High-visibility, high-contrast controls deliver  
convenient “at-a-glance” visual feedback  
Rack-mountable design with three physical  
configurations via Rotopod accessory  
(sold separately)  
This icon will lead you to some explanations  
of features and practical tips. They usually  
have some valuable nuggets of information.  
Multi-voltage power supply for worldwide use  
Need help with your mixer?  
• Email us at: [email protected].  
Telephone 1-800-898-3211 to speak with one of our splendid technical support chaps  
(Monday through Friday, normal business hours, Pacific Time).  
4
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Set the levels  
Getting Started  
It’s not even necessary to hear what you’re doing to  
set optimal levels. But if you’d like to: Plug headphones  
into the phones output jack, then turn up the  
CR/phones knob just a little.  
We realize that you must be really keen to try out  
the mixer. Please read the safety instructions on page  
2, then have a look through some of the features and  
details in this manual.  
1. Turn on the mixer by pressing the top edge of  
the power switch.  
Setup  
2. For one channel, press the solo switch in.  
Use the mixer in a nice clean and dry environment,  
free from dryer lint and dust bunnies.  
3. Engage the mode switch in the master  
section. A green level set light will turn on.  
4. Play something into that input at real-world  
Zero the controls  
levels.  
5. Adjust that channel's gain control until the  
left main meter stays around the 0 dB LED  
(marked “level set”) and never goes higher  
than “+7.”  
1. Fully turn down all the knobs and faders  
to minimum, except for the channel EQ  
and pan controls, which should be centered.  
2. Make sure all buttons are in the out position.  
6. Disengage the channel's solo switch.  
7. Repeat steps 2 to 6 for the remaining channels.  
8. Turn up the channel fader to the “U” mark.  
Connections  
1. Make sure the AC power switch is off before  
making any connections.  
9. Slowly turn up the main mix fader until you  
hear the signals in the headphones.  
WARNING: Before plugging the AC power  
cord into the mixer, make sure the VOLTAGE  
SELECTOR switch is set to the same voltage  
as the local AC mains supply (see page 13).  
10. If needed, apply some channel EQ wisely.  
11. Adjust the channel faders to get the best mix.  
Keep the gain controls and levels fully down  
on unused channels.  
2. Push the linecord securely into the IEC  
connector on the rear panel, and plug it into a  
3-prong AC outlet. The mixer may accept any  
AC voltage ranging from 100 VAC to 240 VAC.  
12. During the performance, if you notice a channel  
OL LED turning on during peaks, carefully turn  
down that channel's gain control until OL does  
not turn on.  
3. Plug a balanced microphone into one of the mic  
XLR (3-pin) connectors. Or connect any  
line-level signal (keyboard, or guitar preamp)  
to a line input jack using a TS or a TRS  
1/4" plug.  
Things to Remember  
Never listen to loud music for prolonged  
periods. Please see the Safety Instructions on  
page 2 for information on hearing protection.  
4. If your microphone requires phantom power,  
turn on the 48V phantom power button.  
Always turn down the main mix fader and  
control room/phones knob down when making  
connections to the mixer. Better yet, turn off  
the power.  
5. All 16 channels have insert jacks that can be  
used to connect an external effects or dynamics  
processor into the signal chain.  
When shutting down, turn off any power  
amplifiers or powered speakers first. When  
powering up, turn them on last. This will  
reduce the chance of turn-on or turn-off  
thumps.  
6. Connect the TRS 1/4" main outputs of the  
mixer to the line level inputs of your amplifier  
(with speakers already attached) or to the line  
level inputs of powered speakers.  
Save the shipping box!  
5
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Hookup Diagrams  
Synth  
Headphones  
Vocal  
mics  
Vocal  
mics  
Drum microphones  
Stereo Guitar Effects  
Stereo Guitar Effects  
Headphone amp  
(Connected to the  
phones jack on the  
front of the mixer)  
Stereo Compressor  
Stereo Compressor  
Stereo Compressor  
and Stereo EQ  
Multi-track  
Digital Recorder  
Stereo Tape Deck  
Digital Reverb  
Digital Delay  
MR8mk3  
Laptop  
studio monitors  
The rhythm and lead guitars play through stereo effects processors plugged into the line inputs of  
channels 1 and 2. Microphones are connected to the mic inputs of channels 3-14 with vocal compressors  
connected to the channel 3-4 and 13-14 insert jacks. [Drums are mic'd on channels 5-12]. A bass guitar  
is connected to the line input of channel 15, while a synth is connected to the line input of channel 16.  
A stereo compressor and stereo graphic EQ are connected to the L/R main inserts. Digital reverb and  
delay processors are connected to aux sends 1 and 3, with the aux sends set to post-level. Effects are  
added to the main mix via the stereo return inputs, and adjusted with the stereo return level control.  
There are a multitude of recording possibilities geared for both analog purists and digital hounds.  
There are three examples listed here, but feel free to experiment! (1) the RCA tape inputs and outputs are  
connected to a stereo tape deck. It's an easy way to get a stereo recording of the entire band, as well as  
listening to playback (over tape), (2) the eight direct outputs are connected to the eight inputs of a multi-  
track digital recorder, and (3) the four subgroup outs are connected to the laptop. Again, there are many  
choices for recording. Do what works for you and your setup!  
A pair of MR8mk3 studio monitors are connected to the control room outputs to listen to playback of  
your latest masterpiece.  
Recording System  
6
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Synth  
Vocal  
mics  
Vocal  
mics  
Drum microphones  
Headphones  
(Connected to the  
phones jack on the  
front of the mixer)  
Stereo Guitar Effects  
Stereo Guitar Effects  
Stereo Compressor  
DLM8 loudspeakers  
Stereo Compressor  
DLM8 Stage Monitors  
Digital Reverb  
Digital Delay  
Laptop  
Stereo Compresor  
and Stereo EQ  
Stereo EQ  
DLM12S subwoofers  
The rhythm and lead guitars play through stereo effects processors plugged into the line inputs of  
channels 1 and 2. Microphones are connected to the mic inputs of channels 3-14 with vocal compressors  
connected to the channel 3-4 and 13-14 insert jacks. [Drums are mic'd on channels 5-12]. A bass guitar  
is connected to the line input of channel 15, while a synth is connected to the line input of channel 16.  
A stereo compressor and stereo graphic EQ are connected to the L/R main inserts. The 1/4" L/R main  
outs connect to a stereo graphic EQ before connecting to a pair of DLM12S powered subwoofers which  
are connected to a pair of DLM8 powered loudspeakers to please your audience.  
Aux sends 1 and 2 are connected to DLM8 powered loudspeakers, used as stage monitors to please  
the band. Digital reverb and delay processors are connected to aux sends 3 and 4, with the aux sends  
set to post-level. Effects are added to the main mix via the stereo return inputs, and adjusted with the  
stereo return level control.  
The RCA tape inputs and outputs are connected to a laptop. It's an easy way to get a stereo recording  
of the live show for posterity and crank your featured playlist over the PA between bands.  
Live Stereo PA System  
7
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Converting To Rackmount Mode  
Not only is the 1604VLZ4 a compact, professional-  
quality tabletop mixer...it’s rack-mountable!  
7. Carefully install the pod-mounting screws in  
their new locations [d].  
The unique rotating input pod makes this possible.  
8. Install the rack ears that came with the mixer,  
using the supplied packet of screws. These  
screws are a bit longer than the ones you have  
to take out. The rack ears may be installed in  
either of two depths as shown at the bottom  
of this page: [e] mixer’s surface flush with the  
rack rails, like ordinary rackmount equipment,  
or [f] mixer’s surface sunken into the rack, to  
protect the knobs from being bumped.  
With a trusty phillips screwdriver, nerves of steel, grit,  
determination, charming good looks and a few moments  
of your valuable time, it may be converted from desktop  
mode (from the factory) to rackmount mode:  
1. Turn off the power and remove ALL the cords  
from the mixer — power cord, audio, lamps,  
everything.  
2. Place the mixer, face down, on a clean soft  
surface, like a blanket or very large dog.  
NOTE: If you remove the rack ears at a later date,  
use the original (shorter) screws to secure the  
sides.  
3. Remove the four screws securing the cable  
cover [a] and set the plate aside.  
An optional accessory called the Rotopod-VLZ is  
available and may be used in desktop or rackmount  
installations. It will put the patchbay jacks on the  
same plane as all the knobs, buttons and faders.  
This is a lifesaver in applications that demand frequent  
repatching, and costs a heck of a lot less than an  
external patchbay, not to mention all the interface  
and patch cords. Please visit your dealer for more  
exciting details. Be sure to order the “VLZ4” version  
so you don’t end up with the one for the classic CR-1604!  
4. Replace two of the screws; the ones at the pod  
end of the mixer [b].  
5. Remove two pod-mounting screws on each side  
of the mixer [c].  
6. Gently pull the pod away from the slots, rotate  
it, and place it, tabs first, into the rackmount  
tabs [d], located on the underside of the main  
chassis. Be careful not to constrict or pinch any  
of the ribbon or power cables.  
remove  
screws  
replace  
screws  
remove  
plate  
rackmount  
tab slots  
rotate  
pod  
remove  
screws  
replace  
screws  
use the longer screws  
that come in a little bag  
use the longer screws  
that come in a little bag  
sunken  
position  
flush mount  
8
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Patchbay Description  
1
At the risk of stating the obvious, this is where you  
plug everything in: microphones, line-level instruments  
and effects, headphones, and the ultimate destination  
for your sound: PA system, DAW, etc. A few of the  
features described in this section are on top of the  
mixer, but most are out back on this “pod.”  
The XLR inputs are wired as follows:  
Pin 1 = Shield or ground  
Pin 2 = Positive (+ or hot)  
Pin 3 = Negative (– or cold)  
Professional ribbon, dynamic, and condenser mics all  
sound excellent through these inputs. The mic/line  
inputs will handle any kind of level you can toss at  
them, without overloading.  
See Appendix B (page 27) for further details and  
some rather lovely drawings of the connectors you  
can use with the 1604VLZ4.  
Not every instrument is made to connect directly to  
a mixer. Guitars commonly need a Direct Injection (DI)  
box to connect to the mixer's mic inputs. These boxes  
convert unbalanced line-level signals from your guitar,  
into balanced mic-level outputs, and provide signal and  
impedance matching. They also let you send your gifted  
guitar renditions over long cables or audio snakes,  
with minimum interference or high-frequency signal  
loss. Ask your dealer or guitar maker about their  
recommendations for a good DI box.  
EZ Interface  
Concerned about levels, balancing, impedances,  
polarity, or other interface goblins? You can patch  
anything almost anywhere on the 1604VLZ4, with  
nary a care. Here’s why:  
Every input and output is balanced (except  
insert, phones and RCA jacks).  
Every input and output will also accept  
unbalanced lines (except XLR jacks when  
phantom power is on).  
Phantom Power  
Most modern professional condenser mics are  
equipped for phantom power, which lets the mixer  
send low-current DC voltage to the mic’s electronics  
through the same wires that carry audio. (Semi-pro  
condenser mics often have batteries to accomplish the  
same thing.) “Phantom” owes its name to an ability to  
be “unseen” by dynamic mics (Shure SM57/SM58, for  
instance), which don’t need external power and aren’t  
affected by it anyway.  
Every input is designed to accept virtually any  
output impedance.  
The main left and right mix outputs can deliver  
28 dBu into as low as a 600 ohm load.  
All the other outputs can deliver 22 dBu into  
as low as a 600 ohm load.  
All the outputs are in phase with the inputs.  
All we ask is that you perform the level setting  
procedure [page 5] every time you patch in a new  
sound source. So stop worrying and start mixing!  
The 1604VLZ4’s phantom power is globally controlled  
by the phantom [22] switch on the rear panel.  
(This means the phantom power for all channels  
is turned on and off together.)  
1. Mic Ins  
Never plug single-ended (unbalanced)  
microphones, or ribbon mics into the mic  
input jacks if the phantom power is on.  
This is a female XLR connector that accepts a  
balanced mic or line level input from almost any type  
of source. These Onyx mic preamps feature higher  
fidelity and headroom rivaling any standalone mic  
preamp on the market today. These circuits are  
excellent at rejecting hum and noise.  
Do not plug instrument outputs into the  
mic input jacks with phantom power on  
unless you know for certain it is safe to do so.  
9
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
6
5
4
2
2. Line Ins  
4. Insert  
These 1/4" jacks share circuitry (but not phantom  
power) with the mic preamps, and can be driven by  
balanced or unbalanced sources at almost any level.  
You can use these inputs for virtually any signal you’ll  
come across, from instrument levels as low as –50 dBu,  
to operating levels of –10 dBV to +4 dBu, since there  
is –15 to +45 dB of gain (60 dB range) available for  
line inputs via the gain [3] knob. Always make sure  
to perform the level setting procedure on page 5.  
These unbalanced 1/4" jacks are for connecting serial  
effects processors such as compressors, equalizers,  
de-essers, or filters. The insert point is after the gain  
[3] control, but before the channel’s EQ [32], low cut  
[33], fader [25] and mute [30] controls. Insert cables  
must be wired thusly:  
Tip = send (output to effects device)  
Ring = return (input from effects device)  
Sleeve = common ground  
To connect balanced lines to these inputs, use  
a 1⁄4" Tip-Ring-Sleeve (TRS) plug, wired as follows:  
Tip = Positive (+ or hot)  
SEND to processor  
ring  
tip  
(TRS plug)  
tip  
sleeve  
Ring = Negative (– or cold)  
Sleeve = Shield or ground  
This plug connects to one of the  
mixer’s Channel Insert jacks.  
ring  
RETURN from processor  
To connect unbalanced lines to these inputs,  
use a 1⁄4" mono (TS) phone plug, wired as follows:  
Tip = Positive (+ or hot)  
Even though channels 1–8 already have direct out [5]  
jacks , insert jacks can also be used as channel direct  
outputs; post-gain, pre-low cut, and pre-EQ. See the  
connector section on page 29 showing three ways to use  
insert cables.  
Sleeve = Shield or ground  
3. Gain  
3
5. Direct Out  
Yes it’s true, these controls are not 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  
Found only on channels 1–8, these balanced 1/4"  
jacks deliver the signal from the very end of the channel  
path; post-gain [3], post-EQ [32], post-low cut [33],  
that we couldn’t bear to separate them. If you haven’t post-fader [25], and post-mute [30]. They are the key  
already, please read the level-setting procedure on  
page 5.  
player in “split monitoring,” making the 1604VLZ4  
perfect for an 8-track studio.  
Gain 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.  
Split Monitoring  
With split monitoring, you use the first eight  
channels for your sound sources: vocal mics,  
drum mics, keyboard/synth outputs, guitar  
If the signal originates through the XLR jack, there  
will be 0 dB of gain with the knob fully down, ramping  
to 60 dB of gain fully up.  
effects outputs, that sort of thing. From there, the  
channels manipulate the sound, but are not assigned to  
the output section. Instead, they’re patched from the  
channel’s direct out [5] jacks to the corresponding  
multitrack input (direct out 1 to multitrack input 1, 2 to  
2, 3 to 3, etc.). The signals will now be recorded or pass  
directly through the multitrack, depending on each  
track’s record-ready status.  
Through the 1⁄4" input, there is 20 dB of attenuation  
fully down and 40 dB of gain fully up, with a “U” (unity  
gain) mark at 10:00. This 20 dB of attenuation can be  
very handy when you are inserting a very hot signal, or  
when you want to add a lot of EQ gain, or both. Without  
this “virtual pad,” this scenario might lead to channel  
clipping.  
10  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
The point is that you never listen directly to the  
source channels (1–8). You listen to the monitor chan-  
nels (9–16) and they’re listening to the multitrack that  
is listening to the source channels. (Make sure to assign  
the monitor channels 9-16 to the L/R mix, and not the  
source channels 1-8.) The main advantage is that you  
won’t be forced to constantly repatch your multitrack —  
just set it up and forget it. You’ll also know for certain  
that the signals are indeed getting to the multitrack,  
since you’re constantly listening to it.  
multitrack  
machine  
sound sources  
Another method of interfacing a multitrack is called  
inline monitoring, and requires a dedicated mixing  
console. Each of its channels is actually two channels:  
one carrying the mic/line sound source and the other  
carrying the multitrack output.  
1–8  
9–16  
6. Aux Sends  
These 1/4" jacks usually patch to the inputs of  
a parallel effects devices or to the inputs of stage  
monitor amps. For details see Aux Talkon page 23.  
direct  
outputs  
group  
outputs  
Effects: Serial Or Parallel?  
You’ve heard us carelessly toss around the terms  
“serial” and “parallel.” Here’s what we mean by them:  
The outputs of the multitrack are then patched  
to the next eight line [2] inputs on the 1604VLZ4  
(multitrack out 1 to line input 9, 2 to 10, 3 to 11, etc.).  
These channels (9–16) will be assigned to the mixer’s  
output section, delivering the signals to their ultimate  
destination, which may be your mixdown 2-track, your  
control room system, or your headphones.  
“Serial” means that the entire signal leaves the mixer  
[insert (4) send], is routed through the effects device,  
and returns to the mixer [insert return]. Examples:  
compressor/limiters, graphic equalizers.  
Insert  
Send  
Insert  
But let’s not forget that the 1604VLZ4 is a 4-bus  
mixer. These buses lead to the sub outs [8], and are  
designed to accomplish the task of getting channels  
to the multitrack without using the direct outputs.  
Return  
SignalProcessor  
(e.g.,Compressor)  
Processed  
Signal  
Dry Signal  
“Parallel” means that a portion of the signal in the  
mixer is tapped off to the device (aux send), processed  
and returned to the mixer (stereo return) to be mixed  
with the original “dry” signal. This way, multiple  
channels can all make use of the same effects device.  
Examples: reverb, digital delay.  
For example, a channel is assigned to sub out 1.  
Sub out 1’s output is patched to multitrack input 1.  
From there, the multitrack output goes to the mixer’s  
channel 9 line input, as we just discussed. (Hot tip:  
To feed an 8-track deck with 4 sub outputs, simply use  
Y-cords: sub out 1 feeds tracks 1 and 5, 2 feeds 2 and 6,  
3 feeds 3 and 7, and 4 feeds 4 and 8. Tracks in record  
mode will accept the signal, and tracks in safe mode  
will ignore the signal.)  
Aux  
Aux  
Output  
Section  
Send  
Return  
Signal Processor  
(e.g., Reverb)  
Wet Signal  
Mix  
Processed  
Signal  
The advantages: You can assign any channel to any  
track, without repatching. You can assign multiple chan-  
nels to one track and control the overall level of that  
subgroup. You can’t bounce tracks without this feature.  
Stage  
Channel Path  
Dry Signal(s)  
Dry Signal(s)  
Perhaps the best method is to do both: Use the sub  
outs to feed multichannel submixes (like a drum kit)  
to some of the tracks, and the direct out jacks to feed  
single-channel signals (like bass guitar) to the other  
tracks.  
11  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
18  
14  
13 12 11 9  
8
7
15  
16  
19  
7. Stereo Returns  
9. C-R Outs (Control Room Outputs)  
This is where to connect the outputs of parallel  
These 1/4" jacks are usually patched to the inputs of  
a control room amplifier or a headphone distribution  
amplifier. To learn how signals are routed to these  
outputs, see ctl room/phones [43] on page 20.  
effects devices (or extra audio sources). They’ll accept  
just about any pro or semipro effects device on the  
market. To learn how signals are routed from these  
inputs, see stereo return level [51] on page 23.  
10  
10. Phones Out (On Front Panel)  
The 1604VLZ4’s stereo 1/4" phones  
jack will drive any standard  
Mono: If you have an effects device with a mono  
output (one cord), plug that into the left input of  
a stereo return and leave the right input unplugged.  
That way, the signal will be sent to both sides,  
magically appearing in the center as a mono signal.  
headphone to very loud levels.  
To learn how signals are routed to  
these outputs, see ctl room/phones  
[43] on page 20. If you’re wiring your  
own cable for the phones output:  
8. Sub Outs  
These four 1/4" jacks are usually patched to  
the inputs of a multitrack deck, or to secondary  
amplifiers in a complex installation. To learn how  
signals are routed to these outputs, see subgroup  
faders [38], page 19.  
Tip = left channel  
Ring = right channel  
Sleeve = common ground  
WARNING: When we say the headphone  
amp is loud, we’re not kidding. It can cause  
permanent ear damage. Even intermediate  
Double Busing  
How on earth do you get four jacks to feed eight  
tracks? To feed an 8-track deck with only four sub outs,  
simply use four Y-cords:  
levels may be painfully loud with some earphones.  
BE CAREFUL! Always turn the ctl room/phones [43]  
knob all the way down before connecting headphones.  
Keep it down until you’ve put the phones on. Then turn  
it up slowly. Why? “Engineers who fry their ears find  
themselves with short careers.”  
Sub Out 1 feeds tracks 1 and 5  
Sub Out 2 feeds tracks 2 and 6  
Sub Out 3 feeds tracks 3 and 7  
Sub Out 4 feeds tracks 4 and 8  
11. Tape Out  
These unbalanced RCA jacks tap the main mix  
outputs to make simultaneous recording and PA work  
more convenient. Connect these to your 2-track  
recorder’s inputs. To learn how signals are routed  
to these outputs, see main mix [37] fader details  
on page 19.  
Tracks in record mode will accept the signal, and  
tracks in safe mode will ignore the signal. It’s that easy.  
This method is exactly the same as the  
double-busing feature found in other mixers.  
Built-in double-busing is nothing more than  
Y-cords living inside the mixer instead of hanging out  
the back. If we had room for the extra jacks, we would  
have thrown them in, but we don’t, so we didn’t.  
Sonically, there is no difference.  
Mono: If you want to feed a mono signal to your tape  
deck or other device, simply use the 1/4" mono [15]  
output jack.  
Y-cord advice: Do not use the stereo “headphone-to-  
left/right” splitter adapters. Use the type that send the  
same signal to two places; the tip of the source plug  
feeds the tips of both destination plugs.  
12. Tape In  
These unbalanced RCA jacks are designed to work  
with semipro as well as pro recorders. Connect your  
2-track tape recorder’s outputs here, using standard hi-fi  
RCA cables. To learn how signals are routed from these  
inputs, see tape in (level) [40] on page 20.  
12  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Use these jacks for convenient playback of mixes.  
You’ll be able to review a mix, and then rewind and try  
another pass without repatching or disturbing the mixer  
levels. You can also use these jacks with a CD player  
to feed music to a PA system between sets.  
16. Mono Level  
So, Mr. Mono comes running back, screaming about  
the mono mix being so loud that his camcorder is  
melting. Just reach for this knob and turn it down  
a bit. Just the thing for sending mono signals to mic  
inputs like camcorders, telephone interface boxes, even  
answering machines. With the pot all the way up (fully  
clockwise), you’ll have 6 dB of extra gain, with unity  
gain halfway between the one and two o’clock positions.  
WARNING: Pushing tape to main mix [41]  
in the output section can create a feedback  
path between tape input and tape output.  
Make sure your tape deck is not in record, record-pause  
or input monitor mode when you engage this switch,  
or make sure the tape in level knob is fully counter-  
clockwise (off).  
17. Voltage Selector  
Located on the bottom panel, is a voltage selector  
switch.  
13. Main Insert  
These 1/4" jacks are for connecting serial effects such  
as compressors, equalizers, de-essers, or filters. The  
insert point is after the mix amps, but before the main  
mix [37] fader. Insert cables must be wired thusly:  
Tip = send (output to effects device)  
17  
Ring = return (input from effects device)  
Sleeve = common ground  
WARNING: Before you plug the  
AC power cord into the 1604VLZ4,  
you must make sure that this slide  
14. Main Outs  
switch is set to the same voltage as the local  
AC mains supply. Only slide the voltage switch  
with the power cord unplugged.  
These 1/4" jacks are usually patched to the inputs  
of your 2-track mixdown deck (unless you’ve chosen  
to use the tape output [11] RCA jacks), or to the house  
amplifier during live sound sessions. To learn how  
signals are routed to these outputs see main mix [37]  
fader details on page 19. To use these outputs to drive  
balanced inputs, connect 1/4" TRS (Tip-Ring-Sleeve)  
phone plugs like this:  
Use a flat headed screwdriver to slide the switch  
if needed. The switch allows you to use the mixer in  
different countries and voltages, meet interesting  
people from other cultures, and entertain them.  
18. Power Connection  
Tip = Positive (+ or hot)  
Ring = Negative (– or cold)  
Sleeve = Shield or ground  
Just in case you lose the cord provided with the  
1604VLZ4, its power jack accepts a standard 3-prong  
IEC cord like those found on most professional  
recorders, musical instruments, and computers.  
To use these outputs to drive unbalanced inputs,  
connect 1/4" TS (Tip-Sleeve) phone plugs like this:  
Tip = Positive (+ or hot)  
WARNING: Before you plug the AC power  
cord into the 1604VLZ4, you must make sure  
that the voltage selector [17] slide switch is  
set to the same voltage as the local AC mains supply.  
Sleeve = Shield or ground  
15. Mono Out  
It happens to everybody sooner or later: The forces  
that govern your world will demand a monaural  
output from your painstakingly-created stereo  
panorama. The last thing you want to do is start  
twirling all your carefully-placed pan settings to one  
side. What to do? Stick a cord in this 1/4" jack, hand  
the other end to Mr. Mono, and you’re done. He’s got  
his mono mix and you’ve still got your stereo mix.  
The mono output is nothing more than a mix of  
the left and right main mix.  
WARNING: Disconnecting the plug’s ground  
pin can be dangerous. Don’t do it.  
13  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
20 22  
19  
19. Fuse  
24  
The 1604VLZ4 is fused for your (and its own)  
protection. If you suspect a blown fuse, disconnect  
the power cord, pop out the fuse drawer with a small  
flat screwdriver, and replace the fuse with a 1A SLO  
BLO, 5x20mm, available at electronics stores or  
your dealer (or a 500 mA SLO BLO 5x20 mm if  
your 1604VLZ4 is set to 220V-240V).  
If two fuses blow in a row, something is very wrong.  
Please call our toll-free number 1-800-898-3211 from  
within the U.S. (or call the distributor in your country)  
and find out what to do.  
20. Power Switch  
23  
21  
Press the top of this rocker switch inwards to turn  
on the mixer. The power led [21] on the top surface  
of the mixer will glow with happiness, or at least it  
will if you have the mixer plugged in to a suitable  
live AC mains supply.  
22. Phantom Switch  
This switch controls the phantom power supply  
for all the mic [1] inputs, as discussed on page 9.  
When turned on (or off), the phantom power circuitry  
takes a few moments for voltage to ramp up (or down).  
This is perfectly normal. Make sure that you pull down  
the master fader, and headphone/control room volume  
before engaging the phantom switch.  
Press the bottom of this switch to put the mixer into  
standby mode. It will not function, but the circuits are  
still live. To remove AC power, either turn off the AC  
mains supply, or unplug the power cord from the mixer  
and the AC mains supply.  
23. 48V LED  
As a general guide, you should turn the mixer on  
first, before the power amplifier or powered speakers,  
and turn it off last. This will reduce the possibilities  
of any turn-on, or turn-off thumps in the speakers.  
Located right next to the power LED, this is just to let  
you know which way you have the phantom [22] switch  
set. If your dynamic mics work and your condensers  
don’t, chances are this LED is off, so turn it on.  
21. Power LED  
You’ll notice that when you turn the phantom power  
off, the LED stays on for a while. This is a natural phe-  
nomenon — the LED is actually a voltmeter telling you  
that the phantom power takes time to ramp itself down  
to zero volts. So, if you’ve turned phantom power off to  
connect something to the mic inputs, wait until the LED  
stops glowing and then make your connections safely.  
You’ve probably already figured this out, but if the  
power [20] switch is on, this LED (light-emitting  
diode), located in the output section, will light. If the  
switch is off, well, you get the idea. If the power switch  
is on and the LED does not glow, one of three things  
has happened: Somebody tripped over the power cord  
and yanked it from the outlet, your electricity has been  
turned off due to nonpayment, or the fuse has blown.  
24. BNC Lamp Socket  
Located in the top right corner of the output  
section, this 12V socket will drive any standard  
BNC-type lamp (a Littlite® #12G or #12G-HI  
(high-intensity), for instance).  
14  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Channel Strip Description  
The 16 channel strips look alike and  
function identically. So if you learn one,  
you have learned them all. The only  
difference is that the eight on the left  
have direct out [5] jacks and the eight  
on the right don’t. We’ll start at the  
bottom and work our way up.  
26. Assign (1–2, 3–4, L–R)  
Alongside each channel fader are four buttons,  
labeled solo, 1–2, 3–4 and L–R. The latter three are  
collectively referred to as channel assignment switches.  
1, 3 and L are the left sides of these stereo pairs, and  
2, 4 and R are the right sides. Used in conjunction with  
the channel’s pan [31] knob, these switches determine  
the destination of a channel’s signal: With pan set at  
the center detent, the left and right sides receive equal  
signal levels. To feed only one side or the other, just turn  
the pan knob accordingly.  
“U” Like Unity Gain  
VLZ4 mixers have a “U” symbol on  
almost every level control. This “U” stands  
for “unity gain,” meaning no change in  
signal level. Once you have performed  
the level-setting procedure , you can set  
every control at “U” and your signals will  
travel through the mixer at optimal levels.  
What’s more, all the labels on our controls  
are measured in decibels (dB), so you’ll  
know what you’re doing level-wise if you  
choose to change a control’s settings.  
If you’re doing a mixdown to a 2-track, simply engage  
the L–R switch on each channel that you want to hear,  
and they’ll be sent to the main mix. If you want to create  
a subgroup of certain channels, engage either the 1–2  
or 3–4 switches instead of the L–R, and they’ll be sent  
to the appropriate subgroup faders. From there, the  
subgroups can be sent back to the main mix, allowing  
you to use the subgroup faders as a master control for  
those channels.  
If you’re printing new tracks or bouncing existing  
ones, you’ll also use the 1–2 and 3–4 switches, but  
not the L–R switch. Here, you don’t want the subgroups  
sent back into the main mix, but sent out, via the  
sub outs [8] jacks, to your multitrack inputs.  
However, if you’re printing tracks via the direct  
out [5] jacks, all the channel assignment switches  
should be disengaged (up).  
25. Channel Fader  
The fader is almost the last control  
in a channel’s signal path. It’s placed  
after the EQ [32] and mute [30]  
controls (post-EQ /post-mute) and  
before the pan [31]control (pre-pan).  
The “U” mark, about three-quarters of  
the way up, indicates unity gain, meaning  
no increase or decrease of signal level.  
All the way up provides an additional  
10 dB, should you need to boost a section  
of a song. If you find that the overall level  
is too quiet or too loud with a fader near  
unity, you’ll want to confirm the setting  
by performing the level-setting procedure  
on page 5.  
The 1604VLZ4 is what we call a “true 4-bus mixer.”  
Each channel may be assigned or unassigned to any of  
the subgroups without affecting the other subgroups  
or settings within the channel, and each subgroup has  
its own master fader and dedicated output. In fact,  
since there are 4 subgroups and the main L/R mix,  
it’s actually a true 6-bus mixer. We could have named  
it the 1606VLZ4. Darn!  
25  
26  
A Clean Fade  
Faders are not rocket science — they  
operate by dragging a metal pin (the  
wiper) across a carbon-based strip (the  
track). It is possible for airborne crud to  
land on the track. Should that happen, you may hear  
scratchy noises or signal dropouts as the wiper stumbles  
over the crud. Do all you can to keep airborne crud out  
of your profession. Use air-conditioned rooms whenever  
possible, avoid smoking near the mixer, keep food and  
drink away from the mixer, and for pity’s sake, never  
put the mixer in your kitchen! We also recommend  
“exercising” the faders — give them a few full-travel  
excursions once a week or so, and that will help scare  
the crud away. Do not use spray cleaners, rather use  
compressed air, or a vacuum with brush attachment.  
15  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
27. Solo  
29. OL (Mute) LED  
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.  
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.  
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.  
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.  
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  
Here is a quick reference to these LEDs:  
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.  
Name  
Color  
green  
red  
Flickering  
Glowing  
–20 (SOLO)  
OL (MUTE)  
signal present  
channel clipping  
channel soloed  
channel muted  
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!  
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.  
28. –20 (Solo) LED  
An LED that does two completely  
different things! Saves space, recycles  
the planet, but requires some  
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.  
explanation. First, the “–20” part:  
Often referred to as “signal activity,”  
32  
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  
it to glow a bit more steadily.  
31  
Now for the “solo” part. When a  
channel’s solo switch is engaged, this  
LED will glow steadily, without flickering.  
It will also be brighter than it would be  
as a –20 indicator. In conjunction with  
the rude solo light [47], you can find  
a rogue solo switch quickly.  
30  
29  
28  
27  
16  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
+15  
+10  
The low EQ provides up to  
15 dB boost or cut below 80 Hz.  
The circuit is flat (no boost or  
cut) at the center detent posi-  
tion. This frequency represents  
the punch in bass drums, bass  
31. Pan  
+5  
0
This adjusts the amount of channel signal sent to  
the left versus the right outputs. Pan determines the  
fate of the L-R assignment, subgroups 1–2 and 3–4,  
and the solo (in AFL mode). With the pan knob hard  
left, the signal will feed the left main mix, subgroup 1,  
subgroup 3 and left normal (AFL) solo mode (assuming  
their assignment switches are engaged). With the knob  
hard right, signal feeds the right main mix, subgroup 2,  
subgroup 4 and right normal (AFL) solo mode. With pan  
set somewhere in-between left and right, the signal will  
be divided between the left and right buses.  
–5  
–10  
–15  
20Hz  
100Hz  
1kHz  
10kHz 20kHz  
guitar, fat synth patches, and some really serious male  
singers who eat broken glass for breakfast.  
Used in conjunction with the low cut [33] switch,  
you can boost the low EQ without injecting a ton of  
subsonic debris into the mix. We recommend using  
the low cut feature on all channels, except low  
frequency signals, like kick drums and bass guitars.  
Stereo Sources  
The mid EQ , or “midrange,” has a fixed bandwidth of  
1 octave. The mid knob sets the amount of boost or cut,  
up to 15 dB, and is effectively bypassed at the center  
detent. The frequency knob sets the center frequency,  
sweepable from 100 Hz to 8 kHz.  
Your life will be easier if you follow this standard  
convention: When patching stereo sound sources  
to a mixer, always plug the left signal into an “odd”  
channel (1, 3, 5, etc.) and the right signal into the  
adjacent “even” channel (2, 4, 6, etc.). Then pan the  
odd channel hard left and the even channel hard right.  
+15  
+10  
+15  
+10  
+5  
0
+5  
0
Constant Loudness ! ! !  
–5  
–5  
–10  
–15  
–10  
–15  
The 1604VLZ4’s pan controls employ a design  
called “Constant Loudness.” It has nothing to  
do with living next to a freeway. As you turn  
the pan knob from left to right (thereby causing the  
sound to move from the left to the center to the right),  
the sound will appear to remain at the same volume  
(or loudness).  
20Hz  
100Hz  
1kHz  
10kHz 20kHz  
20Hz  
100Hz  
1kHz  
10kHz 20kHz  
Most of the root and lower harmonics that define a  
sound are located in the 100 Hz–8 kHz frequency range,  
and you can create drastic changes with these two  
knobs. Many engineers use mid EQ to cut midrange  
frequencies, not boost them. One popular trick is to set  
the mid fully up, turn the frequency knob until you find  
a point where it sounds just terrible, then back the mid  
down into the cut range, causing those terrible frequen-  
cies to disappear. Sounds silly, but it works. Sometimes.  
If you have a channel panned hard left (or right) and  
reading 0 dB, it must dip down about 4 dB on the left  
(or right) when panned center. To do otherwise, like  
those Brand X mixers, would make the sound appear  
much louder when panned center.  
+15  
The hi EQ provides you up  
to 15 dB boost or cut above  
+10  
32. 3-Band Mid-Sweep EQ  
+5  
12 kHz, and it is also flat at the  
0
The 1604VLZ4 has a 3-band, mid-sweep equalization:  
low shelving at 80 Hz, mid sweep peaking from 100 Hz  
to 8 kHz, and hi shelving at 12 kHz. It’s probably all  
the EQ you’ll ever need! (Shelving means that the  
circuitry boosts or cuts all frequencies past the  
specified frequency. For example, the 1604VLZ4’s  
low EQ boosts bass frequencies below 80 Hz and  
continuing down to the lowest note you never heard.  
Peaking means that certain frequencies form a “hill”  
around the center frequency.)  
detent. Use it to add sizzle to  
cymbals, an overall sense of  
transparency, or an edge to  
keyboards, vocals, guitar and  
bacon frying. Turn it down a little to reduce sibilance  
or to mask tape hiss.  
–5  
–10  
–15  
20Hz  
100Hz  
1kHz  
10kHz 20kHz  
With too much EQ, you can screw things up royally.  
We’ve designed a lot of boost and cut into each equalizer  
circuit because we love you, and know that everyone  
will occasionally need that. But if you max the EQ on  
every channel, you’ll get mix mush. Equalize subtly and  
use the left sides of the knobs (cut), as well as the right  
(boost). If you find yourself repeatedly using full boost  
or cut, consider altering the sound source, such  
as placing a mic differently, trying a different kind of  
mic, changing the strings, or gargling.  
17  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
We recommend going into a stereo reverb in  
mono and returning in stereo. We have found  
that on most “stereo” reverbs, the second  
33. Low Cut  
This switch, often referred to as a high pass filter (all  
depends on how you look at it), cuts bass frequencies  
below 75 Hz at a rate of 18 dB per octave. This ain’t no  
thrown-in dime-store filter — an 18 dB per octave curve  
requires an elaborate circuit. Nothing but the best.  
input just ties up an extra aux send and adds nothing  
to the sound. There are exceptions, so feel free to try it  
both ways. Should you choose to use two aux sends,  
use the “odd” aux (1, 3 or 5) to feed its left input  
and the “even” aux (2, 4 or 6) to feed the right input.  
Remember, if you’re also dealing with a stereo source  
signal, you’ll want to follow the sides — use the odd aux  
We recommend that you use this on every sound  
source except kick drum, bass guitar, or bassy synth  
patches. These aside, there isn’t much down there that  
you want to hear, and filtering it out makes the low stuff on the channel carrying the left side and the even aux  
you do want much more crisp and tasty. Not only that,  
but low cut can help reduce the possibility of feedback  
in live situations, and it helps to conserve amplifier  
power.  
on the channel carrying the right.  
35. Pre  
This switch determines the tap point of aux 1 and 2.  
Generally, “post” sends are used to feed effects devices,  
and “pre” sends are used to feed your stage monitors.  
See the “Pre vs. Post” diagram below. Aux 3 through 6  
are always in post mode.  
With low cut, you can safely boost low EQ. Many  
times, bass shelving EQ can really benefit voices.  
Trouble is, adding low EQ also boosts the subsonic  
debris: Stage rumble, mic handling clunks, wind noise  
and breath pops. Low cut removes all that debris so you  
can boost the low EQ without blowing your subwoofers.  
MUTE  
PAN  
ASSIGN  
LOW  
CUT  
INPUT  
TRIM  
INSERT  
EQ  
FADER  
AUX 1  
Here’s a frequency curve of low EQ combined with  
low cut:  
'PRE' SIGNAL  
'POST' SIGNAL  
PRE SWITCH  
AUX 2  
+15  
+10  
+5  
0
In post mode (switch up), aux 1 and 2 will follow  
–5  
the EQ [32], low cut [33], fader [25], and mute [30]  
settings. If you fade the channel, you fade the send.  
This is a must for effects sends, since you want  
the levels of your “wet” signals to follow the level  
of the “dry.”  
–10  
–15  
20Hz  
100Hz  
1kHz  
10kHz 20kHz  
34. Aux 1, 2, 3, & 4  
These four knobs tap a portion of each  
channel’s signal, mix them together and  
send them to the aux send [6] outputs.  
They are off when turned fully down,  
deliver unity gain at the center detent,  
In pre mode (switch down), aux 1 and 2 follow the  
gain and low cut settings only. EQ, pan, fader, and mute  
settings have no effect on the pre sends. This is the  
preferred method for setting up stage monitor feeds  
— they’ll be controlled independently of the fader and  
34  
35  
and can provide up to 15 dB of gain turned mute moves.  
fully up. Chances are you’ll never need  
this extra gain, but it’s nice to know it’s  
there if you do.  
36. 5/6 Shift  
Don’t let the fact that there’s only four aux knobs  
per channel fool you — the 1604VLZ4 has six aux  
sends [6]. With this 5/6 shift switch up, the knobs  
labeled aux 3 and aux 4 deliver their signals to aux  
send 3 and 4 outputs. With this switch down, the  
signals appear at the aux send 5 and 6 outputs.  
The aux send outputs are then patched  
to parallel effects processor inputs or stage  
monitor amp inputs. Aux sends 1 and 2  
levels are controlled not only by the  
channel’s aux knobs, but also by the  
aux send [49] master knobs.  
36  
We recommend that aux send 3 and 4 be patched into  
your “utility” effects, like a short reverb and slap delay;  
effects you use all the time. Use aux send 5 and 6 for  
“exotic” effects, like harmonizers and multi-tap delays;  
they are not likely to be used as often.  
Aux sends can also be used to  
generate separate mixes for recording  
or “mix-minuses” for broadcast. By using  
aux 1 or 2 in the pre [35] mode, these  
mix levels can be obtained independently  
of a channel’s fader [25] settings.  
33  
18  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Output Section Description  
You’ve just learned about the input channels and how  
the signals get in and out. The signals come in via mic  
[1] and line [2] input jacks, are manipulated by the  
channels, and then sent to the output (master) section.  
Things get a little more complicated, so put on your  
thinking caps, take a deep cleansing breath, take this  
manual, get on a bycycle, ride down to the canal, ponder  
your life and all its unique experiences, then read this  
section.  
37. Main Mix Fader  
This fader controls the levels of signals sent to the  
main out [14] jacks and tape output [11] RCA jacks.  
All channels and stereo returns that are assigned to the  
main mix, not muted and not turned fully down will  
appear at the main outs. Before the main mix gets to  
this fader, the signals pass through the main insert [13].  
The main mix signals are off with the fader fully down,  
the “U” marking is unity gain, and fully up provides  
10 dB additional gain. This additional gain will typically  
never be needed, but once again, it’s nice to know  
it’s there. The fader itself is a stereo version of the  
channel and subgroup faders — same supersmooth  
custom taper, same dead silence when turned fully  
down. This is the fader to pull down at the end of the  
song when you want “The Great Fade-Out.”  
38. Subgroup Faders  
As you might expect, these faders control the levels  
of signals sent to the sub outs [8]. All channels that are  
assigned to subgroups with the assign [26] switches,  
not muted and not turned fully down will appear at the  
sub outs. Unlike the main out [14], the subgroup signals  
do not pass through an insert jack on their way to the  
subgroup faders. That’s no problem — should you want  
to send these signals through a serial effects processor,  
simply patch from the sub outs to the effect’s input,  
and from the effect’s output to whatever the final  
destination is, usually a multitrack recorder.  
The subgroup signal is off when its fader is fully down,  
the “U” marking is unity gain, and fully up provides  
10 dB additional gain. Remember that if you’re  
treating two subgroups as a stereo pair, subgroup  
1 and 2 for example, make sure that both subgroup  
faders “ride” together, to maintain the left/right balance.  
39. Assign To Main Mix  
39  
One popular use of the subgroups is to use them  
as master faders for a group of channels on their way  
to the main mix. Let’s say you’ve got a drum kit hogging  
up seven channels and you’re going to want to fade them  
out at a different rate than the other channels. You don’t  
want to try that with seven hands or seven fingers,  
so just un-assign these channels from L–R, reassign  
them to subgroup 1–2, engage the assign to main mix,  
left on subgroup 1 and the assign to main mix, right  
on subgroup 2. Now you can ride the entire stereo drum  
mix with two faders — 1 and 2.  
38  
37  
If you engage just one assign to main mix switch per  
subgroup (left or right), the signal sent to the main  
mix will be the same level as the sub outs [8]. If you  
want the subgroup to appear in the center of the main  
19  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
mix, engage both the assign to main mix, left and right  
switches. The signal will be sent to both sides, and  
will be attenuated just enough to preserve constant  
loudness, just like the channel pan [31] knobs when  
set in the center.  
41. Tape To LR  
Engaging this switch is just like engaging the L-R  
switch on a channel — the signal, stereo in this case, is  
sent to the main mix. It does not interrupt other signals,  
just adds itself to them. This switch can be very handy  
in a live sound situation when you want to play soothing  
elevator music to an anxious crowd.  
40. Tape In (Level)  
This knob controls the level of the stereo signal com-  
ing from the tape input [12] RCA jacks. Its range is off  
when fully down, unity at the center detent, with 20  
dB additional gain turned fully up, which may come in  
handy if you’ve patched in a device with wimpy output  
levels. After the level is determined, the stereo tape  
signal can be sent to either of two places — the main  
mix or the source [42] matrix.  
WARNING: Engaging tape to main mix can  
create a feedback path between tape input  
[12] and tape output [11]. Make sure your  
tape deck is not in record, record-pause or input  
monitor mode when you engage this switch, or that  
the tape in [40] level knob is turned fully down.  
42. Source  
Typically, the engineer sends the main mix to an  
audience or to a mixdown deck (if recording). But what  
if the engineer needs to hear something other than the  
main mix? With the 1604VLZ4, the engineer has several  
choices of what to listen to. This is one of those tricky  
parts — have a double espresso first.  
Using these switches, you can choose to listen to any  
combination of main mix, subs 1-2, subs 3-4 and tape.  
Selections made here deliver stereo signals to the  
control room, headphones, and meter display. These  
signals are tapped off as follows — post-main mix fader,  
post subgroup faders [38], and post-tape in [40] knob.  
With no switches engaged, there will be no signal  
at these outputs and no meter indication, with two  
exceptions: solo and stereo return 4.  
Regardless of the source matrix selection, engaging  
a solo switch will replace that selection with the solo  
signal, also sent to the control room, headphones, and  
meter display. This is what makes the level-setting  
procedure so easy.  
Now you know how to select the signals you want  
to send to the engineer’s control room and/or phones.  
Once selected, these signals all pass through the same  
level control, aptly named:  
43  
42  
40  
41  
43. CR/Phones  
As you might expect, this knob controls the levels  
of both the stereo control room, and the headphones.  
Make sure that you move it to minimum before selecting  
or adding a new source.  
46  
44  
45  
Whatever your selection, you can also use  
the control room outputs for other applications.  
The sound quality is just as impeccable as the main  
outputs. It can be used as an additional main mix  
output and this one will have its own level control.  
However, should you do this, be aware that if you  
engage a solo [27] switch, that will interrupt the mix:  
47  
20  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Engaging a solo switch will cause this dramatic turn  
of events: Any existing source matrix selections will be  
replaced by the solo signals, appearing in the control  
room, headphones and meter display. The audible solo  
levels are controlled by the solo [46] level knob.  
The solo levels appearing on the meter display  
are not controlled by anything — you wouldn’t want  
that. You want to see the actual channel level on  
the display, regardless of how loud you’re listening.  
45. Level Set LED  
When the mode switch [44] is engaged, it’s in PFL  
mode, the mode you must be in to set levels. Now, when  
you engage any solo switch, this LED will be a “green  
light” to set levels. If you tried to set levels during AFL  
mode, the meter display would be at the mercy of the  
channel fader, and that would be a big problem.  
46. Solo (Level)  
This knob controls the level of the signals coming  
from the solo system. After the solo level is determined,  
the solo signals will proceed to take over the control  
room, headphones, and meter display.  
44. Mode (AFL/PFL)  
The 1604VLZ4’s solo system comes in two flavors:  
AFL (sometimes called SIP, or solo-in-place) and PFL  
(sometimes called PFL, or pre-fader-listen).  
Once again, PFL solo taps the channel signal  
before the fader. If you have a channel’s fader  
set way below “U” (unity gain), PFL solo  
In AFL, the soloed channel’s signal is sent directly  
to the control room, headphones and meter display just  
as it would sound to the channel’s assignment switches:  
post-EQ [32], post-fader [25] and post-pan [31].  
The only difference is that solo works regardless  
of the channel’s assignment positions, and that  
makes it really handy — you can check out a  
channel before you assign it.  
won’t know that and will send a unity gain signal to  
the control room, headphones, and meter display. This  
may result in a startling level boost at these outputs,  
depending on the position of the solo level knob.  
47. Rude Solo Light  
AFL is the preferred mode during mixdown:  
If the channel has some midrange boost at 4.236kHz,  
is panned a smidgen to the left, and its fader is at  
–5.385dB, that’s exactly what you’ll hear if you solo  
during AFL mode. It’s just as if you took the time to  
mute all the other channels.  
This flashing LED (light emitting diode) serves  
two purposes — to remind you that you’re in solo,  
and to let you know that you’re mixing on a 1604VLZ4.  
No other company is so concerned about your level of  
solo awareness. We even force the soloed channel’s –20  
LED to play along, so you can find that rogue switch fast.  
PFL solo is the key player in the all-important  
level-setting procedure . It’ll send the channel’s  
actual internal levels to the meters so you’ll know  
just what’s going on, level-wise. This procedure should  
be performed every time a new sound source is patched  
into a channel’s mic [1] or line [2] input jacks.  
If you work on a mixer that has a solo function with  
no indicator lights, and you happen to forget you’re  
in solo, you can easily be tricked into thinking that  
something is wrong with your mixer. Hence the rude  
solo light. It’s especially handy at about 3:00 in the  
morning, when no sound is coming out of your monitors,  
even though your multitrack is playing back like mad.  
PFL is also the preferred mode for SR (sound  
reinforcement, or live sound), to preview channels  
before they are let into the mix. It won’t give you stereo  
placement, but will give you signal even if the fader  
is turned down.  
Remember, 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.  
21  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
48. Meters  
Meters vs. Reality  
The 1604VLZ4’s peak metering system is made up of  
two columns of twelve LEDs. Deceptively simple,  
considering the multitude of signals that can be  
You may already be an expert at the world of “+4” (+4  
dBu=1.23 V) and “–10” (–10 dBV=0.32 V) operating  
levels. Basically, what makes a mixer one or the other  
monitored by it. If nothing is selected in the source [42] is the relative 0 dB VU (or 0 VU) chosen for the meter  
matrix, and no channels are in solo [27], the meter  
display will just sit there. To put them to work,  
you must make a selection in the source matrix  
(or engage a channel's solo switch).  
display. A “+4” mixer, with a +4 dBu signal pouring out  
the back will actually read 0 VU on its meter display.  
A “–10” mixer, with a –10 dBV signal trickling out, will  
read, you guessed it, 0 VU on its meter display. So when  
is 0 VU actually 0 dBu? Right now!  
Why? You want the meter display to reflect what  
the engineer is listening to, and as we’ve covered, the  
engineer is listening either to the control room output  
At the risk of creating another standard, VLZ4  
compact mixers address the need of both crowds  
or the headphones. The only difference is that while the by calling things as they are: 0 dBu (0.775 V) at the  
listening levels are controlled by the CR/phones [43]  
knob, the meter display reads the source mix before  
that control, giving you the real facts at all times,  
even if you’re not listening at all.  
output shows as 0 VU on the meter display. What could  
be easier? By the way, the most wonderful thing about  
standards is that there are so many to choose from.  
Thanks to the 1604VLZ4’s wide dynamic range,  
When the solo mode [44] switch is set to PFL (down), you can get a good mix with peaks flashing anywhere  
all soloed signals will be sent to the left meter only.  
That, combined with the level set LED [45], are along  
the path of enlightenment known as the level-setting  
procedure (page 5). During AFL mode, the meters will  
behave normally.  
between –20 and +10 dB on the meter display.  
Most amplifiers clip at about +10 dB, and some  
recorders aren’t so forgiving either. For best real-world  
results, try to keep your peaks between “0” and “+7.”  
Please remember: Audio meter displays are just tools  
to help assure you that your levels are “in the ballpark.”  
You don’t have to stare at them (unless you want to).  
If you find that staring at the meters sends you into a  
hypnotic trance, please do not be alarmed. Just cut my  
lawn and polish my car every Tuesday.  
43  
48  
42  
45  
44  
22  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
These knobs go from off (turned fully down), to unity  
gain at the center detent, with 10 dB of extra gain  
(turned fully up). As with some other level controls, you  
may never need the additional gain, but if you ever do,  
you’ll be glad you bought a 1604VLZ4.  
This is usually the knob you turn up when the lead  
singer glares at you, points at his stage monitor, and  
sticks his thumb in the air. (It would follow suit that if  
the singer stuck his thumb down, you’d turn the knob  
down, but that never happens.)  
52  
49  
50  
51  
51  
50. Aux Sends Solo  
Once again, in live sound situations aux send 1 and  
2 are likely to feed your stage monitors. You’ll want to  
check the mix you’re sending them, and that’s what  
these two buttons are for. (Aux 3 through aux 6 have no  
such switch.) Beside each switch is a green LED that,  
just like the channel’s –20 LED [28], helps you find the  
rogue solo switch.  
54  
56  
53  
55  
The only thing different about aux sends solo is that  
it’s not really PFL (pre-fader listen), and it’s not really  
SIP (solo-in-place), it’s actually AFL (after-fader  
listen). During AFL [44] mode , you’ll get aux send 1’s  
solo signal, post-aux sends [49] master level, in the left  
side of the control room outputs, phones output and  
meter display, and aux send 2 on the right side. (If you  
ever use aux 1 and 2 to create a stereo monitor mix,  
you’ll understand why.) In PFL mode, you’ll get the  
signal dead-center, but still post-aux sends master level.  
Aux Talk  
Sends are outputs, returns are inputs. Each channel's  
aux [34] knobs tap the signal off the channel and send  
it to the aux send [6] outputs. Aux 1 and 2 are sent to  
the aux sends 1 and 2 [49] master knobs before the aux  
send outputs; aux 3 through 6 are sent directly.  
51. Stereo Returns (Level)  
These outputs can be fed to the inputs of a reverb or  
other device. From there, the outputs of the external  
device are fed back to the mixer’s stereo return [7]  
inputs. Then these signals are sent through the stereo  
return [51] level controls, and finally delivered to the  
main mix.  
These four controls set the overall level of effects  
received from the stereo return [7] input jacks. These  
controls are designed to handle a wide range of signal  
levels — each knob goes from off, to unity gain at the  
detent, to 20 dB gain fully clockwise, to compensate for  
low-level effects. Signals passing through these level  
controls will proceed directly to the main mix fader  
[37], with exceptions that we’ll discuss in a moment.  
So, the original “dry” signals come from the channels  
to the main mix, and the affected “wet” signals come  
from the stereo returns to the main mix, and once mixed  
together, the dry and wet signals combine to create a  
glorious sound. Armed with this knowledge, let’s visit  
the Auxiliary World:  
Typically, these knobs can just live at the center  
detent, and the effects device’s output control should  
be set at whatever they call unity gain (check their  
manual). If that turns out to be too loud or too quiet,  
adjust the effects device’s outputs, not the mixer.  
That way, the mixer’s knobs are easy to relocate  
at the center detent.  
49. Aux Sends (Master)  
These knobs provide overall level control of aux sends  
1 and 2, just before they’re delivered to their aux send  
[6] outputs. This is perfect for controlling the level  
of stage monitors, since you’ll be using aux 1 and 2 for  
this, with their pre [35] switches engaged. Aux sends 3  
through 6 have no such control — they’ll just send their  
mixes directly to their respective aux send outputs at  
unity gain.  
23  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
53. Main Mix To Subs (Stereo Return 3)  
With this switch up, stereo return 3 behaves like all  
the others — it delivers a stereo signal, regulated by  
its level knob, to the main mix. When you engage this  
switch, the signals are removed from the main mix  
buses and sent to the 1-2/3-4 switch, which diverts the  
signal once more. We’re not finished. Please read on.  
54. 1–2/3–4 (Stereo Return 3)  
52  
49  
50  
51  
51  
If the main mix to subs [53] switch is disengaged,  
this switch does absolutely nothing. Let’s now assume  
it’s engaged. Stereo return 3’s stereo signal will not be  
sent to the main mix, but to subgroup faders 1 and 2  
(this switch up) or subgroup faders 3 and 4 (this switch  
down).  
54  
56  
53  
55  
Let’s say you’ve made a stereo drum submix on  
subgroup faders 1 and 2, so you can ride those two  
faders instead of the seven channels that the drums  
came from. Subgroup fader 1 has its assign to main  
mix [39], left button engaged and subgroup fader 2  
has its assign to main mix, right button engaged,  
blending the drum submix back into the main mix.  
The drum channels are also sending signals to your  
reverb via the aux sends [6], and the reverb outputs  
are patched into stereo return 3 [7]. So far so good.  
52. To Aux 1 and To Aux 2  
Even though you could send stereo return 3 directly  
to the main mix (main mix to subs [53] switch up),  
you don’t want to. Instead, engage the main mix to subs  
switch and make sure the 1–2/3–4 switch is up. Now the  
reverb return will be blended into the drum submix, and  
as you ride those two faders, the reverb level will follow.  
If you want to add reverb or delay to the stage  
monitor mixes, these are the knobs for you.  
Operating independently of their respectively  
numbered stereo returns [51] level controls, these  
knobs are exactly the same as the channel strip  
aux 1 [34] and aux 2 knobs.  
Why do we want that? Because if you had just sent  
the reverb directly to the main mix (main mix to subs  
switch up) and you did a drum fade-out using subgroup  
faders 1 and 2, the “dry” signals would fade out, but the  
“wet” signals would keep on singing. All you would hear  
is the drum reverb (the “wet”), and none of the original  
drum signals (the “dry”). That’s because the reverb is  
being fed by the channel’s aux sends, and they have no  
idea that you’ve pulled down the subgroup faders. That’s  
why we threw in these switches, phew!  
These two knobs feed stereo return signals to their  
respective aux send [6] outputs:  
To aux send 1 feeds stereo return 1 to aux send 1  
master, and:  
To aux send 2 feeds stereo return 2 to aux send 2  
master.  
They are off when turned fully down, deliver unity  
gain at the center detent, and can provide up to 15 dB  
of gain turned fully up. Stereo return 3 and 4 have no  
such knobs.  
24  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
55. CR/PH Only (Stereo Return 4)  
Once again, the default for all the stereo returns is to  
feed them directly into the main mix. You’ve just learned  
about the optional exceptions involving stereo return 3.  
Stereo return 4 also has an optional exception: By  
engaging this switch, you will remove stereo return 4’s  
stereo signal from the main mix and send it directly to  
the CR/phones source [42] matrix. It matters not if any  
of the source matrix switches are assigned, but it will be  
interrupted, as usual, if a solo [27] switch is engaged.  
Let’s pretend you’re doing a live mix to a 2-track deck,  
a house PA, or both, and you want to play along to a  
click track. You could run the click track directly into  
the main mix, but you don’t want the mixdown deck  
and/or audience to hear it. By gum, this is the switch  
for you. Similarly, it can be used for voice-over tracks,  
narration, anything you want heard by the engineer and  
players but not by the audience and mixdown deck.  
56. Returns Solo and LED  
This switch operates just like the channel solo [27]  
switches — engaging it sends signals to the control  
room, headphones, and meter display, and interrupts  
whatever happened to be there before you soloed.  
It follows the mode [44] switch setting as well.  
The only difference is that when you engage this  
returns solo switch, it sends all four stereo returns  
signals to the solo circuit.  
Assume you want to solo the snare drum. Hit that  
channel’s solo switch, and you get the “dry” (no effects)  
snare only. That helps, but you want to hear it with the  
reverb you have patched into a stereo return. Leaving  
that channel’s solo switch engaged, also engage the  
returns solo switch, and now you’ll get the dry snare  
and its reverb.  
Since it is a global feature, you’ll also get the signals  
from all the other stereo returns, so there may be some  
sounds that you didn’t want to hear. If they offend your  
sensibilities, simply turn down the levels of the stereo  
returns you don’t want to hear, or mute the channels  
feeding the unwanted signal to the effects device you  
do want to hear.  
Congratulations! You’ve just read about all the  
features of your 1604VLZ4. You’re probably ready for  
a cold one. Go ahead. The rest of the manual can wait.  
25  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Appendix A: Service Information  
Warranty Service  
Repair  
If you think your 1604VLZ4 has a problem, please  
check out the following troubleshooting tips and do  
your best to confirm the problem. Visit the Support  
you will find lots of useful information such as FAQs  
and other documentation. You may find the answer  
to the problem without having to send your mixer away.  
For warranty service, refer to the warranty  
information on page 35.  
Non-warranty service is available at a factory-  
authorized service center. To locate the nearest  
Tech Support” and select “Locate a Service Center  
or Distributor” [3]. Service for a 1604VLZ4 living  
outside the United States may be obtained through  
local dealers or distributors.  
Troubleshooting  
If you do not have access to our website, you can  
call our Tech Support department at 1-800-898-3211,  
Monday-Friday, normal business hours, Pacific Time,  
to explain the problem. Tech Support will tell you where  
the nearest factory-authorized service center is located  
in your area.  
Bad Channel  
Are the channels assigned to the correct mix  
(1-2, 3-4, L-R )?  
Is the fader up?  
Try unplugging any insert devices from the  
insert jacks.  
Try the same source signal in another channel,  
set up exactly like the suspect channel.  
Bad Output  
Is the level control (if any) turned up?  
If you’re listening to the CR outs or phones  
outputs, has a source selection been made?  
If it’s one of the main outs, try unplugging its  
companion. For example, if it’s the 1/4" left  
main out, unplug the RCA output. If the  
problem goes away, it’s not the mixer.  
Appendix B: Connections  
If it’s a stereo pair, try switching them around.  
For example, if a left output is presumed dead,  
switch the left and right cords, at the mixer  
end. If the problem stays on the left, it’s not the  
mixer.  
Balanced XLR Input Connector  
The 1604VLZ4 mixer has 16 female XLR inputs.  
Be sure the cables are wired per AES (Audio  
Engineering Society) standards:  
Unplug everthing from the main inserts.  
Balanced XLR Input Connector  
Noise  
Pin 1 – Shield (Ground)  
Pin 2 – Positive (+ or hot)  
Pin 3 – Negative (– or cold)  
Turn the channel faders and stereo return  
knobs down, one by one. If the sound  
disappears, it’s either that channel or  
whatever is plugged into it, so unplug  
whatever that is. If the noise disappears,  
it’s from your whatever.  
2
SHIELD  
HOT  
1
3
COLD  
SHIELD  
COLD  
HOT  
1
Power  
3
2
Unplug the power cord and check the fuse.  
Balanced XLR Input Connector  
26  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
accept 1-plug-type stereo microphones. They  
must be separated into a left cord and a right  
cord, which are plugged into the two mic  
preamps.  
Balanced XLR Output Connector  
The male XLR connectors provide a balanced line-  
level signal that represents the end of the mixer, where  
the fully mixed stereo signal enters the real world.  
Connect these to the left and right line-level inputs  
of powered speakers or to the left and right line-level  
inputs of an amplifier (with speakers already attached).  
Be sure the cables are wired per AES (Audio  
You can cook up your own adapter for a stereo  
microphone. “Y” two cables out of a female 1⁄4"  
TRS jack to two male XLR plugs, one for the  
right signal and one for the left.  
Unbalanced send/return circuits. When wired  
as a send/return “Y” connector, a 1⁄4" TRS jack  
or plug is connected tip to signal send (output  
from mixer), ring to signal return (input back  
into mixer), and sleeve to ground (earth).  
Engineering Society) standards:  
Balanced XLR Output Connector  
Pin 1 – Shield (Ground)  
Pin 2 – Positive (+ or hot)  
Pin 3 – Negative (– or cold)  
Unbalanced 1/4" TS Connector  
SHIELD  
1
TS stands for Tip-Sleeve, the two connections  
available on a mono 1⁄4" cable. This allows for a direct  
conection to the channel input jacks. Be sure the cables  
are wired per AES (Audio Engineering Society)  
standards:  
3
COLD  
3
2
HOT  
SHIELD  
COLD  
HOT  
1
2
Unbalanced 1/4" TS Connector  
Balanced XLR Output Connector  
Sleeve – Shield (Ground)  
Tip – Positive (+ or hot)  
Balanced 1/4" TRS Connector  
SLEEVE  
SLEEVE  
TIP  
TRS stands for Tip-Ring-Sleeve, the three connections  
available on a stereo 1/4" cable. This allows for a direct  
connection to the channel input jacks. Be sure the  
cables are wired per AES (Audio Engineering Society)  
standards:  
TIP  
TIP  
SLEEVE  
Unbalanced 1/4" TS Connector  
TS jacks and plugs are used in many different  
applications, always unbalanced. The tip is connected  
to the audio signal and the sleeve to ground (earth).  
Some examples:  
Balanced 1/4" TRS Connector  
Sleeve – Shield (Ground)  
Tip – Positive (+ or hot)  
Ring – Negative (– or cold)  
Unbalanced microphones  
RING SLEEVE  
SLEEVE RINGTIP  
Electric guitars and electronic instruments  
Unbalanced line-level connections  
TIP  
RING  
TIP  
Switched 1/4" Phone Jacks  
SLEEVE  
Switches can be incorporated into 1⁄4" phone jacks,  
which are activated by inserting the plug. These  
switches may open an insert loop in a circuit, change  
the input routing of the signal or serve other functions.  
The 1604VLZ4 uses switches in the channel insert and  
bus insert jacks, input jacks and stereo returns. It also  
uses these switches to ground the line-level inputs when  
nothing is plugged into them.  
Balanced 1/4" TRS Connector  
TRS jacks and plugs are used in several different  
applications:  
Balanced mono circuits. When wired as a  
balanced connector, a 1⁄4" TRS jack or plug  
is connected tip to signal high (hot), ring to  
signal low (cold), and sleeve to ground (earth).  
In most cases, the plug must be inserted fully to  
activate the switch. The 1604VLZ4 takes advantage of  
this in some circuits, specifying circumstances where  
you are to insert the plug only partially. See “Special  
Connections”, on the next page.  
Stereo Headphones, and rarely, stereo  
microphones and stereo line connections.  
When wired for stereo, a 1⁄4" TRS jack or plug  
is connected tip to left, ring to right and sleeve  
to ground (earth). VLZ4 mixers do not directly  
27  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Unbalanced RCA Connector  
TRS Send/Receive Insert Jacks  
RCA-type plugs (also known as phono plugs)  
and jacks are often used in home stereo and video  
equipment and in many other applications. RCA plugs  
are unbalanced. Connect the signal to the center post  
and the ground (earth) or shield to the surrounding  
“basket.” Be sure the cables are wired per AES (Audio  
Engineering Society) standards:  
Single-jack inserts are three-conductor, TRS-type 1⁄4"  
phone. They are unbalanced, but have both the mixer  
output (send) and the mixer input (return) signals in  
one connector. See the illsutration below.  
The sleeve is the common ground (earth) for both  
signals. The send from the mixer to the external unit is  
carried on the tip, and the return from the unit to the  
mixer is on the ring.  
Unbalanced RCA Connector  
Sleeve – Shield (Ground)  
Tip – Positive (+ or hot)  
SEND to processor  
ring  
tip  
(TRS plug)  
tip  
sleeve  
SLEEVE  
TIP  
SLEEVE  
TIP  
This plug connects to one of the  
mixer’s Channel Insert jacks.  
ring  
RETURN from processor  
Unbalanced 1/4" Insert Connectors  
Unbalanced RCA Connector  
Special Connections  
Unbalancing a Line  
The balanced-to-unbalanced connection has been  
anticipated in the wiring of 1604VLZ4 jacks. A 1⁄4" TS  
plug inserted into a 1⁄4" TRS balanced input, for  
example, will automatically unbalance the input and  
make all the right connections. Conversely, a 1⁄4"  
TRS plug inserted into a 1⁄4" unbalanced input will  
automatically tie the ring (low or cold) to ground  
(earth).  
In most studio, stage and sound reinforcement situ-  
ations, there is a combination of balanced and unbal-  
anced inputs and outputs on the various pieces of  
equipment. This usually will not be a problem in making  
connections.  
When connecting a balanced output to an  
unbalanced input, be sure the signal high (hot)  
connections are wired to each other, and that  
the balanced signal low (cold) goes to the  
ground (earth) connection at the unbalanced  
input. In most cases, the balanced ground  
(earth) will also be connected to the ground  
(earth) at the unbalanced input. If there are  
ground-loop problems, this connection may be  
left disconnected at the balanced end.  
Using the Send Only on an Insert Jack  
If you insert a TS (mono) 1⁄4" plug only partially (to  
the first click) into a VLZ4 insert jack, the plug will not  
activate the jack switch and will not open the insert  
loop in the circuit (thereby allowing the channel signal  
to continue on its merry way through the mixer).  
When connecting an unbalanced output to a  
balanced input, be sure that the signal high  
(hot) connections are wired to each other. The  
unbalanced ground (earth) connection should  
be wired to the low (cold) and the ground  
(earth) connections of the balanced input. If  
there are ground-loop problems, try connecting  
the unbalanced ground (earth) connection only  
to the input low (cold) connection, and leaving  
the input ground (earth) connection discon-  
nected.  
This allows you to tap out the channel or bus signal  
without interrupting normal operation.  
If you push the 1⁄4" TS plug in to the second click,  
you will open the jack switch and create a direct out,  
which does interrupt the signal in that channel. See the  
illustration on the next page.  
In some cases, you will have to make up special  
adapters to interconnect your equipment. For  
example, you may need a balanced XLR female  
connected to an unbalanced 1⁄4" TS phone  
plug.  
28  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
NOTE: Do not overload or short-circuit the signal you  
are tapping from the mixer. That will affect the internal  
signal.  
VLZ4 Stereo Inputs and Returns:  
Mono, Stereo, Whatever  
Stereo line inputs and stereo returns are a fine  
example of our philosophy (which we just made up)  
of Maximum Flexibility with Minimum Headache.  
The inputs and returns will automatically be mono  
or stereo, depending upon how you use the jacks.  
Here’s how it works:  
MONO PLUG  
Channel Insert jack  
Direct out with no signal interruption to master.  
Insert only to first click.  
A mono signal should be patched into the input  
or return jack labeled left (mono). The signal will  
be routed to both the left and right sides of the return  
circuit, and will show up in the center of the stereo pair  
of buses it’s assigned to, or it can be panned with the  
pan [26] control.  
MONO PLUG  
Channel Insert jack  
Direct out with signal interruption to master.  
Insert all the way in to the second click.  
A stereo signal, having two plugs, should be patched  
into the left (mono) and the right input or return jacks.  
A jack switch in the right jack will disable the mono  
function, and the signals will show up in stereo.  
STEREO  
PLUG  
Channel Insert jack  
For use as an effects loop.  
(Tip = Send TO effect, Ring = Return FROM effect).  
A mono signal connected to the right jack will show  
up in the right bus only. You probably will only want to  
use this sophisticated effect for special occasions.  
Using the Send Only on an Insert Jack  
Mults and “Y”s  
A mult or “Y” connector allows you to route one output  
to two or more inputs by simply providing parallel  
wiring connections. You can make “Y”s and mults for  
the outputs of both unbalanced and balanced circuits.  
Remember: Only mult or “Y” one output into  
several inputs. If you need to combine several  
outputs into one input, you must use a mixer,  
not a mult or a “Y.”  
Y-cord splitter cable  
RING (IN)  
RING  
TIP  
(RETURN) (SEND)  
RING (RETURN)  
TIP (OUT)  
TO MIXER  
CHANNEL INSERT  
FROM  
PROCESSOR  
OUTPUT  
TO  
PROCESSOR  
INPUT  
TIP (SEND)  
Y-cord insert cable  
29  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Appendix C: Technical Information  
Specifications  
Main Mix Noise  
Impedances  
Mic in:  
2.5 k  
(20 Hz–20 kHz bandwidth, 1/4" Main out, channel gains @  
unity gain, channel EQs flat, all channels assigned to Main Mix,  
odd channels panned left, even channels panned right.)  
Channel Insert return:  
All other inputs:  
Tape out:  
2.5 k  
10 k or greater  
Main Mix fader unity, channel faders down:  
(92 dB Signal to Noise Ratio, ref +4 dBu)  
–88.5 dBu  
1.1 k  
120  
All other outputs:  
Main Mix fader unity, channel faders @ unity: –82.5 dBu  
EQ  
Total Harmonic Distortion (THD)  
High Shelving  
Mid Peaking  
Low Shelving  
Low Cut Filter  
15 dB @ 12 kHz  
(1 kHz 35 dB gain, 20 Hz–20 kHz bandwidth)  
15 dB sweep 100 Hz–8 kHz  
15 dB @ 80 Hz  
Mic in to insert send:  
Mic in to Main Out:  
<0.0007%  
<0.005%  
18 dB/octave, –3 dB @ 75 Hz  
Attenuation (Crosstalk)  
(1 kHz relative to 0 dBu, 20 Hz–20 kHz bandwidth,  
Line in, 1⁄4" Main Out, Gain @ unity.)  
Power Consumption  
50 watts  
Channel Mute switch engaged:  
Channel Gain knob down:  
–84 dBu  
–84 dBu  
Fuse Ratings  
100–120 VAC  
220–240 VAC  
1A Slo Blo, 5 x 20 mm  
0.5A Slo Blo, 5 x 20 mm  
Frequency Response  
Mic Input to Main Output (Gain @Unity)  
Dimensions (H x W x D) in Normal Pod Position  
+0, –1 dB, 20 Hz to 50 kHz  
17.0" x 17.3" x 5.1" (433 mm x 440 mm x 129 mm)  
+0, –3 dB, <10 Hz to >100 kHz  
Weight  
Equivalent Input Noise (EIN)  
20.0 lb (9.1 kg)  
(Mic in to Insert Send out, max gain.)  
150 termination:  
–128.5 dBu  
Since we are always striving to improve our products by  
incorporating new and improved materials, components, and  
manufacturing methods, we reserve the right to change these  
specifications at any time without notice.  
Common Mode Rejection Ratio (CMRR)  
(Mic in to Insert Send out, max gain.)  
The “Running Man” figure is a registered trademark of  
LOUD Technologies Inc. All other brand names mentioned  
are trademarks or registered trademarks of their respective  
holders, and are hereby acknowledged.  
1 kHz:  
better than –70 dB  
Maximum Levels  
Mic in:  
+22 dBu  
+22 dBu  
+28 dBu  
+22 dBu  
The technical writer responsible for this manual tends to fade  
in and out of various different realities, depending on how  
many cups of tea he has had. Please check our website for any  
All other inputs:  
Main Mix TRS out:  
All other outputs:  
©2013 LOUD Technologies Inc. All Rights Reserved.  
30  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
Dimensions  
19.0 in / 483 mm  
[with rack ears fitted]  
5.6 in / 141 mm  
[with rack ears fitted  
in upper position]  
5.1 in / 129 mm  
17.3 in / 440 mm  
WEIGHT  
20 lb  
9.1 kg  
9.4 in / 238 mm  
[with rack ears fitted in upper position]  
Pod in normal position  
8.7 in / 222 mm  
6.3 in / 160 mm  
[with rack ears fitted in upper position]  
Pod in back position  
5.7 in / 144 mm  
Pod in front (with optional RotoPod)  
31  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
Track Sheet  
Session:  
Date:  
Notes:  
32  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
33  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
BlockDiagram  
CR/PHN R  
CR/PHN L  
LOGIC  
PFL  
SIP R  
SIP L  
AUX 6  
AUX 5  
AUX 4  
AUX 3  
AUX 2  
AUX 1  
SUB 4  
SUB 3  
SUB 2  
SUB 1  
MAIN R  
MAIN L  
34  
1604VLZ4  
Download from Www.Somanuals.com. All Manuals Search And Download.  
1604VLZ4 Limited Warranty  
Please keep your sales receipt in a safe place.  
This Limited Product Warranty (“Product Warranty”) is provided by LOUD Technologies Inc. (“LOUD”)  
and is applicable to products purchased in the United States or Canada through a LOUD-authorized  
reseller or dealer. The Product Warranty will not extend to anyone other than the original purchaser of  
the product (hereinafter, “Customer,” “you” or “your”).  
For products purchased outside the U.S. or Canada, please visit www.720trees.com to find contact  
information for your local distributor, and information on any warranty coverage provided by the  
distributor in your local market.  
LOUD warrants to Customer that the product will be free from defects in materials and workmanship  
under normal use during the Warranty Period. If the product fails to conform to the warranty then LOUD  
or its authorized service representative will at its option, either repair or replace any such nonconforming  
product, provided that Customer gives notice of the noncompliance within the Warranty Period to the  
Company at: www.720trees.com or by calling LOUD technical support at 1.800.898.3211 (toll-free in  
the U.S. and Canada) during normal business hours Pacific Time, excluding weekends or LOUD holidays.  
Please retain the original dated sales receipt as evidence of the date of purchase. You will need it to obtain  
any warranty service.  
For full terms and conditions, as well as the specific duration of the Warranty for this product, please visit  
www.720trees.com.  
The Product Warranty, together with your invoice or receipt, and the terms and conditions located at  
www.720trees.com constitutes the entire agreement, and supersedes any and all prior agreements  
between LOUD and Customer related to the subject matter hereof. No amendment, modification or  
waiver of any of the provisions of this Product Warranty will be valid unless set forth in a written  
instrument signed by the party to be bound thereby.  
35  
Owner’s Manual  
Download from Www.Somanuals.com. All Manuals Search And Download.  
 
16220 Wood-Red Road NE  
Woodinville, WA 98072 • USA  
Phone: 425.487.4333  
Toll-free: 800.898.3211  
Fax: 425.487.4337  
Download from Www.Somanuals.com. All Manuals Search And Download.  

Lenovo Computer Accessories K5923 User Manual
Lindy Switch 32343 User Manual
Linksys Network Card WAP54A User Manual
Lochinvar Boiler WB50 thru 210 User Manual
Makita Nail Gun AF501 User Manual
Marmitek MP3 Docking Station iParty User Manual
MB QUART Lawn Mower SCR User Manual
McCulloch Tiller 532 43 21 09 User Manual
Melissa Fan 271 006 User Manual
Mercury Marine Marine Instruments 90 899883399 User Manual