1604-VLZ3 16-Channel Mic/Line Mixer Owner`s Manual

1604-VLZ3 16-Channel Mic/Line Mixer Owner`s Manual

Patchbay Description


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: a tape recorder, PA system, etc. A few of the features described in this section are on top of the mixer, but most are out back on this “pod.”

See Appendix B (page 27) for further details and some rather lovely drawings of the connectors you can use with the 1604-VLZ3.


Concerned about levels, balancing, impedances, polarity, or other interface goblins?

Don’t be. On your 1604-VLZ3, you can patch anything almost anywhere, 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).

• 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 every time you patch in a new sound source. So stop worrying and start mixing!


We use phantom-powered, balanced microphone inputs just like the big studio mega-consoles, for exactly the same reason: This kind of circuit is excellent at rejecting hum and noise. You can plug in almost any kind of mic that has a standard XLR-type male mic connector.

Professional ribbon, dynamic, and condenser mics will all sound excellent through these inputs. The

1604-VLZ3’s mic inputs will handle any kind of mic level you can toss at them, without overloading. Be sure to perform the Level-Setting Procedure on page 3.

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.


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.

The 1604-VLZ3’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.)

Never plug single-ended (unbalanced) micro phones, or ribbon mics into the MIC input jacks if phantom power is on.

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.

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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 3.


These unbalanced 1/4" jacks are for connecting serial

effects processors such as compressors, equalizers, de-essers, or fi lters. 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 ring sleeve

(TRS plug)

SEND to processor


To connect balanced lines to these inputs, use a 1⁄4"

Tip-Ring-Sleeve (TRS) plug, the type found on stereo headphones:

This plug connects to one of the mixer’s Channel Insert jacks.

RETURN from processor


To connect unbalanced lines to these inputs, use a

1⁄4" mono (TS) phone plug or instrument cable:


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 [1] and LINE [2] input jacks that we couldn’t bear to separate them. Here’s why:

Every time you plug something into a MIC or

LINE input jack, you should perform the Level-

Setting Procedure, and that procedure is basically “how to use the GAIN knob.”

Tip = send (output to effects device)

Ring = return (input from effects device)

Sleeve = common ground

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 (fi gure F) showing three ways to use insert cables.


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], post-FADER [25], and post-MUTE [30]. They are the key player in “split monitoring,” making the 1604-VLZ3 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.

Through the XLR jack (MIC), there will be 0 dB of gain with the knob fully down, ramping to 60 dB of gain fully up.

Through the 1/4" input (LINE), there is 15 dB of attenuation fully down and 45 dB of gain fully up, with a

“U” (unity gain) mark at 10:00.

This 15 dB of attenuation can be very handy when you are inserting a signal that is very hot, or you want to add a lot of EQ gain, or both. Without this “virtual pad,” this scenario might lead to channel clipping.


With split monitoring, you use the fi rst eight channels for your sound sources: vocal mics, drum mics, keyboard/synth outputs, guitar 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.


multitrack machine sound sources

1–8 9–16 direct outputs group outputs to some of the tracks, and the DIRECT OUT jacks to feed single-channel signals (like bass guitar) to the other tracks.

The point is that you never listen directly to the source channels (1–8). You listen to the monitor channels (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.

Another method of interfacing a multitrack is called inline monitoring, and requires a dedicated mixing console, like the Mackie 8•Bus. Each of its channels is actually two channels: one carrying the mic/line sound source and the other carrying the multitrack output.

The outputs of the multitrack are then patched to the next eight LINE [2] inputs on the 1604-VLZ3 (multitrack out 1 to LINE input 9, 2 to 10, 3 to 11, etc.). Aha!

That’s why it says “TRACK 1” next to channel 9’s fader,

“TRACK 2” next to channel 10, and so forth. 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.


These 1 /


" jacks usually patch to the inputs of your parallel effects devices or to the inputs of your stage monitor amps. For details see "Aux Talk" on page 23.


You’ve heard us carelessly toss around the terms “serial” and “parallel.” Here’s what we mean by them:

“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, limiter, graphic equalizer. Line-level sources can also be patched through a serial effects device before or after the mixer.

But let’s not forget that the 1604-VLZ3 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.

Dry Signal



Signal Processor

(e.g., Compressor)





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.)

“Parallel” means that a portion of the signal in the mixer is tapped off to the device (AUX SEND [6]), processed, and returned to the mixer (STEREO RETURN

[7]) 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.







Signal Processor

(e.g., Reverb)

Wet Signal

The advantages: You can assign any channel to any track, without repatching. You can assign multiple channels to one track and control the overall level of that subgroup. You can’t bounce tracks without this feature.

Dry Signal(s)

Channel Path

Dry Signal(s)





Perhaps the best method is to do both: Use the SUB

OUTS to feed multichannel submixes (like a drum kit)

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13 12 11 9 8




This is where you connect the outputs of your parallel 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.

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:


These 1/4" jacks are usually patched to the inputs of your control room amplifi er or a headphone distribution amplifi er. To learn how signals are routed to these outputs, see CTL ROOM/PHONES [43] on page 20.

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.


These four 1/4" jacks are usually patched to the inputs of a multitrack deck, or to secondary amplifi ers in a complex installation. To learn how signals are routed to these outputs, see SUBGROUP FADERS [38], page 19.

10. PHONES OUTPUT (on front panel)

The 1604-VLZ3’s stereo 1/4" phones jack will drive any standard headphone to very loud levels. Walkperson-type phones can also be used with an appropriate adapter. 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:

• 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

Tracks in record mode will accept the signal, and tracks in safe mode will ignore the signal. It’s that easy.

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 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 fi nd themselves with short careers.”


This method is exactly the same as the double- busing feature found in other mixers.

Built-in double-busing is nothing more than Ycords 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.

Y-cord advice: Do not use the stereo “headphone-toleft/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.


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.

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.




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.


[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 counterclockwise (off).

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.

Use these jacks for convenient playback of your 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 portable tape or CD player to feed music to a PA system between sets.


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.


Located on the bottom panel, is a voltage selector switch.


These 1/4" jacks are for connecting serial effects such as compressors, equalizers, de-essers, or fi lters. 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)

Ring = return (input from effects device)

Sleeve = common ground (connect shield to all three sleeves)

WARNING: Before you plug the AC power cord into the 1604-VLZ3, you must make sure that this slide switch is set to the same voltage as your 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 amplifi er 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 fl at 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.


Just in case you lose the cord provided with the 1604-

VLZ3, its power jack accepts a standard 3-prong IEC cord like those found on most professional recorders, musical instruments, and computers.

Tip = + (hot)

Ring = – (cold)

Sleeve = ground

To use these outputs to drive unbalanced inputs, connect 1/4" TS (Tip-Sleeve) phone plugs like this:

Tip = signal

Sleeve = ground

WARNING: Before you plug the AC power cord into the 1604-VLZ3, you must make sure that the VOLTAGE SELECTOR [17] slide switch is set to the same voltage as your local AC mains supply.

WARNING: Disconnecting the plug’s ground pin can be dangerous. Please don’t do it.


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

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20 22

19. FUSE

The 1604-VLZ3 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 fl at 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 1604-VLZ3 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 fi nd out what to do.




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.

Press the bottom of this switch to turn off the mixer, whenever you feel that this would be a safe thing to do.

Half-way through Viking Warlord Ragnar's Heavy Metal guitar solo might not be such a good time.

23 21


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.

As a general guide, you should turn on your mixer fi rst, before the power amplifi er or powered speakers, and turn it off last. This will reduce the possibilities of any turn-on, or turn-off thumps in your speakers.


You’ve probably already fi gured 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.

23. 48V LED

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.

You’ll notice that when you turn the phantom power off, the LED stays on for a while. This is a natural phenomenon — 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.


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).


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