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11

Owner’s Manual

Owner’

s Manual

If you plug a cable into the left aux output 
jack, and leave the right output jack empty, 
the right and left signals are summed together 

to provide a mono output. 

The stereo aux output from these connectors is the 

sum of all channels whose aux level controls [16] are 
set to more than minimum. The aux bus gives you the 
chance to make a second mix or send an individual 
channel from the mixer, independent of the main level 
control [23] or channel level controls [17].

You could use the aux output to feed stage monitors, 

or to feed a headphone amplifier so you can wear head-
phones on stage. This lets you get a different mix than 
the audience is hearing, plus you get to look a lot cooler 
and surprisingly attractive with headphones on.

If you are going out to an external processor, you can 

return its processed output to one of the mixer’s line-
level input channels.

6. MAIN OUTs

These 1/4" TRS connectors provide stereo line-

level signals from the main mix. Connect these to 
the balanced inputs of the active speakers, or power 
amplifier(s) powering your main speakers.

The main mix is the sum of all active channels cur-

rently playing, including any 2 channel FireWire input. 
How much of a channel that is heard in the main mix, is 
determined by that channel’s level control [17].

If you plug a cable into the left output jack, 
and leave the right output jack empty, the 
right and left signals are summed together to 

provide a mono output.

Balanced 1/4" TRS connections offer better 
immunity to external noise (specifically, hum 
and buzz) than 1/4" TS unbalanced con-
nections. Because of this, it is the preferred 

interconnect method, especially in cases where very 
long lengths of cable are being used. A long unbalanced 
cable carries with it more opportunity for noise to get 
into the system — having balanced cables means very 
little noise will enter the system. If you must use an 
unbalanced connection, keep the cable length to 10 feet 
or less (3 meters).

7. HEADPHONES Output

This 1/4" TRS stereo jack is where you plug in your 

stereo headphones.

The headphone volume is controlled by the phones 

level control [22]. It is not affected by the main level 
control [23].

The headphones output is the main mix, taken just 

before the main level control [23]. 

Warning:

 The headphone amp is designed to 

drive any standard headphones to a very loud 
level. We’re not kidding! It can cause perma-

nent hearing damage. Even intermediate levels may be 
painfully loud with some headphones. Be careful! 

Always start with the phones level control turned all 
the way down before connecting headphones or making 
any connections. Keep it down until you’ve put on the 
headphones, and turn it down whenever you play a new 
source.

8. DC Input

This DC input connector is used to supply power to 

the mixer. Connect the supplied external power supply 
here, and plug the other end of the power supply into 
the AC mains. The power LED [18] will joyfully illumi-
nate, indicating that the mixer is powered on, and ready 
for some super fun.

The universal external power supply that comes with 

your mixer can accept any AC voltage from 100 VAC to 
240 VAC.

9. FIREWIRE Connection

FireWire (IEEE 1394) is a high-speed serial I/O inter-

face for connecting digital devices. The mixer has one 
FireWire connector for transferring digital audio to and 
from your computer.

The FireWire interface provides two audio outputs to 

your computer:

•  Main mix output, left and right. These output 

signals are independent of any adjustments 
made to the main level control [23]. This al-
lows you to easily record your live performance 
directly to your laptop.

•  The FireWire loop out switch [21] lets you 

choose if you want the FireWire input to be 
connected to the FireWire output for recording. 
See page 15 for more details of this switch.

The FireWire interface also lets you use your com-

puter to play back two channels into the mixer:

•  Left and right signals from your computer are 

added to the main mix. The FW in control [20] 
allows you to adjust the level of the incoming 
audio being added to the main mix.  

See Appendix D on page 21 for more FireWire details, 

and the block diagram on page 20. 

Summary of Contents for U.420

Page 1: ...AX 1 2 3 4 U O O MAX LEVEL U O O MAX U 14 14 U 14 14 MID LOW HIGH EQ GAIN 10 KILL U 10 KILL U U U 10 KILL U 10 KILL U 10 KILL U 10 KILL 10 KILL 10 KILL 10 KILL 10 KILL 10 KILL 10 KILL LEVEL SET LEVEL...

Page 2: ...18 This apparatus does not exceed the Class A Class B whichever is applicable limits for radio noise emissions from digital apparatus as set out in the radio interference regulations of the Canadian...

Page 3: ...AMS 6 REAR PANEL FEATURES 10 1 INSTRUMENT LINE INPUT 10 2 LINE INPUTS 10 3 PHONO INPUTS 10 4 GND TERMINAL 10 5 AUX OUTPUTS 10 6 MAIN OUTS 11 7 HEADPHONES OUTPUT 11 8 DC INPUT 11 9 FIREWIRE CONNECTION...

Page 4: ...d EQ on each channel with kill position Phono preamplifier on channel 4 accepts phono level stereo signals from a turntable Instrument level input option on channel 1 Stereo aux bus allows a separate...

Page 5: ...xer If you want to listen while you work plug headphones into the phones jack on the front panel then set the phones knob up a little 1 Play something into the selected input Be sure that the volume o...

Page 6: ...r for record ing with most DAW applications like Tracktion Cubase or Sonar This is independent of the Big Knob as well Additionally there is a stereo return from the laptop that has its own mix level...

Page 7: ...ing with most DAW applications like Tracktion Cubase or Sonar Perfect for recording your set Any play back software applications like Ableton Live or Tracktor can easily be part of your performance by...

Page 8: ...output is being sent to a pair of SRM150s on mic stands for stereo stage monitoring A laptop is connected via FireWire This laptop is loaded with awesome virtual instruments like those in applications...

Page 9: ...to channel 1 DVR decks connected to channels 2 and 3 and an iPod docking station connected to channel 4 The main outputs are fed to a pair of Mackie HR studio monitors for local monitoring and the mi...

Page 10: ...e will appear equally on the left and right of the main mix This does not apply to channel 4 3 PHONOInputs Channel 4 s RCA jacks accept stereo phono level signals from turntables Check that your turnt...

Page 11: ...meters 7 HEADPHONESOutput This 1 4 TRS stereo jack is where you plug in your stereo headphones The headphone volume is controlled by the phones level control 22 It is not affected by the main level c...

Page 12: ...players keyboards drum machines and tape players You will need a DI box if connecting instrument level signals to the inputs when this switch is out 12 GAIN These knobs allow you to adjust the gain o...

Page 13: ...In the center position U low EQ has no effect The frequency range below 300 Hz represents the realm of bass drums bass guitar fat synth patches and lower down to some really serious male singers 16 AU...

Page 14: ...blink occasionally or not at all 20 FWIN This control lets you adjust the signal level of the two FireWire channels coming in from your computer rela tive to the mix of channels 1 to 4 Adjust it care...

Page 15: ...the way down before connecting headphones or making any connec tions Keep it down until you ve put on the headphones and turn it down first whenever you play a new source or instrument 23 MAINLEVEL T...

Page 16: ...y you ll know which input source is causing the problem It helps to plug all the audio equipment into the same AC circuit so they share a common ground If the annoying humming continues ask the drum m...

Page 17: ...visit www mackie com click Support and select Locate a Service Center Service for Mackie products living outside the United States can be obtained through local dealers or distributors If you do not h...

Page 18: ...Unbalanced Wiring Sleeve Shield Tip Left Ring Right 1 4 TS Phone Plugs and Jacks TS stands for Tip Sleeve the two connection points available on a mono 1 4 phone jack or plug They are used for unbalan...

Page 19: ...ed 0 0 5 dB Distortion THD N Main and aux output 20 Hz to 20 kHz 1 kHz input signal Line input at unity gain 4 dBu input signal Better than 0 008 Phono input at unity gain 30 dBu input signal Better t...

Page 20: ...O HI MID Main Out R Aux Out R Phones Channel 4 Aux R Aux Level L R 3 Band EQ Gain LO HI MID LO HI MID Aux L Phono R Level Channel 1 L R 3 Band EQ LO HI Z HI MID LO HI MID Aux HI Z Normal FireWire In f...

Page 21: ...om the mixer is converted to digi tal signals by the FireWire interface s A D converters The following table shows the outputs to your com puter from the FireWire interface Here are two examples of us...

Page 22: ...separate virtual mixer for monitoring The U 420 ALWAYS provides zero latency monitoring by design without any extra configuration Hurrah Due to the nature of its signal path the U 420 requires the use...

Page 23: ...r guitar string to the moment you hear it in your headphones You are used to this la tency being very close to zero when you play your guitar through a guitar amp you hear the signal immediately So wh...

Page 24: ...e U 420 CD ROM into your PC s CD ROM drive 3 Click Start in the task bar then click Run and click Browse Browse to your CD drive and double click _SETUP EXE Then click OK to start the installation 4 T...

Page 25: ...you are ready to use the FireWire capabili ties of your U 420 Console PConly You should adjust the sample rate and latency from within your audio software application for example in Tracktion s setti...

Page 26: ...settings for the U 420 You can also choose the U 420 as your default input or output as well as designate it to be used for the system sound output 5 You re ready to go with any Mac OS X Core Audio h...

Page 27: ...t to an authorized service center The return ground shipment is covered for those units deemed by us to be under warranty Note You must have a sales receipt from an authorized Mackie dealer for your u...

Page 28: ...Road NE Woodinville WA 98072 USA United States and Canada 800 898 3211 Europe Asia Central and South America 425 487 4333 Middle East and Africa 31 20 654 4000 Fax 425 487 4337 www mackie com E mail s...

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