| 4-Channel Mic/Line Mixer with FireWire and DJ Features   O W N E R ’ S M A N U A L   1 2 3 4 LEVEL   SET   LEVEL   SET   MIC   MIC   U U GAIN   GAIN   +3   +50   +3   +50   POWER   48V   -14   +14   -14   +14   -22   +25   -22   +25   U U U U U U U U EQ   HIGH   12kHz   EQ   HIGH   L R -15   -15   100   -15   +15   +15   8k   -15   -15   100   -15   +15   +15   8k   KILL   KILL   KILL   +10   KILL   KILL   KILL   +10   U U OL   10   7 MID   MID   +10   +10   4 600   600   0 MID   FREQ   4 150   1.5k   150   1.5k   LOW   10   20   +10   +10   U U AUX   LOW   80Hz   O O   O O   +15   +15   MAX   MAX   MAX   MAX   U U AUX   CUE   LEVEL   48V   O O   O O   O O   O O   MAX   MAX   CUE   CUE   CUE   CUE   CURVE   SLOW   FAST   O O   O O   PHONES   MAX   FW IN   MAX   +10   5 0 -5   LOOP   OUT   3 4 -10   -20   O O   MAX   O O   Download from Www.Somanuals.com. All Manuals Search And Download.   Table of Contents   SOFTWARE INSTALLATION............................... 28   IMPORTANT SAFETY INSTRUCTIONS ........................ 2   INTRODUCTION ...................................................... 4   GETTING STARTED................................................... 5   HOOKUP DIAGRAMS............................................... 6   Need help with your new U.4ꢀ0d mixer?   FAQs, manuals, addendums, and user forums.   • Telephone 1-800-898-ꢁꢀ11 to speak with one of our splendid   technical support representatives, (Monday through Friday,   from 7 a.m. to 5 p.m. PST).   Part No. SW0557 Rev. D 02/08   ©2007-2008 LOUD Technologies Inc. All Rights Reserved.   ꢁ Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   • • • Separate FireWire modes for live performance   or overdubbing.   Introduction   Ultra-compact design, with functional and   ergonomic controls.   Thank you for choosing a Mackie U.420d mixer. It con-   tains all your favorite features in a ultra-compact mixer,   along with a built-in FireWire interface, easy controls   and a crossfader.   Stereo channels have a crossfader with a choice   of contour curves.   • • Faders on mono channels.   The U.420d is equally at home in recording studio ap-   plications or in live performances:   3-Band EQ on each channel, with kill position   on stereo channels, and sweepable Mid fre-   quency on the mono channels.   In the recording studio, the mixer offers Mackie-qual-   ity sound to sub-mix outboard gear and bring it into the   computer. It has 2 stereo channels that can accept any   stereo device from synths, samplers, or turntables and   bring it directly into the DAW. It can interface a DJ rig   right to the DAW as well. Two mono channels allow mic   or line connections, and channel one also accepts an   instrument connection without the need for a DI box.   • Mic preamplifier on each mono channel, with   phantom power selection.   • • • Phono preamplifiers on each stereo channel.   Instrument-level input option on channel 1.   Stereo aux bus allows a separate mix to be sent   to stage monitors or external processors.   • • • • • TRS stereo main outputs.   In live performances, the mixer will enable you to sub-   mix synths, computers, samplers, pedal boards, turn-   tables, CD-players, microphones, and effects on stage in   your rig. Bands and solo artists from DJs, electronic art-   ists and singer/songwriters can use the mixer to sub-mix   their creative tools and deliver them to the sound board,   and send an aux mix to stage monitors.   TRS stereo headphone out.   TRS stereo aux bus outputs.   Stereo main meters with overload lights.   Cue system for cueing each channel in the   headphones.   • • • Large, easy to use, main level control.   External universal power supply.   Generally speaking, the U.420d mixer is way up there   with sliced bread and Swiss army knives. (Swiss army   bread?) We hope that you will just love it, as much as we   did making it for you.   Includes Tracktion, our professional, easy-to-   use, totally-amazing music production software.   FEATURES   HOW TO USE THIS MANUAL   • • • 2 stereo channels with line-level and phono-   level inputs.   Please read the safety instructions on page 2 first.   The getting started guide on page 5 will help you get the   mixer set up fast so you can start using it right away.   Right after that are the ever-popular hook-up diagrams   that show you some typical setups.   2 mono channels with mic-level and line-level   inputs.   Built-in FireWire 2x2 interface provides easy   input from computer to the main mix, and easy   outputs to the computer from the main mix. It   has 24-bit resolution, and 44.1, 48, 88.2, and   96 kHz sample rates.   The features section describes every knob, button,   and connection point on the mixer, roughly following   the signal flow through the mixer from top to bottom.   For more information about a feature, locate its number   in the appropriate illustration, and find it in the nearby   paragraphs.   Please write your serial number here for future   reference (i.e., insurance claims, tech support,   return authorization, etc.)   This icon marks information that is critically   important or unique to the mixer. For your   own good, read them and remember them.   This icon leads you to in-depth explanations   of features and practical tips. They usually   have some valuable nuggets of information.   Purchased at:   This icon marks information that was   dreamed up while the technical writer was   curled up asleep under his desk.   Date of purchase:   Appendix A shows service and repair information.   Appendix B is a section on connectors.   Appendix C shows the specs and a block diagram.   Appendix D shows details of the FireWire interface.   4 U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Set the Levels   Getting Started   To set the gain controls, it’s not even necessary to   hear what you’re doing at the outputs of the mixer. If   you want to listen while you work, plug headphones into   the phones jack on the front panel, press the cue switch   on that channel, then set the phones knob up a little.   READ THIS PAGE!!   Even if you never read manuals, please   read and digest the safety instructions   on page 2, and this page before you   begin using your mixer.   1. Play something into the selected input. Be sure   that the volume of the input source is the same as   it would be during normal use. If it isn’t, you might   have to readjust these levels during the middle of a   set.   Zero the Controls   1. Unplug the mixer’s external power supply from the   mixer.   2. Adjust the channel’s rotary gain control so that the   level set LED comes on while you are playing, and   goes off when you stop. As a rough guide, adjust   the gain until the LED is on for about half the time   of your performance. (The LED indicates that the   signal level is 0 dBu.)   2. Turn down all the gain, aux, and level controls, and   center all the EQ controls.   3. Set all push button switches to their “out” positions.   3. Repeat for the other channels (if you want to).   4. In the center section, turn down the large level   knob, FW in knob, and phones level knob.   5. Set the program faders fully down, and center the   crossfader.   Instant Mixing   1. To get sound out of the speakers, turn up the   channel’s fader, or level, and slowly rotate the main   control to a comfortable listening level.   Connections   2. Sing and play. You’re a star! Bring in the other   channels, play with the crossfader, and generally   have fun.   If you already know how you want to connect the   mixer, go ahead and connect the inputs and outputs   the way you want them. If you just want to get sound   through the mixer, follow these steps:   1. Plug a signal source into the mixer. This could be a:   FireWire   • • • Microphone into an XLR mic input.   Turntable into a phono input.   1. See Appendix D, page 25 for details of getting   started with FireWire.   Line-level source such as a CD player into a   TRS line-level input.   2. There is a nice section about recording with   FireWire on page 26.   • A guitar connected to the input 1, with the   instrument switch pressed in.   Other Nuggets of Wisdom   2 . Connect cords from the main outputs to the line-   level inputs of your powered speakers or amplifier.   • Always turn down the main level knob and phone   knob before making any connections.   3. Plug in the mixer’s external power supply, and con-   nect it to a live AC outlet to turn on the mixer.   • When you shut down your equipment, turn off the   amplifiers first. When powering up, turn on the   amplifiers last.   4. If you have powered speakers, turn them on. Other-   wise, hook up your speakers to your amp and turn it   on. Adjust your powered speaker or amplifier level   controls to however the manufacturer recommends.   (This is usually all the way up.)   5 Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   Hookup Diagrams   Acoustic Guitar   and Mic   HR824   Powered   Monitors   Studio   Vocal   Mic   Headphones   MAIN   L 4 PHONO   L LINE 3   2 1 GND   OUT   T   LINE   MINE   MIE   ON L L PHONO   L POWER   18V,1.5A   R R R R R Laptop   Electric   Guitar   Synth workstation   USB Combo keys/pads   Controller   Amplifier   modeller   This diagram shows an acoustic guitar microphone attached to channel 1’s XLR input, a vocal condens-   er microphone connected to channel 2’s XLR input, a guitar and amp modeler (like a Line 6 Pod™) con-   nected to channel 3, and a synthesizer workstation connected to channel 4. A northbound train loaded   with pig-iron is leaving Little Rock at 3:30.   The main outputs are fed to a pair of Mackie HR studio monitors for control room listening, and the   mixer’s Big Knob controls their volume. The headphone output has its own level control, and each chan-   nel has a cue switch independent of the Big Knob.   A laptop is connected via FireWire. The mixer provides stereo mains to the computer for recording with   most DAW applications like Tracktion, Cubase™ or Logic™. This is independent of the Big Knob as well.   The laptop is loaded with awesome virtual instruments like those in applications such as Logic, and a   USB key/pads combo controller is connected for real-time performance and recording.   The FireWire loop through switch on the top of the mixer makes overdubbing a breeze. In it’s normal   “out” position, you can playback the mix from your DAW and it will not loop back through the FireWire.   Only the analog inputs 1-4 will be available for recording. Track it!   Music Production Studio 1   ꢂ U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Acoustic Guitar   and mic   HR824   Powered   Monitors   Synth workstation   Studio   Vocal   Mic   Headphones   MAIN   OUT   AU OU L 4 PHONO   L LINE 3   2 1 GN LINE   MINE   MINE   (MONO)   L L PHONO   L POWER   18V,1.5A   R R R Drum   Machine   ground wire   USB   Keyboard   Controller   Laptop   Turntable with phono-level output   Turntable with phono-level output   This diagram shows an acoustic guitar microphone attached to channel 1’s XLR input, a vocal condens-   er microphone connected to channel 2’s XLR input, two turntables are connected to channel 3 and 4’s   phono inputs, and a drum machine and keyboard workstation are attached to their line inputs.   Note: Each turntable is disconnected whenever a 1/4” plug is inserted into a line input on the same   channel, so physically pull out the 1/4” plug whenever you want to play a record.   The main outputs are fed to a pair of Mackie HR studio monitors for control room listening, and the   mixer’s Big Knob controls their volume. The headphone out has its own level control independent of the   Big Knob.   A laptop is connected via FireWire. The mixer provides stereo mains to the computer for recording with   most DAW applications like Tracktion, Cubase, or Logic. This is independent of the Big Knob as well. The   laptop is loaded with awesome virtual instruments like those in applications such as Logic, and a USB   key/pads combo controller is connected for real-time performance and recording.   The FireWire loop through switch on the top of the mixer makes overdubbing a breeze. In it’s normal   out position, you can play back the mix from your DAW and it will not loop back through the FireWire.   Only the analog inputs 1-4 will be available for recording. Track it!   Music Production Studio 2   7 Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   SRM450   Powered   Speakers   pole   pole   Microphone   mount   mount   SWA1501   Powered   Subwoofers   MAIN   OUT   AUX   OUT   L 4 PHONO   L LINE 3   2 G LINE   MNE   MIC/LINE   (MONO)   L L PHONO   L POWER   18V,1.5A   R R R R R Keyboards   Laptop   SRM350 Powered Stage Monitors   Electronic Drum Kit   This diagram shows an electric/acoustic guitar connected to input 1’s 1/4” input, a vocal microphone   connected to channel 2’s XLR input, a keyboard connected to input 3, and an electronic drum kit con-   nected to channel 4’s line input.   The main outputs are fed to a pair of Mackie SRM450s and subwoofers for the audience’s listening   pleasure. The mixer’s Big Knob controls their volume. Use the left aux send to connect to 4 SRM350s for   stage monitoring. (The mixer automatically sums the stereo signal to mono if you use the left channel   output only.)   A laptop is connected via FireWire. The mixer provides stereo mains to the computer for recording with   most DAW applications like Tracktion, Cubase or Sonar™. Perfect for recording your set. Any playback   software applications like iTunes™, or Tracktor™ can be used for break music by utilizing the FireWire   stereo return with its own mix level control into the mains.   Music Performance System   8 U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Guest MC   Mic   DJ   Mic   SRM350   Powered   Speakers   SRM450   Powered   Speakers   Headphones   MAIN   OUT   AUX   OUT   L 4 PHONO   L LINE 3   2 1 GN E   MNE   MINE   (MONO)   L PHONO   L POWER   18V,1.5A   R R R ground wire   ground wire   Laptop   Turntable with phono-level output   Turntable with phono-level output   This diagram shows two microphones connected to channel 1 and 2, and two turntables connected to   channel 3 and 4’s phono inputs.   The main outputs are fed to a pair of Mackie SRM450s for the audience’s listening pleasure. The mix-   er’s mighty Big Knob controls their volume. Use the stereo aux send to connect 2-SRM350s for the booth.   A laptop is connected via FireWire. The U.420d provides stereo mains to the computer for recording   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   utilizing the FireWire stereo return that has its own mix level control into the mains.   The FireWire loop through switch on the top of the mixer allows you to send your FireWire return   through the FireWire output for recording. So use Ableton Live and your analog inputs to perform, and   record it all at the same time on Tracktion or your DAW of choice. The switch should be pressed in to al-   low loop-through of the FireWire return to the FireWire record output.   DJ Performance System   9 Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   To on-air feed   Broadcast   Microphones   SRM450   Powered Speakers   (Location PA)   Headphones   MAIN   OUT   AUX   L 4 PHONO   L LINE 3   2 1 G OUT   LINE   MINE   MIE   (MONO)   L L PHONO   L POWER   18V,1.5A   R R R R R Laptop   Telephone Patch   Hybrid Interface   Broadcast Playback Device   Incoming dedication   of the next song to your   girlfriend Sharon   This diagram shows two broadcast vocal microphones connected to channels 1 and 2, for two hosts   (the on-air talent). A broadcast playback device (such as a 360 Systems™ Instant Replay™) is connected   to channel 3. A telephone hybrid interface is connected to channel 4 inputs via a mono “Y” cable. The   left aux output feeds the telephone hybrid input.   The main outputs are sent to the on-air feed, and/or to a pair of Mackie SRM450 speakers for location   PA. (Typically, by a left/right split, i.e. the right channel connects to the on-air feed and the left channel   goes to the first SRM450, then loops through to another SRM450) – the mixer’s Big Knob controls their   volume. The headphone out has its own level control, independent of the Big Knob.   The Aux send provides audio to the telephone patch or “hybrid” for placing callers on the air. Chan-   nels 1,2 & 3 are turned up (ideally to unity gain) so the caller can hear the on-air talent and any music   playback, but not their own channel’s (ch 4) signal.   The FireWire loop through switch on the top of the mixer is in its normal out position, so you can record   the mix of the broadcast to a DAW program on the laptop. Only the analog inputs 1– 4 will be recorded.   Best of all, you can still play back audio from the laptop for broadcast, without it looping back into the   U.420d.   Broadcast/Radio Remote   10   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Rear Panel Features   MAIN   OUT   AUX   OUT   L 4 PHONO   L LINE 3   2 1 GND   LINE   MIC/LINE   MIC/LINE   (MONO)   L L PHONO   L POWER   18V,1.5A   R R R R R These are stereo inputs; the left signals appear on the   left main mix bus, and the right signals appear on the   right main mix bus.   1. MIC/LINE Input   These Neutrik “combo” input connectors for channels   1 and 2 accept either balanced male XLR connectors, or   1/4" TRS balanced or TS unbalanced connectors.   If you have a turntable with a phono-level output, use   the phono RCA inputs [3] instead.   • If you are using a microphone, use the XLR   input. (Professional mics usually have XLR con-   nectors, while consumer or semi-pro mics often   have 1/4" connectors.)   ꢁ. PHONO Inputs   These RCA jacks for channels 3 and 4 accept stereo   phono-level signals from turntables. Check that your   turntable has a phono-level output and a moving-mag-   net cartridge. Turntables usually have a ground wire   that needs to be connected to the ground terminal [4].   • If you are connecting line-level sources such as   CD or MP3 players, use the 1/4" input.   Input 1 can also accept direct instrument-level signals   such as from guitars, without the need for a DI box. For   this to work, use the 1/4" input, and press channel 1’s   instrument switch [11].   The turntable’s stereo phono-level signals are re-   equalized and converted to line-level by the fine RIAA   preamplifiers inside the mixer.   Channel 1 and 2 are mono, and the signals are equally   split to the left and right of the main mix bus.   The phono inputs are internally disconnected   if anything is plugged into the same channel’s   line inputs.   If your microphone is a condenser design, it probably   requires phantom power to operate. Push in the 48V   switch [32] to supply 48 VDC to pins 2 and 3 of both   XLR microphone connectors. Do not use phantom power   with ribbon microphones.   Do not connect line-level sources to these   inputs, because the phono preamplifiers will   be overloaded. Use the line-level inputs [2]   instead.   ꢀ. LINE Inputs   4. GND Terminal   Channel 3 and 4 have stereo line-level inputs that   accept either 1/4" TRS balanced or TS unbalanced con-   nectors.   This terminal is provided to connect a ground wire   from your turntable(s) to the mixer. Most turntables   provide a ground wire for the purpose of eliminating   hum in the audio signal.   You can connect stereo line-level sources such as CD   players, MP3 players, keyboards, drum machines, tape   players, and all manner of line-level goodies. You may   need to purchase some adapters from RCA to 1/4" mono,   depending upon your source component. These adapters   are readily available at your local music or electronics   store.   Rotate this terminal counter-clockwise to loosen it,   wrap the end of the turntable’s ground wire clockwise   around the terminal, and hand-tighten the terminal for   a secure ground connection.   11   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   MAIN   OUT   AUX   OUT   L 4 PHONO   L LINE 3   2 1 GND   LINE   MIC/LINE   MIC/LINE   (MONO)   L L PHONO   L POWER   18V,1.5A   R R R R R Balanced 1/4" TRS connections offer better   immunity to external noise (specifically, hum   and buzz) than 1/4" TS unbalanced connec-   5. AUX Outputs   These 1/4" TRS outputs provide stereo line-level   tions. 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).   output signals from the aux bus. You can connect these   outputs to the inputs of an external effects processor,   another PA system, or stage monitors. You can also use   unbalanced 1/4" TS connectors.   The stereo aux output is the sum of all channels   whose aux level controls [17 or 24] are set to more than   minimum. This gives you the chance to make a second   mix or send an individual channel from the mixer, inde-   pendent of the main level control [36].   7. HEADPHONES Output   You could use the aux output to feed stage monitors,   or to feed a headphone amplifier so you can wear head-   phones and look cool on stage. You will hear a different   mix than the audience is hearing.   This 1/4" TRS stereo jack is where you plug in your   stereo headphones.   The headphone volume is controlled by the phones   level control [35]. It is not affected by the main level   control [36].   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 headphones output is either the main mix, taken   just before the main level control, or, if a cue button   [18] is pressed, the headphones play back the cue bus   instead. This allows you to cue up a source in the head-   phones before turning up its fader and adding it to the   main mix. The cue light [31] reminds you if any channel   has its cue button engaged.   If you are going out to an external processor, you can   return its processed (wet) output to one of the mixer’s   line-level input channels.   ꢂ. MAIN Outputs   Warning: The headphone amp may drive   the headphones to a loud level. It can cause   permanent hearing damage. Even intermedi-   ate levels may be painfully loud with some headphones.   Be careful!   These 1/4" TRS outputs provide stereo line-level sig-   nals 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, and any FireWire input. How much of   each channel that is heard in the main mix, is de-   termined by each channel’s level control, and by the   crossfader.   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 head-   phones, and turn it down whenever you press cue.   If you plug a cable into the left main output   jack, and leave the right output jack empty,   the right and left signals are summed together   to provide a mono output.   1ꢀ   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   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 [28] will joyfully illumi-   nate, indicating that the mixer is powered on, and ready   for action.   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 [36]. This al-   lows you to easily record your live performance   directly to your laptop.   • The FireWire loop out switch [34] lets you   choose if you want the FireWire input to be   connected to the FireWire output for recording.   See page 19 for more details of this switch.   The FireWire interface also lets you use your com-   puter to playback two channels into the mixer:   • Left and right signals from your computer are   added to the main mix. The FW in control [33]   allows you to adjust the level of the incoming   audio being added to the main mix.   See Appendix D on page 25 for more FireWire details,   and the block diagram on page 24.   1ꢁ   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   Top Panel Features   1 2 3 4 LEVEL   SET   LEVEL   SET   MIC   MIC   U U GAIN   GAIN   +3   +50   +3   +50   POWER   48V   -14   +14   -14   +14   -22   +25   -22   +25   U U U U U U U U HIGH   12kHz   EQ   HIGH   L R -15   -15   100   -15   +15   +15   8k   -15   -15   100   -15   +15   +15   8k   KILL   KILL   KILL   +10   KILL   KILL   KILL   +10   U U OL   10   7 MID   MID   +10   +10   4 600   600   0 MID   FREQ   4 150   1.5k   150   1.5k   LOW   10   20   +10   +10   U U AUX   LOW   80Hz   O O   O O   +15   +15   MAX   MAX   MAX   MAX   U U AUX   CUE   LEVEL   48V   O O   O O   O O   O O   MAX   MAX   CUE   CUE   CUE   CUE   CURVE   SLOW   FAST   O O MAX   FW IN   O O MAX   PHONES   +10   5 0 -5   LOOP   OUT   3 4 -10   -20   O O   MAX   O O   When this switch is out, input 1 is just like input 2,   and you will need a DI box if connecting instrument-   level signals to the inputs.   Channel 1 and 2 controls   Channel 1 and 2 are mono channels, fed by the combo   input connectors [1]. The controls are mono, but the   final output of each channel is split equally and added   to the left and right main mix.   1ꢀ. GAIN   This knob adjusts the gain of the preamp for any mi-   crophone or line-level source you care to plug into the   input jacks [1].   10. LEVEL SET LED   These LEDs are used with the gain control [12] to set   the level of the channel’s preamplifier gain just right.   They light when the signal level is 0 dBu.   The gain ranges from +3 dB to +50 dB of gain for   microphone-level signals coming in on the XLR inputs,   and from –22 dB to +25 dB for line-level signals coming   in on the 1/4" TRS inputs. Adjust the gain control so the   level set LEDs [10] come on while you are playing, and   go off when you stop. As a rough guide, adjust the gain   until the LEDs are on for about half the time during   your performance. This gives you the best signal-to-   noise ratio for the preamp.   Adjust the gain control so these LEDs come on while   you are playing, and go off when you stop. As a rough   guide, adjust the gain until the LED is on for about half   the time during your performance.   Setting the gain correctly will ensure that the pre-   amplifier’s gain is not too high, where distortion could   occur, and not too low, where your quieter, exquisitely-   delicate performance might be lost in background noise.   Adjust the gain after plugging in any input, or playing   a new source or instrument for the first time.   11. INSTRUMENT SWITCH   When this is pressed in, channel 1’s 1/4" TRS input   can accept direct instrument-level signals from guitars   or other instruments. They will be impedance-matched   to the channel 1 input, without the need for a DI box.   14   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   ꢁ-BAND EQ   17. AUX   The mono channels have 3-band equalization at   carefully selected points — low shelving at 80 Hz, mid   peaking at a variable frequency from 100 Hz to 8 kHz,   and high shelving at 12 kHz.   These controls allow you to adjust how much of the   channel signal is added to the aux bus. The aux bus   contains the sum of all channels whose aux controls   [17, or 24] are set to more than minimum. For the mono   channels 1 and 2, the aux signals are split and sent to   both left and right aux bus. The aux bus feeds the aux   outputs [5], typically out to an external processor.   “Shelving” means that the circuitry boosts or cuts all   frequencies past the specified frequency. For example,   rotating the low EQ knob clockwise will boost the bass   at 80 Hz and below.   • The aux output is affected by the gain, EQ, and   aux level of each channel.   “Peaking” means that certain frequencies form a “hill”   around the center frequency in the case of the mid EQ.   • The aux output is not affected by the fader level   control of each channel, and it is independent   of the main mix bus.   There is a lot of boost and cut available, be-   cause you may occasionally need it, but if you   max the EQs on every channel, you’ll get mix   For an example of using the aux bus, you could set up   a stage monitor for the guitar player. Connect an ampli-   fier or a powered monitor to the aux outputs [5]. Set all   aux level controls to minimum, then turn up the guitar   channel’s aux level to suit his tone-deaf hearing. Any   adjustments of the faders [19] or main level [36] will   not affect the stage monitor level, so your guitar player   will be happy.   mush. Equalize subtly and use the left sides of the knobs   (cut), as well as the right (boost). You can create many   interesting and useful EQ changes by turning the knobs   down and adjusting the faders [19] up if needed.   1ꢁ. HIGH EQ   This knob gives the channel signal up to 15 dB of   boost and cut at 12 kHz and above. At the center posi-   tion the high EQ has no effect on the signal.   18. CUE   Normally, what you hear in your headphones is the   main mix. If you press cue, then your headphones are   switched internally to listen to the channel that is cued.   This gives you the chance to listen to a source before   you turn up its fader [19] and add it to the main mix.   The cue switches do not affect the main mix, just the   headphones.   Use it to add sizzle to cymbals, and an overall sense   of transparency, or edge to keyboards, vocals, guitar and   bacon frying. Turn it down a little to reduce sibilance, or   to hide tape hiss.   14. MID EQ   Turn down the phones level [35] before you press   cue, as this will protect your hearing if you have a loud   source playing.   This knob gives you up to 15 dB of boost and cut at   a frequency set by the mid freq [15] control. At the   center position the mid EQ has no effect on the signal.   The mixer contains a left and right cue bus, so you   will hear left and right mono in the headphones for   channels 1 and 2, and stereo for channels 3 and 4. If you   have more than one cue button engaged, then you will   hear a mix of all cued channels. The cue light [31] will   also come on as a reminder that you are not listening to   the main mix in the headphones.   Midrange EQ is often thought of as the most dynamic,   because the frequencies that define any particular   sound are almost always found in this range.   15. MID FREQ   This knob allows you to set the frequency of the mid   EQ control. It varies from 100 Hz up to 8 kHz, with a   frequency of 600 Hz when centered.   19. FADERS   These custom faders allow you to adjust how much of   the channel signal appears on the main mix bus. They   have no effect on the level of signals going onto the aux   bus or the cue bus. (If the faders are all the way down,   the channels can still be cued and heard in the head-   phones, or added to the aux bus.)   1ꢂ. LOW EQ   This knob gives you up to 15 dB of boost and cut at   80 Hz and below. At the center position the low EQ has   no effect on the signal.   After the fader, the mono channels are split and added   to the left and right main mix.   Frequencies below 80 Hz represent the realm of bass   drums, bass guitar, fat synth patches, and lower down to   some really serious male singers.   15   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   1 2 3 4 LEVEL   SET   LEVEL   SET   MIC   MIC   U U GAIN   GAIN   +3   +50   +3   +50   POWER   48V   -14   +14   -14   +14   -22   +25   -22   +25   U U U U U U U U HIGH   12kHz   EQ   HIGH   L R -15   -15   100   -15   +15   +15   8k   -15   -15   100   -15   +15   +15   8k   KILL   KILL   KILL   +10   KILL   KILL   KILL   +10   U U OL   10   7 MID   MID   +10   +10   4 600   600   0 MID   FREQ   4 150   1.5k   150   1.5k   LOW   10   20   +10   +10   U U AUX   LOW   80Hz   O O   O O   +15   +15   MAX   MAX   MAX   MAX   U U AUX   CUE   LEVEL   48V   O O   O O   O O   O O   MAX   MAX   CUE   CUE   CUE   CUE   CURVE   SLOW   FAST   O O   O O   PHONES   MAX   FW IN   MAX   +10   5 0 -5   LOOP   OUT   3 4 -10   -20   O O   MAX   O O   Channel 3 and 4 controls   Channel 2 and 3 are identical stereo channels, fed by   the line-level input connectors [2] or the phono-level   ꢀ1. HIGH EQ   This knob gives your channel signal up to 10 dB of   boost at 4 kHz and above. In the kill position, the high   frequency range above 4 kHz are muted. In the center   position the high EQ has no effect on the signal.   inputs [3]. The controls are stereo, and the final output   of each channel is added to the left and right main mix.   These channels are set up with a crossfader, ideal for   DJ work with two turntables. The EQ controls are also   DJ-friendly with a kill position, where each frequency   band can be turned fully off if needed.   If all three EQ controls are set to kill, then the channel   is effectively muted.   The controls are much the same as the mono chan-   nels 1 and 2, but there are enough differences in the   details to justify an extra page or two.   ꢀꢀ. MID EQ   This knob gives you up to 10 dB of boost at 1 kHz. In   the kill position, the mid frequency range around 1 kHz   is muted. At the center position, the mid EQ has no ef-   fect on the signal.   ꢀ0. GAIN   This knob adjusts the gain of the stereo preamp.   Signals from the line-level input jacks [2] go straight to   the preamp and this control. Phono-level signals enter-   ing the phono inputs [3] are first passed through an   RIAA phono preamplifier to become line-level.   ꢀꢁ. LOW EQ   This knob gives you up to 10 dB of boost at 300 Hz   and below. In the kill position, the low frequency range   below 300 Hz is muted. At the center position, the low   EQ has no effect on the signal.   The gain ranges from –14 dB to +14 dB, and it should   be adjusted so that the level set LEDs [10] are on for   about half the time during your performance. This gives   you the best signal-to-noise ratio for the preamp.   1ꢂ   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   ꢀ4. AUX   ꢀꢂ. CURVE   These stereo controls allow you to adjust how much   of the channel signal is added to the aux bus. The aux   bus contains the sum of all channels whose aux controls   [24, or 17] are set to more than minimum. The aux bus   feeds the aux outputs [5], typically out to an external   processor. The aux bus is stereo, so the left and right   aux signals are separate and may be used for feeding   stereo processors for example.   This switch affects how the crossfader operates, and   allows for some fast crossfading DJ work:   In the slow position (up), the crossfade from chan-   nel 3 to channel 4 occurs linearly over the complete   movement of the crossfader. For example, channel 3 is   maximum and channel 4 minimum when the crossfader   is fully left, and channel 3 is minimum and channel 4   maximum when the crossfader is fully right.   See aux [17] on page 15 for more details.   In the fast position (down), the crossfade from chan-   nel 3 to channel 4 occurs over a small movement of the   crossfader. For example, channel 3 is maximum and   channel 4 minimum when the crossfader is fully left,   and channel 3 is minimum and channel 4 maximum   when the crossfader is moved just slightly to the right.   ꢀ5. LEVEL   These level controls allow you to adjust how much of   the channel signals appear on the main mix bus. They   have no effect on the level of signals going onto the aux   bus, but they do affect the levels going onto the cue bus   if the cue button [18] is pressed.   ꢀ7. CROSSFADER   After the level control, the stereo signals are sent   through a voltage controlled amplifier (VCA) that is af-   fected by the position of the crossfader [27].   The crossfader is used to fade between channel 3 and   4 in the main mix bus. It has no effect on the aux bus, or   the headphones when cue is enabled   When the crossfader moves left, then channel 3 in-   creases in volume in the main outputs, while channel 4   decreases in volume. When the crossfader moves to the   right, channel 4 increases while channel 3 decreases.   With two turntables connected to channels 3 and 4,   the crossfader allows you to set up and run a nice DJ   system.   The characteristics of how the crossfader affects the   audio signal are determined by the curve switch [26].   17   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   ꢁ0. METERS   These meters have 8 LEDs each, ranging from –20 to   +13.5 (OL). They indicate the stereo signal strength of   the main mix after the main level control [36].   POWER   48V   R L Typically, you want to see these meters bouncing   between the “0” and the “+4” LEDs. It is okay if the OL   LEDs light occasionally, but if they light frequently or   continuously, turn down the main level control until the   OL LEDs blink occasionally or not at all.   OL   10   7 4 0 4 10   20   ꢁ1. CUE LED   This large LED will light whenever a cue switch [18]   is engaged. This acts as a reminder that, in your head-   phones, you are listening to those channels whose cue   switch is engaged, and not the main mix.   CUE   48V   O O   O O   PHONES   MAX   FW IN   MAX   ꢁꢀ. 48V   LOOP   OUT   If your microphone is a condenser design, it probably   requires phantom power to operate. Push in this switch   to supply 48 VDC to pins 2 and 3 of the XLR microphone   connector.   MAX   O O   Dynamic microphones, like Shure’s SM57   and SM58, do not require phantom power.   However, phantom power will not harm most   dynamic microphones should you accidentally plug one   in while the phantom power is turned on. Do not use   phantom power with ribbon microphones, as they may   be damaged. Check your microphone’s user’s manual   if you are not sure whether your microphone needs   phantom power.   Control Section   ꢀ8. POWER LED   This will light whenever the external power supply   is connected to the mixer and is supplying the correct   DC voltage. The mixer does not have a power switch, so   as long as the external power supply is connected and   operating, the mixer is powered up and this LED should   be on.   ꢁꢁ. FW IN   This control lets you adjust the signal level of the   two FireWire channels coming in from your computer,   relative to the mix of channels 1 to 4. Adjust it carefully   to achieve the desired mix with the other channels. (If   the mono-channel faders [19] or stereo-channel level   controls [25] are turned down, then the meters will   show the level of the FireWire input only.)   ꢀ9. 48V LED   This LED will light when the 48V switch [32] is en-   gaged. It acts as a reminder that 48 VDC phantom power   is supplied by the mixer to any microphones connected   to the mic inputs [1].   The FireWire input from your audio software such as   Tracktion, could be individual instrument tracks, a mix   of tracks, or processed tracks.   18   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   ꢁ4. FW LOOP OUT   ꢁ5. PHONES LEVEL   In addition to a mix of channels 1 to 4, the FireWire   output to the computer can contain the FireWire input   signal, if this switch is down. The mains and phones are   not affected by the switch, and always provide a full mix   of channels 1 to 4 and the 2-channel FireWire inputs.   This controls the volume of the headphones output   from off to maximum gain.   Warning: The headphone amplifier is de-   signed to drive any standard headphones to   a loud level. It can cause permanent hearing   damage. Even intermediate levels may be painfully loud   with some headphones. Be careful!   • If disengaged (out), the FireWire output to   your computer will just be the main mix from   channels 1 to 4. This is a good position for   overdubbing, as any playback from your com-   puter can be played in your main speakers and   headphones, while you play along with a guitar   and record only the guitar via FireWire.   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 head-   phones, and turn it down first whenever you press cue.   1 2 3 4 U U LEVEL   ꢁꢂ. MAIN LEVEL   O O   O O   MAX   MAX   This conveniently-large knob adjusts the main mix   output level at the main outputs [6]. The meters will   also be affected by this control.   FireWire recording channels 1–4 only   It does not adjust the levels to your headphones,   FireWire outputs, or the aux outputs.   • If pressed in, the FireWire output to your   computer will be the mix of channels 1 to 4,   including any FireWire audio coming in from   your computer. This is a good position to record   live, where your complete main performance   (including any input from the computer) can   be recorded via FireWire.   1 2 3 4 U U LEVEL   O O   O O   MAX   MAX   FireWire input from computer   LOOP   OUT   O O   FW IN   MAX   PRESS IN TO MAKE THIS CONNECTION   FireWire recording channels 1–4 and FireWire in   19   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   Appendix A: Service Information   • If you are playing a guitar or other instrument level   source into channel 1, make sure you are using the   1/4" input, and that the instrument switch [11] is   engaged.   If you think your U.420d has a problem, please check   out the following troubleshooting tips and do your best   to confirm the problem. Visit the support section of our   website (www.mackie.com/support) where you will find   lots of useful information such as FAQs, documentation,   and user forums. You may find the answer to the prob-   lem without having to send your U.420d away.   • If you are playing a guitar into channel 2, 3, or 4,   you need to use a DI box for the correct impedance   match and high frequency fidelity.   These may sound obvious to you, but here are some   things you can check. Read on:   • • Try the same source signal in another channel, set   up exactly like the suspect channel.   Only phono-level sources (turntables) should be   connected to the RCA phono inputs [3]. The phono   section requires your cartridge to be a moving-mag-   net type. It may be too low to amplify the low levels   of a moving-coil type.   Troubleshooting   No Power   • Make sure the external power supply is securely   seated in the DC input [8] and plugged all the way   into the AC outlet.   • If there is no phono output, check that there is   nothing plugged into the channel’s line-level inputs.   The phono inputs are disconnected internally when   a 1/4" connector is plugged into the same channel.   • • • • Make sure the AC outlet is live (check with a tester   or lamp).   • • Only line-level sources should be connected to the   line-level inputs [2] of channels 3 and 4.   Is the power LED [28] illuminated? If not, make   sure the AC outlet is live.   If possible, listen to the signal with headphones   plugged into the input source device. If it sounds   bad there, it’s not the mixer causing the problem.   Are all the lights out in your town? If so, contact   your local power company to get power restored.   If no LEDs are illuminated, and you are certain   that the external power supply is working, it will be   necessary to have your mixer serviced. There are no   user serviceable parts inside. Refer to “Repair” on the   next page to find out how to proceed.   Bad Output   • • Is the associated level control (if any) turned up?   If a left output is presumed dead, switch the left   and right cords at the mixer end. If the problem   stays on the left side, it’s not the mixer.   Bad Channel   • Check the connections from your source are made   securely, and that the cords are in good condition.   Noise/Hum   • Check that your turntable’s audio ground wire is   connected to the ground terminals [4].   • Check the channel’s program gain [12] or [20] are   set correctly.   • Turn down each channel, one by one. If the noise   disappears, it’s coming from whatever is plugged   into that channel. Check your whatever.   • • Are that channel’s EQ controls all turned down?   Is the signal source turned up? Make sure the   signal level from the selected input source is high   enough to light the level set LEDs [10] when ad-   justed with the gain controls.   • Check the signal cables between the input sources   and the mixer. Disconnect them one by one. When   the noise goes away, you’ll know which input source   is causing the problem.   • • Sometimes it helps to plug all the audio equipment   into the same AC circuit so they share a common   ground.   Hungry? Try the all-you-can-eat lunchtime buffet at   the Bombay Palace in downtown Woodinville.   ꢀ0   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Repair   For warranty repair or replacement, refer to the war-   ranty information on page 31.   Non-warranty repair for Mackie products is available   at a factory-authorized service center. To locate your   nearest service center, 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 have access to our website, you can call   our Tech Support department at 1-800-898-3211,   Monday-Friday, 7 am to 5 pm Pacific Time, to explain the   problem. Tech Support will tell you where the nearest   factory-authorized service center is located in your area.   ꢀ1   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   Appendix B: Connections   XLR Connectors   1/4" TS Phone Plugs and Jacks   The mixer’s combo inputs accept 3-pin male XLR con-   nectors. These are wired as follows, according to stan-   “TS” stands for Tip-Sleeve, the two connection points   available on a mono 1/4 phone jack or plug. They are   " dards specified by the AES (Audio Engineering Society). used for unbalanced signals.   2 SHIELD   HOT   SLEEVE   SLEEVE   TIP   TIP   1 3 COLD   TIP   SHIELD   1 SLEEVE   3 COLD   2 1/4 TS Unbalanced Wiring:   " HOT   SHIELD   COLD   HOT   Sleeve = Shield   Tip = Hot (+)   1 3 2 XLR Balanced Wiring:   Pin 1 = Shield   Pin 2 = Hot (+)   Pin 3 = Cold (–)   RCA Plugs and 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. They are unbalanced and   1/4" TRS Phone Plugs and Jacks   electrically equivalent to a 1/4 TS phone plug.   " “TRS” stands for Tip-Ring-Sleeve, the three connection   TIP   SLEEVE TIP SLEEVE   points available on a stereo 1/4 or balanced phone   " jack or plug. TRS jacks and plugs are used for balanced   signals and stereo headphones:   RCA Unbalanced Wiring:   Sleeve = Shield   Tip = Hot (+)   Balanced Mono   RING SLEEVE   TIP   SLEEVE RING TIP   RING   TIP   SLEEVE   1/4 TRS Balanced Mono Wiring:   " Sleeve = Shield   Tip = Hot (+)   Ring = Cold (–)   Dimensions   Stereo Headphones   3.7 in/   94 mm   9.4 in/   239 mm   RING SLEEVE   TIP   SLEEVE RING TIP   RING   TIP   WEIGHT   3.0 lb   1.36 kg   SLEEVE   10.0 in/   254 mm   1/4 TRS Stereo Unbalanced Wiring:   " Sleeve = Shield   Tip = Left   Ring = Right   ꢀꢀ   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Appendix C: Technical Info   Input/Output Characteristics:   Input gain control range:   Specifications   Ch.1 and 2 input gain knob (XLR):   Ch.1 and 2 input gain knob (TRS):   Ch.1 and 2 level faders:   +3 dB to +50 dB   –22 dB to +25 dB   Off to +10 dB   Off to +10 dB   –14 to +14 dB   Off to +10 dB   Frequency Response (ꢀ0 Hz to ꢀ0 kHz) :   Mic input to any output, –20 dBu in, +30 dB gain, +10 dBu out:   +0/–0.5 dB   FireWire Input Level knob:   Ch.3 and 4 Input Gain knob:   Ch.3 and 4 Input Level knob:   Line input to any output:   +0/–0.5 dB   Phono input to any output:   FireWire Output to FireWire Input:   0.5 dB of RIAA EQ curve   +0/–0.5 dB   Output gain control range (measured with 100 kΩ):   Main Level knob:   Channel Aux knob:   Phones Level:   Off to +10 dB   Off to +10 dB   Off to +10 dB   Distortion (THD+N):   Main Outputs, 20 Hz to 20 kHz, 1 kHz input signal:   Input Impedance:   Mic Input:   Line Input:   Phono Input:   Mic input, –20 dBu in, +30 dB gain, +10 dBu out:   Better than 0.004%   Ch.1 and 2 line input at unity gain, +4 dBu input signal:   Better than 0.005%   1.7 kΩ balanced   50 kΩ balanced   47.5 kΩ shunted with 200 pF   Ch.3 and 4 line input at unity gain, +4 dBu input signal (via cross-   fader VCA to main outs):   Phono input at unity gain, –30 dBu input signal   (via crossfader VCA to main outs):   FireWire output to FireWire input:   Aux Outputs, 20 Hz to 20 kHz, 1 kHz input signal:   Better than 0.150%   Maximum Output Levels:   Main Out:   Aux Out:   Phones:   +15 dBu   +15 dBu   1.5 Vrms into 32Ω (70 mW)   Better than 0.150%   Better than 0.005%   Mic input, –20 dBu in, +30 dB gain, +10 dBu out:   Output Impedance:   Main Out:   Aux Out:   Phones:   Better than 0.004%   Ch.1 and 2 line input at unity gain, +4 dBu input signal:   Better than 0.005%   120 Ω   120 Ω   50 Ω   Ch.3 and 4 line input at unity gain, +4 dBu input signal (pre-cross-   fader VCA to aux outs):   Phono input at unity gain, –30 dBu input signal (pre-crossfader   VCA): Better than 0.030%   Phones output, 20 Hz to 20 kHz, +4 dBu input signal   Better than 0.005%   Equalization   Channels 1 and 2:   Low:   –15 dB to +15 dB @ 80 Hz   –15 dB to +15 dB   100 Hz to 8 kHz   Mid Level:   Mid Frequency:   High:   Ch.1 or 2 line input at unity gain:   Better than 0.015%   Common Mode Rejection Ratio   –15 dB to +15 dB @ 12 kHz   Channels 3 and 4:   Mic input, maximum gain, 1 kHz:   Better than 60 dB   Low:   Mid:   High:   Off to +10 dB @ 300 Hz   Off to +10 dB @ 1 kHz   Off to +10 dB @ 4 kHz   Attenuation/Crosstalk (1 kHz, ꢀ0 Hz to ꢀ0 kHz):   Channel Attenuation –Main level at unity gain, signal placed on any   channel with gain knob at unity and level knob or fader at minimum,   FireWire   Sample rates:   Main outs measured:   Better than –85 dBu   44.1 kHz, 48 kHz,   88.2 kHz, 96 kHz   Crosstalk –Main Level at unity gain, signal placed on any channel with   gain knob at unity and level knob at minimum, main outs measured   with any other channel gain knob at unity and level knob at unity:   Better than –85 dBu   Resolution:   24-bit   VU Meters   8-segment post Main Level meters:   Crossfader attenuation –Main level at unity gain, signal placed on chan-   nel 3 or 4, gain knob at unity, level knob at unity, crossfader moved to   OL (+13), +10, +7, +4, +0,   –4, –10, –20 dBu   opposite channel:   Better than –90 dBu   Level Set LED (Sensitivity):   0 dBu   Noise Characteristics:   Equivalent Input Noise (EIN), 20 Hz to 20 kHz, max gain:   AC Power Requirements:   Power Consumption:   8.9 watts   Mic input, 150 Ω source impedance:   Better than –125 dBu   Signal to Noise Ratio, 20 Hz to 20 kHz, ref +4 dBu:   Universal AC Power Supply:   100 VAC – 240 VAC,   50–60 Hz   Main Outputs: Main out at unity, all channel gain knobs at minimum:   Better than –90 dBu   Line: Main out at unity, all channel gain knobs at unity (dummy   plugs in Ch.3 and 4 TRS inputs so Phono is disengaged):   Better than –88 dB   Physical Dimensions and Weight:   Height: 10.0 in/254 mm   Width:   Depth:   9.4 in/239 mm   3.7 in/94 mm   Aux Outputs: All channel aux knobs at unity with all channel gain   knobs at unity (dummy plugs in Ch.3 and 4 TRS inputs so Phono is   Weight: 3.0 lb./1.36 kg   disengaged):   Better than –90 dB   Phono: Main Out at unity, Ch.1 and 2 at minimum, Ch.3 and 4 Phono   at unity gain (no TRS plugs in Channel 3 or 4):   Better than –74 dB   (See the lovely dimensions drawing on the previous page.)   LOUD Technologies Inc. is always striving to improve our products by   incorporating new and improved materials, components, and manu-   facturing methods. Therefore, we reserve the right to change these   specifications at any time without notice.   FireWire: Main Out at unity, all channel gain knobs at minimum,   FireWire input level at unity:   Better than –87 dB   Maximum Input Levels (rated at 1% THD):   “Mackie,” and the “Running Man” are registered trademarks of LOUD   Technologies Inc. All other brand names mentioned are trademarks   or registered trademarks of their respective holders, and are hereby   acknowledged.   Mic Inputs, preamp gain min (+3 dB):   Line Inputs, unity gain:   Phono Input:   +12 dBu   +15 dBu   77 mV rms @ 1 kHz   ꢀꢁ   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   R L R R L R E U C   X U A   E U C   X U A   L L R L R L N I A M   N I A M   ꢀ4   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   Appendix D: FireWire   System Requirements   FireWire stream to computer   These are the minimum requirements for your com-   puter system to use the U.420d FireWire interface.   In addition to a mix of channels 1 to 4, the FireWire   output to your computer can contain any FireWire input   from your computer, if the FW loop out switch [34] is   down.   For the PC:   • • • Windows XP (service pack 2)   Pentium 4 or Athlon XP processor   256 MB RAM   1 2 3 4 U U LEVEL   O O   O O   MAX   MAX   For the Mac:   FireWire input from computer   • • • OS X (10.3.9 or higher)   G4 processor   256 MB RAM   LOOP   OUT   O O   MAX   FW IN   PRESS IN TO MAKE THIS CONNECTION   The internal FireWire interface will allow the left and   right main mix to be recorded on a Mac or PC computer.   It also allows two channels of audio from the computer   to be added to the main mix.   The mains and phones outputs are not af-   fected by the switch, and always provide a   full mix of channels 1 to 4 and the 2-channel   FireWire input.   FireWire stream from computer   The analog audio from the mixer is converted to digi-   tal signals by the FireWire interface’s A/D converters.   The following table shows the outputs from your com-   puter to the mixer’s FireWire interface:   The following table shows the outputs to your com-   puter from the mixer’s FireWire interface:   From   To   To   From   Computer output 1 Main mix L   Computer output 2 Main mix R   Computer input 1 Left mix of channels 1 to 4   with FW input (switch down)   or without FW in (switch up)   The 2-channel digital stream from the computer   enters the mixer through the FireWire connector and is   converted to analog audio.   Computer input 2 Right mix of channels 1 to 4   with FW input (switch down)   or without FW in (switch up)   The audio level can be adjusted using the FW in   control [33].   Here are two examples of using the FW loop out   switch:   Beware of a possible feedback loop, if you are   feeding the main mix back into the mixer.   Studio Overdub – Tracktion playback is coming   into the mixer on FireWire inputs, and routing   through the mains/phones for you to hear. A   guitar plugged into channel 1 is being recorded   via the FireWire output, while you listen and   play along to the Tracktion playback. The FW   loop out switch is up, so the FireWire out-   put contains all playing channels except the   FireWire playback.   Live Performance – Computer playback software   like Ableton Live is being mixed to the mains   with other stereo sources such as synths, sam-   plers, turntables, and CD-DJ players. The FW   loop out switch is down, so everything will be   fed to the FireWire out for recording an entire   set.   ꢀ5   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   Direct hardware monitoring   Recording with FireWire   The U.420d’s built-in FireWire connection allows   overdub style recording to a Mac or PC digital audio   workstation (DAW) through the FireWire cable.   When in performance or “live set” recording   mode, many professional audio interfaces   go to significant lengths to simulate direct   hardware monitoring by incorporating a zero-latency   monitoring engine via dedicated digital signal process-   ing. This usually requires you to configure a separate   “virtual” mixer for monitoring. The U.420d ALWAYS   provides zero-latency monitoring by design, without any   extra configuration. Hurrah!   Here are some steps showing how to record a first   track, and then record additional tracks while monitor-   ing ones that have already been recorded.   1. Connect the sound source you wish to record to   your audio software, for example:   Due to the nature of its signal path, the U.420d re-   quires the use of direct hardware monitoring, as follows:   • • A microphone for a voice or instrument.   A line-level source such as an electronic   keyboard.   • Arm the track you wish to record onto, on your   DAW software.   • • A turntable connected to the phono inputs.   • On the track you have just armed, press that   track’s mute button, so that (while recording)   you do not hear the return of that track com-   ing from the computer. This will ensure you do   not mix the direct track you are monitoring,   with the duplicate of the track on the DAW as   it is being recorded. You do not want to hear   the direct and DAW track of the same source   simultaneously, as the DAW version might be   slightly delayed, and the combination of the two   will produce a filtered sound.   An instrument connected directly to the   instrument input 1 (with the instrument   switch [11] pressed in).   2. Make sure the FW loop out switch [34] is not   pressed in. This will ensure that during each   recording pass, the audio software only receives   the track-in-progress as an audio signal, and   not the pre-existing mix from the computer as   well.   3. Set the gain knob [12] at the top of the channel   you are using, to an appropriate level for the   source being recorded, using the level set LED   [10] as a guide. Once the gain has been set, set   the channel fader [19] to unity (0 dB).   • • Make sure that the DAW’s input meters show   a healthy level, and if it needs to be increased   or decreased, adjust the signal’s channel fader   [19], not the gain knob [12].   Press record on the DAW and record the track.   The signals going out to your computer are not   affected by the main volume knob [36] or the   phones knob [35].   Overdubbing   4. If you are recording an acoustic source through   a microphone, monitor it through headphones,   not through speakers. This will prevent sound   from the speakers from leaking into the micro-   phone. If working in this fashion, turn down the   main volume knob [36], and instead turn up   the phones knob [35] for safe listening levels in   the headphones.   To overdub additional tracks while listening to previ-   ously recorded ones, follow these steps:   • • • • Unmute the previously recorded track in the   DAW. It will now play out of the DAW’s main L-R   mix into the FW input of the mixer.   Set the level of the FireWire in knob [33]   to a level where you can hear the previously   recorded track comfortably.   Monitoring   Arm a new track in the DAW software and mute   that same DAW channel, and record the new   track on your DAW *.   When recording to computer software, there are two   ways to monitor the track you are recording:   While recording the new track, you will hear   the previously recorded tracks coming into the   mixer’s FireWire input, while you simultane-   ously hear the current track you are recording   directly through the mixer hardware.   1. Direct hardware monitoring: Listen to the track   you are recording directly off of your mixer,   while also listening to previously-recorded   tracks on your DAW software, as they are fed   back into the mixer.   • Repeat these steps until you have built up all   the tracks of your recording.   2. ”Through-the-DAW” monitoring, where you   monitor the track you are recording after its   round trip through the computer software,   along with any previously recorded tracks.   ꢀꢂ   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   * In Tracktion, it is not necessary to mute the output   of the track you are overdubbing on. Instead, select the   input to the track (it will be highlighted in red) and dis-   able the end-to-end function.   A word or three about latency   Latency describes the amount of time it takes the   input signal to pass through the system, and reach   the output. When recording a guitar and monitoring   through software, it is the amount of time it takes from   the moment you strike your guitar string, to the mo-   ment you hear it in your headphones. You are used to   this latency being very close to zero; when you play your   guitar through a guitar amp, you hear the signal imme-   diately. So when you are recording and monitoring via   software, you want this latency (delay time) to be as low   as possible.   You’ll hear existing tracks playing back via the   FireWire in, and you’ll be monitoring the track you are   recording through the U.420d’s headphones or main out.   When you play back the recording, you’ll hear the track   you’ve just overdubbed without un-muting anything.   We would like to set the latency as low as possible, but   the smaller it is, the harder the computer will have to   work. If the latency is very small, the computer needs to   work very hard to quickly transfer the audio in and out.   It may not even be able to keep up, especially if there   are lots of tracks, lots of automation and/or lots of plug-   ins in your work. If this happens, your audio may stop or   “drop out.” Drop outs may also occur if you have a slower   computer or not enough memory.   Other tips   • If recording with a microphone, turn down the   large volume knob [36] while recording, and   listen through the headphones instead.   When recording using the overdub method, it is   important to set the U.420d’s latency to it’s lowest oper-   able setting. This means going into the audio interface   property page of your recording program and setting the   latency property to the lowest setting the device and   your system will accept without any drop-outs, distor-   tion or CPU overburdening.   • If recording “direct” sources such as an electric   guitar or a turntable, you can listen with speak-   ers, as there is no microphone present to worry   about the speaker’s sound leaking in.   • One drawback of using direct hardware moni-   toring (vs. through-DAW monitoring) is that   the track you are recording will not normally   be able to take advantage of any effects that   the DAW’s mixer has to offer, such as a reverb   on the vocal being recorded, or a guitar amp   simulation on a directly attached instrument,   without introducing an unacceptable amount of   latency. One workaround is as follows:   The buffer is an area of computer memory that your   DAW uses to hold audio as it works. The smaller the   buffer, the faster audio gets in and out of your com-   puter, and the lower the latency. The size of the buffer   is measured in samples. Depending on your system, a   low setting is typically between 64 and 256 samples. The   more samples, the higher the latency time value. This   time value varies by sample rate, as shown in this table.   • • • • Set the latency on your DAW to as low as   the computer can handle, and check the   U.420d software console panel shows the   same value (see page 29 for more details).   Samples 44.1 kHz 48 kHz   96 kHz   0.7 ms   1.3 ms   2.7 ms   64   1.5 ms   2.9 ms   5.8 ms   1.3 ms   2.7 ms   5.3 ms   128   256   Do not mute the channel on the DAW that   is being recorded. This will allow you to   hear a mixture of the direct hardware   monitor, and the through-DAW signal.   It is generally accepted that delay or latency times of   3.3 ms or less, are tolerable for musical timing accuracy.   Apply the effect of choice (reverb, amp   emulation) to the DAW track, which you   will hear mixed in with the direct hardware   monitor source.   Higher latency settings are fine and even necessary   when in live record or performance mode. The same is   true for mix-down mode, especially when you start add-   ing lots of plug-ins.   As long as the latency is set low enough,   the timing difference between the direct   and through-DAW signal should be small   enough to not cause distraction.   ꢀ7   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   6. The next window reminds you to make sure the   U.420d is NOT connected to your computer yet.   Read the instructions and click “Continue.”   Software installation   For the PC:   When using the mixer with a PC, it is necessary to   first install the drivers and the control panel. The con-   trol panel allows you to set the sample rate and adjust   the latency of the audio passing through the mixer’s   FireWire interface. If you use a Macintosh computer,   please jump ahead to page 30.   The U.420d and U.420 share the same install-   er, so the screenshots say “U.420” even though   you have a U.420d. No worries.   7. You may get a warning about running the   installer because it hasn’t passed Windows   Logo testing. It’s okay. We’ve tested it and it is   compatible with Windows XP. Click “Continue   Anyway.”   Do not connect the mixer’s FireWire con-   nector to your computer just yet. We will   tell you when.   To install the software on a PC running   Windows XP (SPꢀ):   1. Turn off any (non-essential) applications.   2. Insert the U.420d 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.   8. Now it is time to connect your U.420d FireWire   connection to your computer. Follow the in-   structions and then click “Next.”   4. The Installer opens. Click “Continue.”   5. Next you will see the License Agreement. Read   through the text and if you are all in favor, click   “I Agree.”   ꢀ8   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   9. Wait until the “Found New Hardware Wizard”   pops up. Do not select any options, just click   “Cancel” to continue. If the same screen comes   back up, click “Cancel” again.   12. A window will pop up to let you know that the   installation was successful. Click “Finish.”   Now you are ready to use the FireWire capabili-   ties of your U.420d.   Do not worry about the various popup warnings,   even the one that says “a problem occurred..”   Pay no attention to the man behind the curtain.   Console (PC only)   You should adjust the sample rate and latency from   within your audio software application, for example in   Tracktion’s “settings” tab. If this is not an option in your   software, then use this console instead.   If you do this from within your software ap-   plication, do not use the control panel during   the same session, or there might be a conflict.   You can use the console for a quick check of the set-   tings, and to make sure they are the same as your audio   software settings.   10. You will get another impertinent warning, this   time about installing the hardware. It’s okay.   Click “Continue Anyway.”   The installer places a shortcut to the console   on your desktop.   • • Adjust the sample rate by clicking on the arrow   in the sample rate window. (The arrow disap-   pears if your local software has control.)   11. The drivers and control panel will be installed   on your computer.   Adjust the latency by clicking and moving the   slider in the display. (It looks like a crossfader,   but only adjusts the latency.)   ꢀ9   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   For the Mac:   Selecting the device (Mac/PC):   1. If you have followed the preceeding instruc-   tions for the PC or Mac, connect the U.420d to   your computer using the FireWire connection.   Macintosh OS X Audio MIDI Setup   (version 10.ꢁ.9 or later):   2. In your audio production software, such as   Tracktion, select the U.420d as your input and   output device. The screenshot below shows the   “Settings” area of Tracktion 3.   Macintosh OS X does not require FireWire drivers   to be installed. OS X provides a dedicated setup utility   for audio and MIDI. You can use the Audio MIDI Setup   utility to change the default audio input and output and   general system settings on your Macintosh.   1. Go to the Applications folder and open the   Utilities folder.   2. Double-click “Audio MIDI Setup.”   3. Play a source into the U.420d and verify that   your software is receiving the signals correctly.   4. Record audio and play it back to verifiy every-   thing is working nicely.   3. Click the Audio Devices tab, and select U.420 in   the “Properties For” drop-down box. Note that it   says U.420 and not U.420d, that’s all OK.   4. Here you can see the settings for the U.420d.   You can also choose it as your default input or   output, as well as designate it to be used for the   system sound output.   U U LEVEL   O O   O O   MAX   MAX   5. You’re ready to go with any Mac OS X Core   Audio host application (i.e., Tracktion, Logic,   Cubase, Nuendo, Live, Digital Performer, etc.).   DJ bunny!   ꢁ0   U.4ꢀ0d 4-Channel Mic/Line Mixer   Download from Www.Somanuals.com. All Manuals Search And Download.   U.420d Limited Warranty   Please keep your sales receipt in a safe place.   IMPORTANT: Make sure that the Service Request Number   is plainly written on the shipping carton. No receipt, no   warranty service.   A. LOUD Technologies Inc. warrants all materials,   workmanship and proper operation of this product for a period   of one year from the original date of purchase. You may   purchase an additional 24-month Extended Warranty (for a   total of 36 months of coverage). Visit our website and follow   If any defects are found in the materials or workmanship or   if the product fails to function properly during the applicable   warranty period, LOUD Technologies, at its option, will repair   or replace the product. This warranty applies only to equipment   sold and delivered within the U.S. and Canada by LOUD   Technologies Inc. or its authorized dealers.   E. LOUD Technologies reserves the right to inspect any   products that may be the subject of any warranty claims before   repair or replacement is carried out. LOUD Technologies may,   at our option, require proof of the original date of purchase in   the form of a dated copy of the original dealer’s invoice or sales   receipt. Final determination of warranty coverage lies solely   with LOUD Technologies.   F. Any products returned to one of the LOUD Technologies   factory-authorized service centers, and deemed eligible   for repair or replacement under the terms of this warranty   will be repaired or replaced. LOUD Technologies and its   authorized service centers may use refurbished parts for repair   or replacement of any product. Products returned to LOUD   Technologies that do not meet the terms of this Warranty   will not be repaired unless payment is received for labor,   materials, return freight, and insurance. Products repaired   under warranty will be returned freight prepaid by LOUD   Technologies to any location within the boundaries of the USA   or Canada.   B. For faster processing, register online at www.mackie.com,   or you may fill out and mail in the product registration card   included along with this manual.   C. Unauthorized service, repairs, or modification of Mackie   products will void this warranty. To obtain repairs or replacement   under warranty, you must have a copy of your sales receipt from   the authorized Mackie dealer where you purchased the product.   It is necessary to establish purchase date and determine whether   your Mackie product is within the warranty period.   D. To obtain warranty repair or replacement:   G. LOUD Technologies warrants all repairs performed   for 90 days or for the remainder of the warranty period.   This warranty does not extend to damage resulting from   improper installation, misuse, neglect or abuse, or to exterior   appearance. This warranty is recognized only if the inspection   seals and serial number on the unit have not been defaced or   removed.   1. Call Mackie Technical Support at 800/898-3211, 7 AM   to 5 PM Monday through Friday (Pacific Time) to get   authorization for repair or replacement. Alternately, go to   the Mackie website, click “Support” (www.mackie.com/   issue and submitting a request for an advance replacement.   2. Advance Replacement: Mackie will ship a replacement   unit to you along with an invoice for the suggested   retail price of the replacement unit. You must return the   defective unit immediately to cancel the invoice. If you do   not return the defective unit within 30 days, you must pay   the full amount stated in the invoice to satisfy your debt.   H. LOUD Technologies assumes no responsibility for the   timeliness of repairs performed by an authorized service   center.   I. This warranty is extended to the original purchaser. This   warranty may be transferred to anyone who may subsequently   purchase this product within the applicable warranty period   for a nominal fee. A copy of the original sales receipt is   required to obtain warranty repairs or replacement.   3. Repair: When you call Mackie Technical Support,   explain the problem and obtain a Service Request   Number. Have your Mackie product’s serial number   ready. You must have a Service Request Number before   you can obtain factory-authorized service.   J. This is your sole warranty. LOUD Technologies does not   authorize any third party, including any dealer or sales   representative, to assume any liability on behalf of LOUD   Technologies or to make any warranty for LOUD Technologies   Inc.   • Pack the product in its original shipping carton. Also   include a note explaining exactly how to duplicate the   problem, a copy of the sales receipt with price and date   showing, your daytime phone number and return street   address (no P.O. boxes or route numbers, please!), and   the Service Request Number. If we cannot duplicate the   problem or establish the starting date of your Limited   Warranty, we may, at our option, charge for service time   and parts.   K. THE WARRANTY GIVEN ON THIS PAGE IS THE SOLE   WARRANTY GIVEN BY LOUD TECHNOLOGIES INC.   AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS   AND IMPLIED, INCLUDING THE WARRANTIES OF   MERCHANTABILITY AND FITNESS FOR A PARTICULAR   PURPOSE. THE WARRANTY GIVEN ON THIS PAGE SHALL BE   STRICTLY LIMITED IN DURATION TO ONE YEAR FROM THE   DATE OF ORIGINAL PURCHASE FROM AN AUTHORIZED   MACKIE DEALER. UPON EXPIRATION OF THE APPLICABLE   WARRANTY PERIOD, LOUD TECHNOLOGIES INC. SHALL   HAVE NO FURTHER WARRANTY OBLIGATION OF ANY   KIND. LOUD TECHNOLOGIES INC. SHALL NOT BE LIABLE   FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL   DAMAGES THAT MAY RESULT FROM ANY DEFECT IN THE   MACKIE PRODUCT OR ANY WARRANTY CLAIM. Some states   do not allow exclusion or limitation of incidental, special, or   consequential damages or a limitation on how long warranties   last, so some of the above limitations and exclusions may not   apply to you. This warranty provides specific legal rights and   you may have other rights which vary from state to state.   • Ship the product in its original shipping carton,   freight prepaid to the authorized service center. Write   the Service Request Number in BIG PRINT on top of   the box. The address of your closest authorized service   center will be given to you by Technical Support, or it   may be obtained from our website. Once it’s repaired,   the authorized service center will ship it back by ground   shipping, pre-paid (if it qualified as a warranty repair).   Note: Under the terms of the warranty, you must ship   or drop-off the unit 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 unit to be considered for   warranty repair.   ꢁ1   Owner’s Manual   Download from Www.Somanuals.com. All Manuals Search And Download.   16220 Wood-Red 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: [email protected]   Download from Www.Somanuals.com. 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