YamahaメーカーPM4000の使用説明書/サービス説明書
ページ先へ移動 of 132
PROFESSIONAL AUDIO MIXING CONSOLE PM4000 OPERATING MANUAL YAMAHA.
PM4000 OPERATING MANUAL.
IMPORTANT NOTICE FOR THE UNITED KINGDOM Connecting the Plug and Cord WARNING : THIS APPARATUS MUST BE EARTHED IMPORTANT. The wires in this mains lead are coloured in accordance with the following code.
How to Use This Manual If you are an engineer or technician who is familiar with sound system design, much of this manual will serve as a review for you. The basic features are presented in the “BRIEF OPERATING INSTRUC- TIONS” section. Check this and the “SPECIFICA- TIONS” section, and you will see most of what you need to know.
Table of Contents Page Sect. Title Section 1. Introduction Section 2. Brief Operating Instructions 2-1 2.1 PM4000 Front Panel Features 2-1 2.1.1 The Standard Monaural Input Module 2-7 2.1.2 The Stereo Input Module 2-12 2.1.3 The Master Module (1 - 8) 2-17 2.
Page Sect. Title 6-16 6.15 Stereo Master to Matrix ST Bus: Pre or Post ST Master Fader 6-17 6.16 Installation of Optional Input Transformers 6-18 6.15 Hints on Circuitry For Remote Control of the VCA Masters and Mute Groups Section 7. Operating Notes and Hints 7-1 7.
Section 1 Introduction.
Section 1. Introduction The PM4000 is a professional audio mixing console with the kind of flexibility, performance and reliability for which Yamaha has earned a worldwide reputation. It picks up where the famous PM3000 left off, with still more functions, a higher level of performance, and a greater degree of versatility than ever before.
combined signal through a single bus, which is why full-length Group Master Faders are provided on the PM4000. However, when the VCA Master Faders are used, more than one VCA Master can combine to alter the level of a single input channel.
stereo master output. Cue replaces the signal in the headphones and the stereo cue XLR outputs with only those sources whose CUE switches are engaged. The CUE system has input priority so that the ope.
Section 2 Brief Operating Instruction.
This locking switch assigns the channel output directly to the stereo bus. An LED in the switch turns on when the signal is assigned to the stereo bus.
TOM POWER switch is on. An LED in the switch turns on when phantom power is being applied to the channel input connector. When both the Master and this switch are on, +48 volts is applied to both pins 2 & 3 of the channel input XLR connector for remote power- ing of condenser microphones.
1 ~ 20 kHz The outer concentric knob sweeps the EQ Fre- quency between 1,000 and 20,000 Hz. -15 ~ +15 dB The inner concentric knob adjusts the gain of the set frequency band by plus or minus 15 dB.
Figure 2-1b. PM4000 Standard Input Module (middle portion of module) NOTE: A signal processor (effects device) can be set up before it is needed, its levels adjusted using the always active INSERT OUT signal, and then the processor can be inserted on cue in the channel’s signal path by pressing this switch.
mixing buses, and the inner rotary control on the right serves to PAN that signal between the L & R sides of that stereo pair. When the send is set for dual mono mode, the inner rotary control on the left sets the LEVEL applied to the AUX ST L bus (i.
prevents the channel from being muted. Engag- ing this switch ensures the channel will always be on so long as the channel ON switch is also engaged. 25. FADER This long-throw fader sets the level applied to the 8 group mixing busses, and the stereo bus.
2.1.2. The Stereo Input Module The PM4000 comes with at least four stereo input modules, located in near the master section. More of these stereo modules can be ordered in lieu of the monaural input modules. Their position in the main- frame is completely interchangeable with the standard input modules (see Section 6 for details).
input is available at odd-numbered busses, and the right input at even numbered busses (and, of course, L&R in are available to the L&R stereo bus). In L position, the right input is deactivated, and the left input connector is available to all group busses and the L&R sides of the stereo bus.
This indicators measure signal from the XLRs or from the INSERT IN jacks, whichever are active, as well as after the equalizer. If necessary, use the PAD or decrease the GAIN setting to prevent the LEDs from remaining on any longer than momentarily; otherwise excessive distortion and insufficient fader travel will result.
NOTE: PM3000 users will notice there is no EQ CLIP indicator. Clipping at this stage can occur even though the input signal is not clipping, due to boost (gain) applied with the EQ circuitry. In the PM4000, clipping in the equalizer is detected and shown on the PEAK indicators [7S] adjacent to the GAIN controls.
iary mixing bus. When the switch is in the center (OFF) position, no signal is applied to the auxil- iary bus. NOTE: When the input signal select switch [2S] is set to stereo mode, then the left input signal can be assigned to odd-numbered aux busses, and the right input to even numbered busses.
20S . MT PRE (switch) and L, R (level meters) The channel level meters consist of two rows of 6 LEDs each that display the left and right signal levels from -20 dB u to +6 dBu, plus PEAK (3 dB below clipping). The meters normally indicate the level after the EQ and the channel fader.
Figure 2-3a. PM4000 Master Module (matrix section of module) 2.1.3 The Master Module (1 - 8) These eight modules are identical, except that each controls a differently-numbered set of Group Master, VCA Master and Matrix Output channels. MATRIX SECTION 28.
Figure 2-3b. PM4000 Master Module (aux send and group sections of module) 33. CUE (Matrix cue) Pressing this switch part-way down causes momentary contact; pressing it further locks it down.
GROUP SECTION 39. PAN (group to stereo bus) This pan control is operational only when the adjacent GROUP-TO-ST switch is engaged. It then pans the group signal between the left and right sides of the stereo mixing bus. The signal is derived after the group master fader.
Figure 2-3c. PM4000 Master Module (VCA master section of module) VCA SECTION 46. VCA MUTE Engaging this switch is the equivalent of setting the VCA master fader at maximum kill . The switch is illuminated when the master fader is muted. This affects all input channels assigned to the correspondingly numbered VCA group.
2.1.4 The Stereo Master Module This module controls the output of the stereo bus and the two aux stereo busses. Figure 2-4a. PM4000 Stereo Master Module (upper portion of module) 51. CUE (Aux 1 Stereo cue) Pressing this switch part-way down causes momentary contact; pressing it further locks it down.
52. ON (Aux 1Master On) Engaging this locking, illuminated switch turns on the Aux 1 master output. When the output is turned off, the feed to the VU meter is also off, although the signal may still be previewed with the adjacent CUE switch [51].
gether, or they can be operated completely independently if, for example, the stereo bus is used for two discrete mono mixes. 2.1.5 The TB (Talkback) Module 60. TB-TO-MON. B Engaging this switch assigns the Talkback signal to the Monitor B mix. An LED in the switch turns on when it is assigned.
Figure 2-5b. PM4000 TB Module (middle portion of module) oscillator when it is not actually in use. NOTE: Even though the oscillator may not be assigned to any busses, it is still possible that you would inadvert- ently select it when preparing to use the talkback feature, or that some signal could leak into busses (albeit at low levels).
supply with an A-B powered mic, in which case you should turn off the TB 48V Switch. corresponding switch here is illuminated. See the meter bridge description in Section 2.1.7 for additional details. 71. (TB INPUT) This XLR-3 connector accepts a low-Z microphone or a line level signal, depending on the settings of the controls below it.
2.1.6 The Monitor Module 77. SOLO MODE (switch) Figure 2-6a. PM4000 Monitor Module (upper portion of module) Page 2-22 This locking, red, illuminated switch flashes when engaged, indicating the console monitor system is set to the SOLO mode.
81. ON switch (Monitor B On) Engaging this switch applies the Monitor B signal to the Monitor B left and right output connectors. The switch is illuminated when the output is on.
90. PHONES (Level control) This 2-gang rotary control adjust the output level at both stereo PHONES output jacks. It affects any signals which may be fed to these outputs.
2.1.7 The Meter Bridge The PM4000 is equipped with 2 jumbo and 12 or 16 large, illuminated VU meters, depending on the size of the mainframe. Each meter has true VU ballistics to indicate approximate loudness, plus a red "PEAK" LED which responds to instantaneous levels that are beyond the scale of the meter.
96. II (Group/Matrix/Aux meters and indicators) 97. ST L, ST R (Stereo output meters) On 24 and 32 channel mainframes, these four meters monitor the correspondingly numbered busses, as described above in item [95].
2.2 PM4000 Rear Panel Features All XLR connectors and phone jacks are balanced. Outputs and patch points are +4 dBu level unless otherwise noted. Channel inputs, sub inputs, sub outputs, and primary outputs all rely upon XLR-3 type connectors wired Pin 2=high, Pin 3=low, Pin 1=ground.
STEREO INPUT MODLUE INPUT STRIPS Figure 2-8. PM4000 Rear Panels Stereo Channel Input Strip Figure 2-9. PM4000 Rear Panel: Cooling Fans and Lamp Connectors (2 shown) The PM4000 contains three or four cooling fans, depending on mainframe size, distributed across the rear panel.
109. GROUP SUB IN (1 - 8) These eight female XLR connectors apply signal directly to the group mixing busses (ahead of the Group Insert point and Group Master Faders). They are used for “chaining” another mixing console’s group outputs into this console, with this console serving as the master for both consoles.
118. GROUP INSERT 1-8 (IN, OUT) These phone jacks serve as a patch point for the signal from the correspondingly numbered group mixing bus. Nominal output and input level is +4 dBu (1.
122. AUX INSERT 1-8 (IN, OUT) These phone jacks serve as a patch point for the signal from the correspondingly numbered auxiliary mixing bus. They function identically to the insert points for the group mixing bus [118].
PIN Nº 1 2 3 4 5 6 7 8 9 10 11 12 CONNECTOR PINS (FEMALE) FUNCTION PIN Nº FUNCTION VCA EXT 1 13 MUTE EXT 3 VCAEXT 2 14 MUTE EXT 4 VCA EXT 3 15 MUTE EXT 5 VCA EXT 4 16 MUTE EXT 6 VCA EXT 5 17 MUTE EXT 7 VCA EXT 6 18 MUTE EXT 8 VCA EXT 7 19 GND VCA EXT 8 20 GND GND 21 GND NC 22 INPUT CUE EXT MUTE EXT 1 23 SOLO EXT MUTE EXT 2 24 GND Figure 2-13.
134. TB OUT This male XLR connector outputs signal from the talkback circuit when the TB OUT switch [64] is on. If that switch is OFF, this output is muted. Assuming the TB OUT switch is on, this output is derived from the talkback input XLR when the TALKBACK switch [74] is engaged.
2.4 The PW4000 Power Supply Figure 2-16. PW4000 Power Supply (Front and Rear Panels) 141. POWER This alternate-action switch turns on the AC input to the supply, and thereby provides the necessary output voltages to the console via the umbilical power cable.
144. DC OUTPUT (Umbilical Connector) This locking, multi-pin connector provides the necessary DC voltages from the PW4000 power supply to the PM4000 console. The cable must be connected correctly before attempting to operate the console. See Figure 2-17 for the pin assignments.
Section 3 Specifications.
Section 3. Specifications PM4000 Mixing Console General Specifications Total Harmonic Distortion <0.1% (THD+N) 20 Hz - 20 kHz @ +14 dBu, 600Ω (Master Output) <0.
VU Meters (0 VU = +4 dBu output) 24 or 32 channel consoles 40 or 48 channel consoles VU Meter Peak Indicators Phantom Power Dimensions (W x H x D) Weight 4 8 Channel 2086 x 346 x 1121 mm 4 0 Channel 1.
INPUT CHARACTERlSTlCS Connection PAD Gain Trim Actual load Impedance 0 CH IN 1 ~ [ch (*1) -70 30 ST CH IN 1 ~ 4ch 0 30 -20 SUB IN GROUP (1 ~ 8) STEREO (L, R) AUX (1 ~ 8) AUX ST1, 2 (L, R) CUE (L, R) M.
Dimensional Drawings PM4000 Console (all versions) Page 3-4.
Page 3-5.
Page 3-6 PM4000 Console Rear Profiles.
Module Block Diagrams (See back of the manual for overall system block diagram) Page 3-7.
Page 3-8.
Page 3-9.
Page 3-10.
Page 3-11.
Page 3-12.
Section 4 Installation Notes.
Section 4. Installation Notes 4.1 Planning An Installation Before installing the PM4000, it is worthwhile considering how it will be used, how it is going to be connected, and what is the best way to implement the installation. To begin with, there must be a surface upon which the console can be mounted.
voltmeter. It is also a good idea to use a special outlet tester that will also indicate reversed polarity, weak or missing neu- tral, and weak or missing ground connec- tions in the outlet. Test the power supply before connecting the umbilical cable to the console.
Figure 4-2. Testing a 2-wire AC Outlet and a 3-Prong to 2-Prong Adaptor 4.2. 4 Improperly Wired AC Outlets: Lifted Grounds A "lifted ground" condition exists if the ground or If you detect a.
way to ground via the safety ground, instead of via a person’s body. When checking AC power lines at the outlet, be sure you have proper testing tools and some familiarity with the danger of shock hazards from AC power. Follow the dia- gram shown here, being careful not to touch metal with your hands.
4.3 Theory of Grouding Grounding is an area of “black magic” for many sound technicians and engineers, and certainly for most casual users of sound systems.
Dangerous potential differences can also occur without such shorts. Two individual localized ground points, if they are not directly connected, cannot be assumed to be at the same potential – far from it, in fact.
ment. If one of these conditions is not met, then instead of going directly to earth ground and disappearing, these circulating ground loop noise currents (which act like signals) travel along paths that are not intended to carry signals.
are required to implement this approach, since ground is not carried between components. One drawback is that cables may not all be the same – some having shields carried through at both ends, and others not, depending on the equipment – so it becomes more complicated to sort out the cabling upon setup and breakdown of a portable system.
end without affecting the audio signal on the two inner conductors of the cable, and with little or no effect on the shielding. Unfortunately, this is not a very practical solution to the ground loop problem for portable sound systems because it requires special cables with shields disconnected on one end.
The PM4000 is fitted with only two types of audio connectors: 3-pin XLRs, both male and female, and 3- circuit (tip/ring/sleeve) ¼” phone jacks (also known as stereo phone jacks, although their function is sometimes to carry a balanced mono signal rather than a stereo signal).
Figure 4-12. Cables For Use With Unbalanced Sources NOTE regarding Figure 4-12. For microphone cables, conect the shield to pin 1 at both ends of the XLR cable.
Figure 4-13. Cables For Use With Balanced Sources Page 4-12.
designed to recognize only the difference in voltage between the two wires, and (hence the term “balanced differential input”). Should any electrostatic interfer- ence or noise cut across a balanced cable, the noise voltage will appear equally - with the same polarity - on both signal-carrying wires.
where a transformer is desirable even if the input is electronically balanced. For example, where there is a signiftcant amount of electrostatic or electromagneti- cally induced noise, particularly hi.
4.5 Direct Boxes The so-called “direct box” is a device one uses to overcome several of the problems that occur when connecting electric guitars and some electronic key- boards to a mixing console.
which is ideal. Each winding, each Faraday shield, and the transformer chassis shield should have separate leads. Figure 4-15. Passive Musical Instrument Direct Box (D.I. Box) Schematic Diagram Notes Regarding Figure 4-15: 1. C1 is a high quality, non-polar aluminum electro- lytic, such as Roederstein type EKU.
4.5.2 Active Guitar Direct Box The active direct box shown here can be used at the output of a standard electric guitar, with or without an amplifier. Because of its very high input impedance, it can be used with a piezoelectric instrument pickup, taking the place of the preamp that is normally in- cluded with such pickups.
Before actually mounting the selected components, it is wise to carefully plan out each rack with an eye to signal flow, heat flow, and weight distribution. It might be best to mount together components that function as a group: the equalizer, active crossover and power ampli- fier for a single loudspeaker or array, for example .
SECTION 5 Gain Structure and Levels.
SECTION 5. GAIN STRUCTURE AND LEVELS Page 5-1 5.1 STANDARD OPERATING LEVELS There are a number of different “standard” operating levels in audio circuitry. It is often awkward to refer to a specific level (i.e., +4 dBu) when one merely wishes to describe a general sensitivity range.
5.2 Dynamic Range and Headroom 5.2.1 What Is Dynamic Range? Every sound system has an inherent noise floor, which is the residual electronic noise in the system equipment (and/or the acoustic noise in the local envi- ronment). The dynamic range of a system is equal to the difference between the peak output level of the system and the noise floor.
Figure 5-1. Dynamic Range and Headroom in Sound Systems Page 5-3.
5.2. 5 A General Approach To Setting Levels In a Sound System Just because individual pieces of sound equipment are listed as having certain headroom or noise and maximum output capability, there is no assurance that the sound system assembled from these components will yield performance anywhere near as good as that of the least capable component.
Remember that with a 20 dB headroom figure, a power amplifier as powerful as 500 watts will operate at an average 5 watts output power. In some systems such as studio monitoring, where fidelity and fu.
dynamic range. Of course, another alternative is available: add more amplifiers and speakers so that the 5.3 Gain Overlap And Headroom desired headroom can be obtained while raising the As explained previously, the PM4000 can deliver average power level.
Section 6 Optional Functions.
Section 6. Optiona l Functions The PM4000 is factory wired to suit what Yamaha engineers believe to be the greatest number of applica- tions. Yamaha recognizes, however, that there are certain functions which must be altered for certain specific applications.
6.1 Removing and Installing A Module Figure 6-1. Removal of PM4000 Module 1. Turn the Power OFF first, before removing or installing a module. 2. Loosen the screws at the top and bottom of the rear panel input/output strip corresponding to the module being removed (except Master section modules).
6.2 Mono Input Direct Out Jack: Pre-Fader or Post-Fader (switch) Pre-ON or Post-ON Switch (jumper) A slide switch in each input module permits the Direct Out point to be altered.
6.3 Mono Input Aux Sends: Pre Fader & EQ or Pre Fader/post EQ Ten slide switches in each input module permit each of the eight mono auxiliary sends and the two stereo aux sends to be altered.
6.4 Mono Input Cue/Solo Switch: Pre- Fader or Follow MT PRE Switch so that the take-off point for the cue/solo signal tracks the signal feed to the channel’s LED level meter.
6.5 Stereo Input Cue/Solo Switch: Pre- Fader or Follow MT PRE Switch so that the take-off point for the cue/solo signal tracks the signal feed to the channel's LED level meter.
6.6 Mono & Stereo Input Channel MT POST mode, the meter indicates the level after the PRE Switch: Pre- or Post-ON Switch Fader and the channel ON switch.
6.7 Stereo Input Channel Insert In/Out for example, when one wishes to the send to the signal Jacks: Pre-EQ or Post-EQ processor... for example, to apply the boost prior to compression. However, sometimes one wishes to equal- Four jumpers in each stereo input module permit the two pair of Insert In/Out points to be altered separately.
6.8 Stereo Input Channel Aux Sends: switch is set to PRE position, the aux send is derived Pre Fader & EQ or ahead of the the fader and equalizer (but after the high Pre Fader/Post EQ pass filter).
6.9 Stereo Input Channel Aux Sends 1-8: L+R Blend or Stereo Pairs and right inputs to the channel. Moving the switch changes the signal take-off points so that the odd- numbered Aux Sends derive signa.
6.10 Stereo Input Channel Stereo Aux Aux Sends each carry discrete left and right signals Sends 1 & 2: L+R Blend or Stereo from the channel input. Moving the switch changes the signal take-off poi.
6.11 Stereo Input Channel Feed to Determination of which stereo modules actually Monitor Module ST IN 3 or ST IN 4 contribute to the monitors when the monitor module’s ST IN3 or ST IN4 switch is eng.
6.12 Phase Switch Function: Change Polarity of Both L and R inputs, or of L Only As shipped, the Stereo Input Module’s Phase Swich (Ø) [8S], which is really a polarity switch, reverses the polarity of both the left and right inputs to the module.
6.13 Stereo Input Module: Output Enable Jumpers to Group, Stereo and Aux Busses The stereo input module may be used as an effects return module. In this case, it could be disastrous if an incoming signal were to be assigned to the bus which is feeding the signal processor whose output is coming into the module.
6.14 Master Module: Group-to-Matrix Assigned Pre or Post Group Master Fader stereo house mix from the eight subgroups, yet you need as many as eight additional mono or five stereo mixes. The mix matrix alone allows for only one stereo and A slide switch in each master module permits the module’s group send to the mix matrix to be altered.
6.15 Stereo Master to Matrix ST Bus: Pre or Post ST Master Fader A slide switch in Stereo Master module enables the signal applied to the matrix stereo bus from that module to be derived from two different points.
6.16 Installation of Optional Input Transformers The PM4000 standard input module is equipped with a balanced, differential input preamplifier for the XLR connector.
6.15 Hints on Circuitry For Remote Control of the VCA Masters and Mute Groups The VCA/MUTE CONTROL connector on the PM4000 rear panel is provided primarily so that two consoles may be linked, and just one console’s VCA MASTER FADERS and/or MUTE MASTER switches will affect both consoles input channels.
YAMAHA SUFFIX VALUE OR PART# QUAN ITE M LETTER TYPE UA21410 2 K MYLAR CAPACITOR 0.01 uF, 50 V HU07543 1 F METALIZED FILM RESISTOR 430 ohm, ¼ W HU07610 4 F METALIZED FILM RESISTOR 1 kohm, ¼ W HU07620.
Section 7 Operating Notes and Hints.
Section 7. Operating Notes and Hints This section is not meant to be comprehensive. Instead, it focuses on a few areas which we feel require special attention, or where a better understanding of the function can lead to far more utility or better sound quality from the PM4000.
Given the correct GAIN and PAD settings, adjust the channel Fader to its nominal (0 dB) setting. This setting provides the best range of control, with some boost available if the signal must be raised in the mix, and plenty of resolution for fading the signal down in the mix.
Fader, which is changeable via internal preset switches; the Group bus calibration must still be done first to establish the proper levels on the group busses ahead of the Group Masters.
7.1.9 Channel Muting and Gain Structure As pointed out earlier, adding inputs to a mix will increase mix levels. If optimum mix levels are estab- lished with some input channels muted, and those chann.
trolled Amplifier) in the input module. The audio signal flowing through that VCA is, in turn, increased or decreased in level according to the control voltage applied to the VCA. One advantage of the VCA is that the control voltage applied to it can come from more than one point.
NOTE: Channels and outputs are selected at random in this illustration. The VCA Master Fader controls multiple input channels, and their outputs to all bus- ses (assuming Post-fader AUX sends). There is no single insert IN/OUT point that can process this VCA-controlled group of inputs, however.
On the other hand, if one “pulls down” the conven- tional Group Master Fader in the first example above, the level of the double-assigned input will only drop 3 dB, whereas pulling down a VCA Master Fader will completely kill any input channel assigned to that VCA group.
The Mix Matrix is Located on the Top portion of Master Modules 1-8 Figure 7-3. Front Panel View and Block Diagram of PM4000 Mix Matrix Page 7-8.
7.2.4.1 The Mix Matrix In General Sound Reinforcement Instead of feeding the house sound system directly from the Group outputs [130], or the Stereo output [133], the sound system can be fed from the Matrix outputs [131]. The Group busses and Stereo bus would then be used for mixing sub-groups of different sources; i.
into the corresponding matrix channels, and fed to the house sound system which is driven by the matrix outputs. A related use for the MTRX SUB IN connectors is to inject a test signal for speaker setup and testing.
moment the choir is called upon, thus reducing noise, the “hollow” sound from those open mics, and removing the extra stress on the choir members of having to keep absolutely still during the entire service. These are but a few of the ways that the PM4000’s ability to mute overlapping groups of input channels can be used to advantage.
7.2.6 Stereo Panning To the Eight Group Mixing Busses The input channel bus assignment is very flexible. One can assign a channel directly to the stereo bus using the ST switch [3], and the PAN pot will place the signal between the left and right sides of that stereo bus.
Section 8 Applications.
Section 8. Applications 8.1 General The PM4000 is designed primarily for audio mixing in live sound reinforcement applications. Its exceptional flexibility, however, will undoubtedly appeal to those w.
maintain an ideal S/N ratio while avoiding tape satura- tion. At the same time, the mix matrix can create working mixes of those groups, with levels adjusted for more “listenable” reference monitoring or foldback.
With eight auxiliary sends, and four aux returns, it’s easy to utilize the most sophisticated effects. The aux returns, which can each be used for a mono or stereo source, have two-band, sweep-frequency equalization.
8.2.2 The Mix Matrix Allows the 8 Groups Plus the Stereo Bus to Function as 10 Subgroups. It is relatively straightforward to use the mix matrix to create up to eight mono outputs or four stereo out- puts from the eight subgroups and the stereo bus.
Figure 8-3. System Diagram For 5 Independent Stereo Output Mixes via the Stereo Bus and the Mix Matrix Page 8-5.
8.2.4 How to Use the VCA Masters Plus the Group Master Faders to Obtain the Functional Equivalent of 16 Subgroups. Let’s assume the object is to obtain a stereo output (or a pair of mono outputs). Some input channels can be assigned to the Group busses via their assign switches [1].
8.2.5 Using More Than One VCA Master to Control the Same Input Channels In Order To Handle Overlapping Scenes. In a multi-scene theatrical presentation, or a multi- set concert, to name a couple of examples, it may be necessary to mix the same input channels at different levels to suit changing stage requirements.
Section 9 Maintenance.
Section 9. Maintenance 9.1 Cleaning The Console 9.1.1 The Console and Power Supply Exterior The console and power supply are painted with a durable finish. To avoid damage to the paint, control knobs, switch caps and other parts, DO NOT USE SOLVENTS. Instead, keep the console as free of dust as practical.
9.2 Meter Lamp Replacement The VU meters and meter-assign indicators are illuminated by LEDs which should not require replace- ment. Contact your Yamaha dealer or service facility should a meter illumination LED fail.
9.4 What To Do In Case of Trouble The PM4000 is supported by Yamaha’s worldwide network of factory trained and qualified dealer service personnel. In the event of a problem, contact your nearest Yamaha PM4000 dealer. For the name of the nearest dealer, contact one of the Yamaha offices listed below.
.
YAMAHA VN02300.
デバイスYamaha PM4000の購入後に（又は購入する前であっても）重要なポイントは、説明書をよく読むことです。その単純な理由はいくつかあります：
Yamaha PM4000をまだ購入していないなら、この製品の基本情報を理解する良い機会です。まずは上にある説明書の最初のページをご覧ください。そこにはYamaha PM4000の技術情報の概要が記載されているはずです。デバイスがあなたのニーズを満たすかどうかは、ここで確認しましょう。Yamaha PM4000の取扱説明書の次のページをよく読むことにより、製品の全機能やその取り扱いに関する情報を知ることができます。Yamaha PM4000で得られた情報は、きっとあなたの購入の決断を手助けしてくれることでしょう。
Yamaha PM4000を既にお持ちだが、まだ読んでいない場合は、上記の理由によりそれを行うべきです。そうすることにより機能を適切に使用しているか、又はYamaha PM4000の不適切な取り扱いによりその寿命を短くする危険を犯していないかどうかを知ることができます。
ですが、ユーザガイドが果たす重要な役割の一つは、Yamaha PM4000に関する問題の解決を支援することです。そこにはほとんどの場合、トラブルシューティング、すなわちYamaha PM4000デバイスで最もよく起こりうる故障・不良とそれらの対処法についてのアドバイスを見つけることができるはずです。たとえ問題を解決できなかった場合でも、説明書にはカスタマー・サービスセンター又は最寄りのサービスセンターへの問い合わせ先等、次の対処法についての指示があるはずです。
