INSTRUCTION MANUAL POWERED MIXER MX-628 Please follow the instructions in this manual to obtain the optimum results from this unit. We also recommend that you keep this manual handy for future reference.
TABLE OF CONTENTS 1. SAFETY PRECAUTIONS... 3 2. GENERAL DESCRIPTION... 4 3. FEATURES... 4 4. NOMENCLATURE AND FUNCTIONS Operation Panel Channel control section... 5 Master output control section... 6 Output level indicator section... 6 Input and Output Panels Input panel section... 7 Output panel section... 8 5. CONNECTION EXAMPLE... 9 6. WIRELESS TUNER INSTALLATION... 10 7. CONNECTED EQUIPMENT SELECTION... 11 8. PROPER SOUND MIXING... 12 9. BLOCK/LEVEL DIAGRAM... 13 10. CHARACTERISTIC DIAGRAM... 14 11. DIMENSIONAL DIAGRAM... 14 12. SPECIFICATIONS... 15 2
1. SAFETY PRECAUTIONS Be sure to read the instructions in this section carefully before use. Make sure to observe the instructions in this manual as the conventions of safety symbols and messages regarded as very important precautions are included. We also recommend you keep this instruction manual handy for future reference. Safety Symbol and Message Conventions Safety symbols and messages described below are used in this manual to prevent bodily injury and property damage which could result from mishandling. Before operating your product, read this manual first and understand the safety symbols and messages so you are thoroughly aware of the potential safety hazards. WARNING CAUTION Indicates a potentially hazardous situation which, if mishandled, could result in death or serious personal injury. Indicates a potentially hazardous situation which, if mishandled, could result in moderate or minor personal injury, and/or property damage. WARNING When Installing the Unit Do not expose the unit to rain or an environment where it may be splashed by water or other liquids, as doing so may result in fire or electric shock. Use the unit only with the voltage specified on the unit. Using a voltage higher than that which is specified may result in fire or electric shock. Do not cut, kink, otherwise damage nor modify the power supply cord. In addition, avoid using the power cord in close proximity to heaters, and never place heavy objects -- including the unit itself -- on the power cord, as doing so may result in fire or electric shock. Avoid installing or mounting the unit in unstable locations, such as on a rickety table or a slanted surface. Doing so may result in the unit falling down and causing personal injury and/or property damage. When the Unit is in Use Should the following irregularity be found during use, immediately switch off the power, disconnect the power supply plug from the AC outlet and contact your nearest TOA dealer. Make no further attempt to operate the unit in this condition as this may cause fire or electric shock. If you detect smoke or a strange smell coming from the unit. If the unit falls, or the unit case breaks If the power supply cord is damaged (exposure of the core, disconnection, etc.) If it is malfunctioning (no tone sounds.) To prevent a fire or electric shock, never open nor remove the unit case as there are high voltage components inside the unit. Refer all servicing to your nearest TOA dealer. Do not place cups, bowls, or other containers of liquid or metallic objects on top of the unit. If they accidentally spill into the unit, this may cause a fire or electric shock. Do not insert nor drop metallic objects or flammable materials in the ventilation slots of the unit's cover, as this may result in fire or electric shock. Do not touch a plug or antenna during thunder and lightning, as this may result in electric shock. CAUTION When Installing the Unit Never plug in nor remove the power supply plug with wet hands, as doing so may cause electric shock. When unplugging the power supply cord, be sure to grasp the power supply plug; never pull on the cord itself. Operating the unit with a damaged power supply cord may cause a fire or electric shock. When moving the unit, be sure to remove its power supply cord from the wall outlet. Moving the unit with the power cord connected to the outlet may cause damage to the power cord, resulting in fire or electric shock. When removing the power cord, be sure to hold its plug to pull. Do not block the ventilation slots in the unit's cover. Doing so may cause heat to build up inside the unit and result in fire. 3
CAUTION Avoid installing the unit in humid or dusty locations, in locations exposed to the direct sunlight, near the heaters, or in locations generating sooty smoke or steam as doing otherwise may result in fire or electric shock. When the Unit is in Use Make sure that the volume control is set to minimum position before power is switched on. Loud noise produced at high volume when power is switched on can impair hearing. Do not operate the unit for an extended period of time with the sound distorting. This is an indication of a malfunction, which in turn can cause heat to generate and result in a fire. If dust accumulates on the power supply plug or in the wall AC outlet, a fire may result. Clean it periodically. In addition, insert the plug in the wall outlet securely. Switch off the power, and unplug the power supply plug from the AC outlet for safety purposes when cleaning or leaving the unit unused for 10 days or more. A fire or electric shock may result. 2. GENERAL DESCRIPTION TOA's MX-628 Powered Mixer is small in size, and comes with 8-channel inputs, 1-channel line output L and R, 1 foldback output and 1 effector output. It also has 2 channels (Speaker output L and R) of built-in power amplifiers with rated output power of 60 W (4 Ω). Its ideal applications include hotel banquet rooms. 3. FEATURES Each of Microphone Input Terminals 1 4 has a combination type of receptacle that permits connection of either the XLR connector or phone plug. Input Channels 5 and 6 can be used for wireless microphones when an optional diversity wireless tuner is installed in the unit. Auxiliary stereo Input Channels 7 and 8 are convenient for playback of stereo sound tapes or compact disks. Input Channels 1 6 are equipped with a trim control that permits even high level input signals to be mixed without distorting the output of the head amplifier. Equipped with line output L and R convenient for power amplifier expansion. 4
4. NOMENCLATURE AND FUNCTIONS [Operation Panel] Channel control section Output level indicator section Master output control section Wireless tuner receptacle (Channel 5) Wireless tuner receptacle (Channel 6) Channel control section Adjusts a trim, and the output level of panning potentiometer, sound volume, effector, and foldback of each channel. 7 1 2 3 4 5 6 1. Trim Control [TRIM] Adjusts the amplifier gain depending on the microphone input level. The gain increases as the control is rotated clockwise, and decreases as the control is rotated counterclockwise. The Trim Control handles the microphone level ranging from 66 db to 30 db. When the microphone input is distorted, rotate the control counterclockwise till the distortion is eliminated. The AUX Input is not equipped with the Trim Control. 2. Foldback Control [FB] Adjusts the level of a signal to be sent out from each channel to the Foldback Output. The foldback output is not influenced by the Microphone Input and AUX Input Level Control settings. 3. Effector Output Control [EFF] Adjusts the level of a signal to be sent out from each channel to the Effector Output. The Microphone Effector Output is influenced by the settings of both the Effector Output Control and Level Control. It is highly recommended that the Microphone Effector Output Control be adjusted after each channel's Level Control has been set. The AUX Effector Output is not influenced by the AUX input Level Control setting. 5
4. Pan-pot [PAN] Adjusts proportion of a microphone input signal to be assigned to both the L and R channels. Rotating the knob clockwise enhances R channel, and rotating the knob counterclockwise enhances L channel. 5. Balance Control [BAL] Adjusts the stereo balance of the AUX input signal. Rotating the control clockwise enhances R channel, and rotating the control counterclockwise enhances L channel. 9. Master Control [MASTER] Adjusts each output master level. Recording output is not influenced by the Master Control setting. Output level indicator section 10 11 6. Level Control [LEVEL] Adjusts each channel's output level. 7. RF Indicator [RF] This indicator is provided on Microphone Inputs 5 and 6, and lights when the optional wireless tuner installed in the unit receives a radio signal. Even if the wired microphone is connected to Microphone Inputs 5 and 6, the indicator lights when the wireless tuner receives a radio signal. However, the signal received by the wireless tuner is cut off. Master output control section 8 9 12 10. Power Indicator [POWER] Remains lit while the power is supplied to the unit. 11. Protection Indicator [PROTECT] The speaker output is cut off by means of an internal relay while this indicator is on. The Protection Indicator lights for approximately 5 seconds after the power has been switched on because the speaker output is cut off. However, this is not a unit failure. 12. Level Meter Indicates levels of the Speaker Output, Line Output, Foldback Output and Effector Output. When the "+6" indicator lights, this indicates the possibility of output signal distortion. In such cases, adjust the level with the Master Control [MASTER] so that the "+6" indicator does not light. 8. Equalizer [TREBLE/BASS] Adjusts high and low frequencies of a speaker output, recording output and line output signal. The center knob position provides flat frequency characteristics. Frequencies are boosted when the knob is rotated clockwise, and are cut when rotated counterclockwise. TREBLE: 10 khz ±10 db BASS: 100 Hz ±10 db 6
[Input and Output Panels] 20 19 18 17 16 15 14 13 20 Output panel section Input panel section 26 25 24 23 22 21 Input panel section 13. Microphone Input Terminals 1 6 [MIC1 MIC6] (XLR-3-31/its equivalent or phone jack) Input terminals 1 6 are connected to the unit's channels 1 6, respectively. These terminals permit connection of various sound sources ranging from microphones to line-signal level equipment depending on the Trim Control setting, and can be used for both balanced and unbalanced connections. Use a phone plug or XLR3-12C connector or its equivalent when connecting MIC1 MIC4 inputs, and a phone plug when connecting MIC5 and MIC6. As to their pin polarities, refer to the figures below and on the right. Wireless microphones can be used on channels MIC5 and MIC6 by installing an optional wireless tuner in the unit. It is impossible to simultaneously use both the wired and wireless microphones on the same channel. When the wired microphone is connected to channel MIC5 or MIC6, the wireless microphone signal to that channel is cut off. Connection plug pin polarity XLR3-12C or its equivalent Phone plug (balanced type) GROUND COLD Phone plug (unbalanced type) GROUND HOT HOT 14. Aux Input Terminals 1 and 2 [AUX1/AUX2] Connect to the unit's Channels 7 and 8, respectively. The input is of unbalanced type, and connects to a pin plug. Terminal 2 can be converted to Effector Input Terminal by means of the AUX2/EFF IN Selector Switch. Channels 7 and 8 are equipped with no trim control. Therefore, adjust the output level control of equipment connected to Channels 7 and 8 when a signal is distorted. Pin 1: GROUND Pin 2: HOT Pin 3: COLD 7
15. AUX2/EFF IN Selector Switch Sets Channel 8 for AUX2 or Effector Input. Shift the Switch closer to the AUX2 Terminal to select AUX2 Input, and to the Effector Terminal to select Effector Input. When using an effect sound device, be sure to shift the AUX2/EFF IN switch to the Effector Terminal side, and connect the effector's final output to the Effector Input Terminal. If connected to the AUX Input Terminal, the effector will not work properly and in addition, the unit could oscillate. 16. Effector Input Terminal [EFF IN] Connects to Channel 8 when the AUX2/EFF IN Selector Switch is set to the Effector Input Terminal side. The input is of stereo unbalanced type, and connects to a phone plug. Channels 7 and 8 are equipped with no trim control. Therefore, decrease the output level control of equipment connected to Channels 7 and 8 to avoid signal distortion. 17. Recording Output Terminal [REC OUT] Outputs mixed signals of each input individually for L and R channels. This output is not influenced by the Master Control setting. 18. Foldback Output Terminal [FB OUT] Output terminals for foldback signals. 19. Effector Output Terminal [EFF OUT] Connects to a reverb or other external effectors. Output panel section 21. Line Output Terminal [LINE OUT] Used to expand power amplifiers in such a case of high-impedance speaker connection for an example. This output is influenced by the Master Control setting. 22. Speaker Output Terminal [SPEAKER] Connects to the speaker. Connect the speaker so that the total impedance of L and R channels is 4 16 Ω each. 23. Power Switch [POWER] Switches on or off the unit's power. CAUTION Be sure to set the volume control to the minimum position before switching on the unit's power. Failure to do this could impair your hearing sensation because a big sound is suddenly output when the power is switched on. 24. Grounding Terminal [SIGNAL GND] This terminal is for signal grounding. 25. Voltage Selector (MX-628 LH only) Sets the selector to either 115 V or 230 V depending on your local power source. 26. AC Inlet Connect the supplied AC power cord to this inlet. 20. Antenna Terminal [ANT A/ANT B] Connect an optional wireless system antenna to this terminal when using an optional wireless tuner. 8
5. CONNECTION EXAMPLE Effector (reverb, etc.) Recorder (cassette deck, etc.) Power amplifier IN OUT IN IN Wireless system antenna Speaker (for foldback) Wireless system antenna OUT Speaker AC mains Sound source (CD player, etc.) Power amplifier Speaker IN Dynamic microphone Power amplifier Line output is influenced by the Master Control. IN Speaker (4 16 Ω each) Wireless microphone (Can be used only when a wireless tuner is installed in the unit.) Install the unit in well-ventilated locations. Do not block the unit's ventilation openings nor use the unit in a box. In addition, keep over 1 m space above the unit. 9
6. WIRELESS TUNER INSTALLATION By installing an optional wireless tuner in the unit, wireless microphones can be used. Prepare the wireless tuner, antenna, and slotted screwdriver, and follow the procedures below for installation. : Neither the WTU-870 unit nor the WTU-840 unit can be used. If used, the MX-628 may fail. Step 1. Place the unit's Power Switch in the OFF position. Step 2. Remove the wireless tuner receptacle cover on the front panel by inserting a slotted screwdriver in the gap and prying out the cover in the arrow direction as illustrated. Step 3. Check to confirm the channel to be used for the wireless microphone and the tuner's correct orientation, and then fully insert the tuner. (The illustration assumes that the tuner is inserted in Channel 5.) Step 4. Replace the cover by first inserting the arrow 1 section, and then pushing the arrow 2 section onto the tuner receptacle. 2 Tuner receptacle 1 Cover Step 5. Connect the optional antenna to the unit's antenna terminal. Antenna terminal Antenna terminal WARNING Never insert the slotted screwdriver or metallic objects in the ventilation slots, as this may result in fire or electric shock. 10
7. CONNECTED EQUIPMENT SELECTION Bear the following points in mind when selecting external equipment to be connected to the unit. the impedances of the unit and external equipment. It is generally said that by making the output impedance of signal transmitting equipment equal to the input impedance of signal receiving equipment (impedance matching) or by making the impedance of the transmitting equipment low and the impedance of the receiving equipment high, the trouble that could arise when making connections between equipment can be avoided. The following table shows the recommended impedances of equipment to be connected to the unit's input and output terminals to provide guidelines on your equipment selection. the input and output levels of the unit and external equipment. Especially note that the unit cannot handle an excessive input because the unit's AUX Input and Effector Input (Channels 7 and 8) are not equipped with a trim control. For external equipment, such as CD players and effectors, select those with an output level control. When the distance between the unit's Microphone Input Terminal (MIC1 6) and connected external equipment exceeds 5 m, select the external equipment with a balanced output terminal whenever possible. If an unbalanced plug is inserted into the unit's Microphone Input Terminal (MIC1 6), the Cold side is shorted with the ground. [Each input/output terminal's level and recommended impedance] Terminal Name Microphone Input Terminal [MIC1-4] Trim Control: Minimum (fully counterclockwise) Maximum (fully clockwise) Microphone Input Terminal [MIC5 and 6] Trim Control: Minimum (fully counterclockwise) Maximum (fully clockwise) AUX Input Terminal [AUX1 and 2] Effector Input Terminal [EFF IN] Recording Output Terminal [REC OUT] Foldback Output Terminal [FB OUT] Effector Output Terminal [EFF OUT] Line Output Terminal [LINE OUT] Level/Recommended Impedance 30 db/600 Ω 66 db/600 Ω 30 db/600 Ω 66 db/600 Ω 10 db/10 kω 10 db/10 kω 20 db/10 kω +4 db/600 Ω +4 db/600 Ω +4 db/600 Ω Equipped Connector Equivalent of XLR3-31 Phone jack (balanced type) Phone jack (balanced type) Pin jack Stereo phone jack Pin jack Unbalanced phone jack Unbalanced phone jack Unbalanced phone jack * 0 db = 1 V 11
8. PROPER SOUND MIXING When connecting the unit to external equipment, check the input and output levels and impedances of both units carefully before connecting. that incorrect connections not only worsen mixing operability, but also adversely affect the sound quality. The unit's microphone input (Channels 1 6) is equipped with a trim control which facilitates mixing operation. Because the input trim control changes a head amplifier gain by varying the head amplifier negative feedback amount, the sufficient dynamic range can be obtained even for a high level signal by setting the appropriate head amplifier gain. Also, by decreasing the head amplifier gain, the S/N ratio can be improved. Input Trim control Head amplifier For example, suppose that a keyboard with output level of 20 db and a 50 db dynamic microphone are connected to the unit. Set the trim controls as shown in the figure on the right. By adjusting each channel's sound volume balance with the trim controls, each channel's level control is set to the same position, facilitating sound mixing. Set each channel's level control to graduations 6 8 when using, and adjust the whole system volume with the master control. Keyboard ( 20 db) MIC1 input Dynamic microphone ( 50 db) MIC2 input 12
9. BLOCK/LEVEL DIAGRAM CH-1 to CH-4 MIC ANT TUNER OPTION MIC CH-7 AUX-1 CH-8 AUX-2 EFF IN +30 +20 +10 0 AUX -10-20 TRIM MINI MIC 1 to 6-30 -40-50 TRIM MAX -60-70 TRIM HA BA CH-5 to CH-6 TRIM HA BA BA BA BA BA BA BA FB-VOL PANPOT CH-VOL EFF-VOL FB-VOL PANPOT CH-VOL EFF-VOL AUX1-VOL BALANCE FB-VOL EFF-VOL AUX2-VOL BALANCE FB-VOL EFF-VOL EQUALIZER MA LA BASS TREBLE EQUALIZER MA LA BASS TREBLE LED METER FB MASTER VOL MA EFF MASTER VOL MA LA LA CH-L MASTER VOL PA CH-R MASTER VOL PA CH-L SPEAKER OUT 4 Ω 60 W CH-R SPEAKER OUT 4 Ω 60 W REC OUT FB OUT EFF OUT SPEAKER OUT 4 Ω 60 W FB/EFF/ LINE REC OUT RF DISTRIBUTER ANT [AS, ER version] AC MAINS [LH version] AC MAINS FOR PREAMP POWER SUPPLY FOR PREAMP POWER SUPPLY FOR POWER AMP FOR POWER AMP CH-L LINE OUT CH-R LINE OUT 13
10. CHARACTERISTIC DIAGRAM Distortion (power amplifier) 5 f=1 khz Power band width (power amplifier) 1% distortion Distortion (%) 10 0 5 10-1 5 Output Power (W) 50 20 10 10-2 0.5 1 5 10 50 100 Output Power (W) 5 10 1 10 2 10 3 10 4 Frequency (Hz) Equalizer characteristics 0 db=1 V 20 BASS MAX TREBLE MAX Output Level (db) 0-20 BASS MIN TREBLE MIN 10 1 10 2 10 3 10 4 10 5 Frequency (Hz) 11. DIMENSIONAL DIAGRAM [Top] [Side] 169 150.5 Unit: mm 418 105 36 450 83 14
12. SPECIFICATIONS Power Source LH Version: 115 V AC or 230 V AC (selectable), 50/60 Hz ER AS Version: 230 V AC, 50/60 Hz Power Consumption 280 W (rated output) Rated Output 60 W x 2, 4 Ω [0.5% THD (1 khz)] Frequency Response 20 Hz 20 khz, +1 to 3 db (AUX input) Noise Measured with TRIM & LEVEL controls for MIC1 and MASTER L&R controls set for maximum. (Speaker Out) Noise level calculated in terms of input: Under 120 db* Output noise level: Under 30 db* (S/N ratio: 54 db) Measured with LEVEL control for AUX1 and MASTER L&R controls set for maximum. Output noise level: Under 66 db* (S/N ratio: 90 db) Maximum Voltage Gain 90 db (MIC1 6 inputs, SPEAKER OUT output) 34 db (AUX1 2 inputs, SPEAKER OUT output) 70 db (MIC1 6 inputs, FB OUT/EFF OUT/ LINE OUT/SPEAKER OUT outputs) 14 db (AUX1 2 inputs, FB OUT/EFF OUT/LINE OUT/SPEAKER OUT outputs) Equalizer Characteristics Treble: 10 khz, ±10 db Bass: 100 Hz, ±10 db Level Meter 7 points ( 20, 10, 6, 3, 0, +3, +6 db) Finish Rolled steel plate, gray, paint Dimensions 450 (w) x 169 (h) x 418 (d) mm Weight 13 kg * 0 db = 1.0 V : The design and specifications are subject to change without notice for improvement. Accessory AC power cord... 1 15