Powered Mixer
Total Page:16
File Type:pdf, Size:1020Kb
Operating Instruction Manual POWERED MIXER Model MX-401 Toa Electric Co., Ltd. KOBE, JAPAN Contents General Description 2 Features 2 Front Panel [Names of components & their usage] 3 Rear Panel [Names of components & their usage] 4 Connection Examples 5 Input Connections 6 Block and Level Diagrams 7 Specifications 8 Characteristics Diagrams 9 Appearance 9 Precautions 1. XLR Type Audio Connector The connectors are wired as follows. The pin 1 is ground (shield), the pin 2 cold (low, minus), the pin 3 hot (high, plus). 2. Description of components and functions on the MX-401. Various descriptions are applied, depending on each manufacturer. In our Operating and Instruction Manual explanation of components and functions is made according to our usage for them. General Description The TOA MX-401 is a very compact, four channel self-powered mixer. It was designed to deliver maximum features and performance in a cost-effective portable PA package. The MX-401 features four input channels, one program output, and one Foldback output. The internal amplifier is rated at 100 watts into an 8 ohm load, and 150 watts into 4 ohms. Each input channel has an electronically balanced XLR connector, and a high- impedance unbalanced 1/4" phone jack. In addition, each channel features two-band EQ, a pre-EQ Foldback send, and post-EQ reverb send. The master control section features a patchable 5-band graphic equalizer, a quality 3- spring reverb, a full patch bay with 1/4" phone auxiliary and RCA tape inputs, and master volume controls for Program, Foldback, and Reverb return to both. The power amp protection circuitry and autocomp compressor, both with LED's, are also located in this section. Features 1. Four input channels 2. 100 watts into 8 ohms, 150 watts into 4 ohms 3. Patchable 5-band graphic EQ 4. Auto Comp compression unit w/LED 5. Built-in spring reverb 6. Power amp protection circuitry w/LED 7. Full patch bay 8. Aux input w/level control, RCA jacks and parallel phone 1/4" jacks. 9. Reverb level to PGM and FB 10. Independent Foldback mix. Each Channel 1. Input level control 2. Two band EQ 3. Pre-EQ Foldback send 5. Low-Z electronically balanced XLR input 6. Hi-Z unbalanced 1/4" input — 2— Front Panel Reverb to Foldback Graphic Equalizer Power Amp Compression Control (REV TO FB) (EQUALIZATION) Indicator High Equalizer Control This control adjusts the amount The graphic equalizer is 5 inde- (COMP) (HIGH) of reverb signal that is returned pendent active bands (filters), The Comp LED lights when the The high EQ control alters the to the foldback buss and thus the providing 12dB of boost or cut at internal compressor is activated. high frequency response of the level of reverb contained in the each center frequency. The "0" The compressor is provided to input channel, providing ±13dB on-stage monitor mix. detented position provides flat protect speaker systems by com- at 10kHz, and ±15dB at 20kHz of audio response. pressing the input signal level of continuously variable active Reverb/Control the power amplifier when clip- shelving equalization. The "0" ping occurs in the output stage. detented position provides flat (REV) Foldback Master Control (FB) This control determines the Frequent flashing of the LED is audio response. The FB master control adjusts not reason for alarm. However, a level of signal assigned to the re- the overall combined signal level verb mixing buss. Rotating the constant or steady light indicates of the four independent channel that the MX-401 is being over- control clockwise increases the foldback sends, and thus the Low Equalizer Control amount of reverb in that channel. driven and that the internal level of the entire on-stage moni- power amplifier is possibly (LOW) tor mix. The low EQ control provides Foldback Control (FB) "under powered" for that applica- ±13dB at 100Hz and ±15dB at tion. The output level of the MX- The Foldback control deter- Aux Level Control (AUX) 50Hz of continuously variable mines the level of signal assign- 401 should be decreased until the This control sets the overall level LED only flashes intermittently. active shelving equalization. ed to the foldback mixing buss, of the Aux input signal. The "0" detented position pro- thus setting the level of that vides flat audio response. channel in the on-stage monitor Power Indicator LED mix. (POWER) The indicator LED lights when the power switch is "on". Power Amp Protection Indicator (PROTECT) The indicator LED lights if the Input Level Control Reverb to Program Control power amplifier output is short- (LEVEL) (REV TO PGM) Program Output Jack ed, if the temperature of the unit The level control provides con- This control adjusts the amount (PGM OUT) rises above acceptable levels, or tinuously variable adjustment of reverb signal that is returned The PGM Out jack is provided if DC is drifted to the speaker of the channel output to the to the program buss and thus the for connection to external equal- outputs. If the LED should light, program mixing buss, thus level of reverb contained in the izers and/or power amps, deriv- speaker wiring and ambient determining the level of that main sound system. ing its signal prior to the internal temperature of the MX-401 channel in the main sound GEQ and power amp. Nominal should be checked. If the LED system mix. Since the reverb Program Master Control output level is +4dB with an remains lighted, the unit should signal is "post" this control, an (PGM) impedance of 600 ohms. be referred to qualified service increase in the level of the The PGM control adjusts the personnel for repair. channel's output will also result overall combined signal level of Graphic Equalizer Input Jack Note: in a corresponding increase in the four independent channel (GEQ IN) The MX-401 protection circuitry the reverb effect of that channel. level controls, and thus the level The GEQ input jack allows the will (1) detect 'faulty conditions' The nominal level of the input of the main sound system. graphic equalizer to be used in- within the power amplifier, (2) level control is at the "10" posi- dependently of the MX-401 with give a visual indication, and (3) tion. Aux Input Jacks other external equipment, or the automatically shut down until (AUX IN) internal power amplifier and the the fault condition is alleviated. High Impedance Connectors The phone jack and RCA pin graphic equalizer with external This special circuitry ensures (HIGH Z) jacks are wired in parallel, with equipment. When a plug is maximum reliability and vir- These connectors are unbal- an input level of —20dB. When a inserted, the main mix from tually eliminates equipment anced, standard 1/4" phone jacks plug is inserted into the phone the program buss is disconnected damage due to unsafe or fault with an input impedance of 27k jack, the RCA pin jacks are from the graphic equalizer and conditions. Please refer to fault ohms, and an input level of automatically switched out of the power amplifier. The nomi- protection table on page 4 for —35dB. When a plug is inserted the AUX circuitry. nal input level is +4dB with an full explanation of this im- into the high -Z input, the cor- input impedance of 50k ohms. portant feature. responding XLR connector is Foldback Output Jack automatically switched out of the (FB OUT) input circuitry. This jack is for connection to Graphic Equalizer Output Jack Power Amplifier Input Jack external power amplifiers and/ (GEQ OUT) (PWR IN) Low Impedance Connectors or equalizers for the on-stage This jack allows the MX-401 The PWR Amp input jack allows (LOW Z) monitoring system. Nominal and the internal graphic equal- the internal power amplifier to The XLR connectors are low im- output level is +4dB with an izer to be used with an external be used with external equip- pedance, electronically balanced impedance of 600 ohms. If the power amplifier, or in conjunc- ment. When a plug is inserted, inputs with an input impedance internal power amp and equal- tion with the GEQ in jack, to be the power amp is automatically of 1k ohms. izer are to be used for the on- used independently of all other disconnected from the MX-401 stage monitor system, the FB MX-401 circuitry. Nominal mixer section. The nominal in- output should be connected to output level is +4dB with an put level is +4dB with an input the GEQ input jack. impedance of 600 ohms. impedance of 10k ohms. — 3— Rear Panel Power Switch (POWER) Cord Wrap The power switch is a three- The cord wrap is provided for position type with the middle convenient storage of the power position being the "off position. cord when t h e MX-401 is not in The MX-401 should be operated use. in the switch position which Caution - The power cord should produces the lowest amount of always be completely removed system hum. from the cord wrap prior to operation of the unit. This will Speaker Jacks (SPEAKERS) insure maximum cooling of the The speaker outputs are stand- MX-401 For the same reason, ard 1/4" phone jacks wired in adequate clearance should be parallel. Speaker cables (recom- maintained between the rear mend at least #18 gauge wire) panel and any other surface (4-6 should be connected between inches should do). The vents on the MX-401 and the speaker the bottom and top of the MX- systems prior to applying power 401 are also provided for convec- to the unit. tion cooling. These vents should be kept clear and open.