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Mode 2…Priority Pre-select switches (1-4) Down

In this mode, only one mic at a time can be “on.”  The lockout bus shuts down all other mics

until the first speaker pauses. As soon as the controlling microphone goes silent, the lockout

bus goes inactive and any other mic can come on. This switching takes place without any 

syllable-grabbing delay, or pops or clicks. (This mode is known as “First-come-first-served” 

or “Filibuster.”)

This mode is very useful when the gain setting of the overall sound system must be close to

the threshold of feedback, and additional microphones coming on could throw the system into

feedback. The SmartMixer will not allow multiple microphones to be on at the same time in this

mode. The switching is so fast and silent that the meeting can still be completely interactive.

Mode 3…One Priority Pre-select switch Up

The selected priority microphone can come on at any time and can mute any other mic that is

on (popularly called “The Chairperson” mode).

(Note that there may be special circumstances where two or three mics could be set to priority,

so those speakers could talk whenever desired, but still mute one or two non-priority mics.)

If multiple SmartMixers are used with AT8325/1.0 Link Cables, Priority Pre-select switches

on all channels in use will have the control effects described above.

The selected priority microphone(s) will mute only those non-priority microphones within the

same unit.

NOMA

The NOMA is factory set in the “off ” position. To turn on the NOMA function, unplug the unit,

remove the top cover and change the setting of the switch designated on the circuit board by

“SW25” (Figs. 4 and 5, page 11).

NOMA serves to maintain overall system gain by proportionately reducing amplifier gain as

the number of open microphones increases. In a sound reinforcement system, this can tend to

preserve the feedback margin and system stability. However, this action necessarily reduces

the sound level of each individual person speaking, which may not be desired. In the end, use
of NOMA often comes down to the preferences of the system’s designer and/or operator.

Generally speaking, use of NOMA is not desirable in applications such as teleconferencing,
recording or broadcasting.

Auxiliary Input

The Aux input is an RCA jack accepting auxiliary-level (–10 dBV) input from sources such as

tape decks and VCRs. There is no signal processing of the Aux input.

Preamplifier Gain

The SmartMixer has a substantial gain range, allowing it to accept a wide variety of micro-

phones. However, if in some instances higher-output microphones are used for close talking, 

it may be necessary to reduce the preamplifier gain.  This can be done by changing switch 

settings inside the unit. With the unit unplugged from its AC source, remove the two screws

on each side of the unit and carefully lift off the top cover. Locate the internal switches 

designated on the circuit board by “SW2,” “SW8,” “SW14” and “SW20” (Figs. 4 and 5, page 11).

A “control map” drawing will be found on the inside of the top cover. Changing the settings 

of these internal switches will cause a gain reduction of 10 dB for channels 1, 2, 3 and 4

respectively. 

9

Содержание SmartMixer AT-MX351

Страница 1: ...AT MX351 SmartMixer Automatic Mixer Installation and Operation ...

Страница 2: ......

Страница 3: ...r FCC You are cautioned that any changes or modifications not expressly approved in this manual could void your authority to operate this equipment Note This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is oper...

Страница 4: ...e to rain or moisture Pour prévenir feu ou choc électrique ne pas exposé l appareil à la pluie ou à l humidité Caution Avis For continued protection against fire hazard replace only with same type rating of fuse Pour poursuivre la protection contre le feu replacez la fusible de même type cote Warning Attention There are some sharp edges inside To reduce the risk of injury do not remove cover Bord ...

Страница 5: ...s ensures proper gating levels for existing ambient sound conditions Priority Pre select To custom tailor conferencing needs the mode of each microphone channel can be indepen dently switched via the front panel Priority Pre select DIP switches The combination of switch settings results in three different modes of priority selection operation In any of the three modes of operation when everyone st...

Страница 6: ... 1 4 A switch in the up position assigns the respective channel priority over the other channels A priority channel can not be locked out by other channels Any combination of priority non priority selections is allowed 8 Manual mode switch Setting this switch in the up position bypasses all of the SmartMixer s automatic functions except limiting and NOMA if selected 9 Lockout LED indicator Shows w...

Страница 7: ...evel 10 dBV auxiliary input 6 Preamp Outputs Independent unbalanced 10 dBV switchable pre post controller outputs from mic channels 7 Inputs Balanced microphone inputs for low impedance dynamic or condenser mics Can be changed to line level inputs via internal switches see page 10 XLRF type connectors Can supply 48V phantom power via internal switches 8 Power input 120V 230V AC 50 60 Hz Select inp...

Страница 8: ...e the unit will behave like a conventional mixer all automatic functions are bypassed except for limiting and NOMA if selected 11 Adjust the Master level control for desired output level This control is at the last stage in the mixer and does not affect microphone gain threshold setting meter indication monitor or preamp outputs Priority Microphones and the Lockout Bus Channels 1 4 Once the Gain c...

Страница 9: ...f position To turn on the NOMA function unplug the unit remove the top cover and change the setting of the switch designated on the circuit board by SW25 Figs 4 and 5 page 11 NOMA serves to maintain overall system gain by proportionately reducing amplifier gain as the number of open microphones increases In a sound reinforcement system this can tend to preserve the feedback margin and system stabi...

Страница 10: ...the circuit board by SW1 SW7 SW13 and SW19 Figs 4 and 5 page 11 Changing the settings of these switches will disable phantom power on channels 1 2 3 and 4 respectively Note that although they do not require phantom power for operation most balanced output dynamic microphones can be used without disabling the SmartMixer s phantom power Output Level LED Meter The Output Level LED meter is factory se...

Страница 11: ...1 0 dB 10 dB VR2 1 0 dB 10 dB VR2 1 0 dB 10 dB VR5 1 0dB 10dB VR8 1 0dB 10dB VR1 1 Phantom Of f SW1 30 dB SW2 40 dB Phantom Of f SW7 30 dB SW8 40 dB Phantom Of f SW13 30 dB SW14 40 dB Phantom Of f SW19 30 dB SW20 40 dB SW22 Of f O n SW4 Of f O n SW10 Of f O n SW16 Of f O n SW27 Pe ak RMS Meter Of f On SW25 NOMA Line Mic Outpu t SW26 Mic Line SW9 Mic Line SW1 5 Mic Line SW21 SW6 SW12 SW18 SW2 4 Gat...

Страница 12: ...To gate these outputs unplug the unit remove the top cover and locate the switches designated on the circuit board by SW6 SW12 SW18 and SW24 Figs 4 and 5 page 11 Change the switch position s to Gating for channels 1 2 3 and or 4 respectively as desired Input Limiters Independent adjustable limiters are available on all mic channels To adjust the limiter threshold of channel 1 unplug the unit remov...

Страница 13: ...l LED on the front panel the channel s associated Control Voltage Out goes high 4 VDC See chart on page 12 for pin connection This signal can be used to light indicator lamps switch speaker zones on and off select video cameras etc The control voltage should not be connected directly to an inductive load such as a relay coil as damage to the mixer may result Several interface circuit possibilities...

Страница 14: ... linked with AT MX341 and or AT MX341a mixers the NOMA function will pass through the AT MX341 a models but their mics will not be included in the NOMA calculation Rack Mounting Provided with each mixer are two rack ears and six self tapping screws to attach the ears to the unit which allow the unit to be mounted in a 1U rack space Security Caps For permanent installations where microphone selecti...

Страница 15: ...put Noise1 128 dBV 150 ohms at maximum gain Input Attenuation 10 dB Mic Line Input Pads 50 dB Maximum NOMA Attenuation 20 dB up to 100 mics on simultaneously Microphone Phantom Power 48V DC Control Voltage Out 4V DC Power Supply 120V 230V AC switchable 50 60 Hz 10W Operating Temperature 32 to 104 F 0 to 40 C Dimensions 16 93 430 mm W x 9 38 327 mm D x 1 75 44 mm H including feet knobs and connecto...

Страница 16: ...or failure to use product in accordance with instructions This warranty is void in the event of unauthorized repair or modification For return approval and shipping information contact the Service Department Audio Technica U S Inc 1221 Commerce Drive Stow Ohio 44224 Except to the extent precluded by applicable state law A T U S will have no liability for any consequential incidental or special dam...

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