Lowell MA125 Скачать руководство пользователя страница 7

Instruction Sheet

IS-MA60/125/250

Issued: 3-6-18

Lowell Manufacturing Company

100 Integram Drive

Pacific, Missouri 63069 U.S.A.

Call: 800-325-9660

Fax: 636-257-6606

Click: www.lowellmfg.com

7

TELEPHONE CHANNEL INPUT WIRING

GND

_

+

TELEPHONE INPUT

OF AMPLIFIER

From the

Telephone

System

Page-Port

Output

600

W

 Twisted-Pair Wiring

Shielded wiring from the telephone system is typically not required, but if 

shielded wiring is used, drain the shield at the telephone input and butt 

the shield (no connection) at the telephone system page port output.

BUTT

SHIELD

(No connection)

Special Channel 6

Channel-6 (aux  inputs only) are all muted by the Telephone input and by the Channel-1 input if the Channel-1 mute 
switch is in the “ON” position.  Channel-6 has no mic inputs.  The Channel-6 (Aux 6) level control is located to the 
left of the AUX 6 RCA-Phono input jacks.  The Channel-6 aux inputs never mute any other channels.

Muting Priority 3

Channels-3, Channel-4, and Channel-5 (the XLR inputs, screw terminal inputs, and aux inputs) are all muted by the 
telephone  input  and  by  the  Channel-1  input  if  the  Channel-1 

mute  switch  is  in  the  “ON”  position.    Channel-3, 

Channel-4, and Channel-5 never mute any other channels.

Special Channel 2

Channel-2  (XLR  input,  screw  terminal  inputs  and  aux  inputs)  are  all  muted  by  the  telephone  input.    Channel-2, 
however, is  never  muted  by  any  other  channel  including  Channel -1.    The  Channel-2  inputs  never  mute  any  other 
channels, so Channel-2 can be treated as a special input channel that is not affected by any mutes , except the mute 
from the telephone input.

Muting Priority 2

The Channel-1 XLR or screw terminal inputs (not the Channel-1 aux inputs) have the second highest level of muting 
priority.    The  telephone  input  always  mutes  Channel-1.    The  Channel-1  XLR  and  screw  terminal  inputs  mute 
Channels  3-6  as  long  as  the  Channel-1 

mute  switch  is  in  the  “ON”  position.      The  Channel-1  muting  is  active 

whether using the XLR or screw terminal inputs in the microphone mode (

with the aux switch in the “MIC1” position), 

or when  using  the  XLR or  screw  terminal  inputs  in the balanced line level mode (

with the aux switch in the “AUX1” 

position).  Channel-1 never mutes the Channel-2 inputs.

Muting Priority 1

The telephone input Channel-7 has the highest level of muting priority.  The telephone input is never muted by other 
inputs and  the  telephone  input mutes all other  inputs.  The muting caused  by the telephone input  is  not  defeatable 
(in other words, the muting is always on).

AMPLIFIER MUTING-PRIORITY SCHEME

The  amplifier  includes  unique  voice-activated  (VOX)  ducking/muting  circuitry.   When  a  page  is  made, other  inputs 
(such as a music input) that are set up at a lower muting level, softly lower in volume during the page .  If the volume 
of  the  page  is  not  strong,  the  music  will  only  duck  in  volume  (not  be  completely  muted).    If  the  incoming  page  is 
strong in level, the music volume will be completely muted .   When the page has been completed, the volume of the 
music will return to its normal level.  The amplifier has three levels of muting priority as described below:  

TELEPHONE INPUT CHANNEL

The amplifier includes a telephone input Channel-7.  This input accepts a low impedance balanced 600

W

 line level 

input that would typically be available as a page port output from a telephone system.  A Channel-7 level control is 
located on the rear panel directly to the right of the telephone input terminals.

DRAIN

SHIELD

Содержание MA125

Страница 1: ... the POWER AMP IN jack A chassis ground termination screw is available on the rear panel The front panel includes channel 1 5 volume controls treble and bass controls a master volume control a main power switch and an output level LED display Rack mounting brackets are included with each model Optional Accessories sold separately Lowell Manufacturing offers a full line of 19 equipment cabinets wal...

Страница 2: ...To completely disconnect this apparatus from the AC mains disconnect the power supply cord plug from the AC receptacle This apparatus shall be connected to a mains socket outlet with a protective earthing connection When permanently connected an all pole mains switch with a contact separation of at least 3 mm in each pole shall be incorporated in the electrical installation of the building If rack...

Страница 3: ...BS MA250 29LBS Color Black Note Black rack mounting brackets are included Speaker Level Outputs Screw terminal strip 4W 8W 25V 70V MA60 60W RMS MA125 125W RMS MA250 250W RMS Tape Outputs Dual parallel RCA phono jacks 1V 4 7kW output Preamp Pre Outputs Dual parallel RCA phono jacks 1V 600W output Convenience AC Outlet 500W maximum unswitched outlet Mic Inputs 1 5 XLR receptacle or screw terminals 1...

Страница 4: ...jack or screw terminals Circuit Breaker for Convenience Outlet 1 2 3 4 5 6 7 8 9 10 11 12 Circuit Breaker for Amplifier Earth Ground Connection Screw Power Amp Input RCA Jack Preamp Output RCA Jacks Tape Output RCA Jacks Aux 6 Level Control Aux 6 Input RCA Jacks Aux 5 Input RCA Jacks Mic 5 Aux 5 Selector Switch Mic 5 Input XLR Jack Mic 4 Input XLR Jack 4 2 13 14 15 16 17 18 19 20 21 22 23 Convenie...

Страница 5: ...amplifier operating temperature of no higher than 92o F To mount the amplifier in a Lowell equipment cabinet use standard 10 32 Phillips head machine screws like the Lowell model RS or RSP rack screws with integral plastic washers to protect the finish of the front panel of the amplifier Rack mounting brackets for the amplifier are included The AC power cord provided with this amplifier is equippe...

Страница 6: ...telephone cables or other low voltage wiring that could pick up the signal from the higher level speaker cables DO NOT run high impedance unbalanced wiring more than 20 to avoid picking up noise and affecting the frequency response of the sound system DO use shielded cable for all microphone and line level cables except the balanced 600 ohm input line from a telephone system may be twisted pair ca...

Страница 7: ... or screw terminal inputs not the Channel 1 aux inputs have the second highest level of muting priority The telephone input always mutes Channel 1 The Channel 1 XLR and screw terminal inputs mute Channels 3 6 as long as the Channel 1 mute switch is in the ON position The Channel 1 muting is active whether using the XLR or screw terminal inputs in the microphone mode with the aux switch in the MIC1...

Страница 8: ...mono outputs to two different devices such as a booster amplifier or equalizer As shown in the AMPLIFIER BLOCK DIAGRAM on page 3 the PREAMP OUT jacks are fed from the output of the master volume control In other words if you wish the levels to be adjusted as a result of changes in the setting of the MASTER volume control that may need to be adjusted due to crowd noise in a live performance the PRE...

Страница 9: ...per Between Pre Out And Power Amp In OPTIONAL 1 3 OCTAVE EQUALIZER BY OTHERS High Z Input High Z Output Type 1 Type 1 Connection to two 2 1 3 octave equalizers using Lowell PA250A booster amplifiers with similar and different types of loudspeakers Note Similar speakers are fed by the same equalizer LOWELL PA250A BOOSTER AMPLIFIER Aux In Jack To Speakers Note Jumper cords shown are not included Ins...

Страница 10: ...amage the amplifier and void the manufacturer s warranty It is also important to pay attention to the power rating of the speakers used If an 8W speaker is fed from the 8W output of an amplifier and the amplifier is turned all the way up the speaker will receive the maximum power output of the amplifier A speaker must be chosen with sufficient power handling capacity for the amplifier used For exa...

Страница 11: ...M 572 5 watt 70V 25V dual voltage transformer That means that this speaker can be used on both 70V systems and 25V systems The 8W secondary of the transformer is connected directly to the 8W input terminals on the 810 speaker The primary has transformer taps for either 70V or 25V at 0 25W 0 5W 1W 2W and 5W When a designer is mapping out the coverage of these ceiling speakers he she will determined...

Страница 12: ...ker load to no more than 106 25W Since we know from our example that 100 speakers would be required it is obvious that tapping the speakers at 1W is the best choice Some system designers feel it is best to tap the speaker transformers as high as possible Consider an example where a sound system that has a 125W 70V amplifier only has 10 speakers If the transformers are tapped at 0 25W each the tota...

Отзывы: