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5

INTRODUCTION 

 
Your  MC750  digitally  controlled  power  amplifier  represents  the  latest  technology  in  control  circuitry 
coupled to a no compromise high quality class AB power amplifier. There is no dynamic switching of the 
audio or power rails (a very common  method of achieving extra power at the expense of audio quality) 
thus ensuring optimum sonic performance.  
 
The digital control monitors the operating parameters and adjusts the amplifier to suit the conditions. Fan 
speed and supply rails are varied as required to keep the amplifier within its temperature limits. The levels 
are adjusted  by  specially  selected,  high  performance,  digitally  controlled  attenuators.  Signal limiters  are 
included,  the  attack  and  release  times  of  which  can  be  adjusted  internally  by  the  bit  switches  on  the 
control PCB (printed circuit board). 
 
The amplifiers include full DC and short circuit protection which automatically re-connects when the fault 
is cleared. 

 

INSTALLATION

ELECTRICAL 

 
The amplifier  has  been  manufactured  to  comply  with  your  local  power  supply  requirements,  but  before 
connecting the unit to the supply, ensure that the voltage (printed on the rear panel) is correct and that a 
mains fuse of the correct type and rating has been fitted. 
 

Make sure power outlets conform to the power requirements listed on the back of the unit. Damage 
caused by connecting to improper AC voltage is not covered by the warranty.

 

 

SAFETY WARNING 

 
This unit is fitted with a 3 wire power cord. For safety reasons, THE EARTH LEAD SHOULD NOT BE 
DISCONNECTED IN ANY CIRCUMSTANCE. If ground loops are encountered consult the section on 
input connections later in this manual. 
 
WHERE A FIXED MAINS LEAD IS FITTED, THE WIRING COLOURS ARE: 
 
 

 

 

 

 

 

 

 

230V AREAS: 

EARTH = GREEN AND YELLOW 

 

 

 

 

 

 

 

 

 

 

 

NEUTRAL = BLUE 

 

 

 

 

 

 

 

 

 

 

 

LIVE = BROWN 

 
 

 

 

 

 

 

 

 

120V AREAS: 

EARTH = GREEN 

 

 

 

 

 

 

 

 

 

 

 

NEUTRAL = WHITE 

 

 

 

 

 

 

 

 

 

 

 

LIVE = BLACK 

 
TO  PREVENT THE  LIKELIHOOD  OF  SHOCK  OR  FIRE  HAZARD,  DO  NOT  EXPOSE THE  UNIT 
TO RAIN OR MOISTURE. 
 
TO  AVOID  ELECTRICAL  SHOCK  DO  NOT  REMOVE  COVERS.  REFER  ALL  SERVICING  TO 
QUALIFIED PERSONNEL. 
 
DO  NOT  USE  THE  UNIT  IF  THE  ELECTRICAL  POWER  CORD  IS  FRAYED  OR  BROKEN.  The 
power  supply  cords  should  be  routed  so  that  they  are  not  likely  to  be  walked  on  or  pinched  by  items 
placed upon or against them, paying particular attention to cords and plugs and the point where they exit 
from the appliance. 
 
ALWAYS  OPERATE  THE  UNIT  WITH  THE  AC  GROUND  WIRE  CONNECTED  TO  THE 
ELECTRICAL  SYSTEM  GROUND.  Precautions  should  be  taken  so  that  the  means  of  grounding  of  a 
piece of equipment is not defeated. 
 
DO  NOT  REMOVE  THE  LID.  Removing  the  lid  will  expose  you  to  potentially  dangerous  voltages. 
There are no user serviceable parts inside. 

Summary of Contents for MC1250

Page 1: ...MC750 OPERATING INSTRUCTIONS MC 2 AUDIO Ltd Units 6 8 Kingsgate Heathpark Industrial Estate HONITON Devon EX14 1YG England Tel 0 1404 44633 Fax 0 1404 44660 www mc2 audio co uk ...

Page 2: ...S Inputs 8 Outputs 9 Rear panel switches 9 OPERATION Switching on 10 Level controls 10 Mute switches 10 Link switch 10 Level indicator 10 Limiters 10 Temperature control 11 Fault indicators 11 2 ohm LED 11 INTERNAL CONFIGURATION SWITCHES 12 REMOTE CONTROL OPTION 13 REMOTE CONTROL SET UP INSTRUCTIONS 14 ...

Page 3: ...tional Specifications Input Impedance Active balanced k ohms 20 20 Input CMRR dB 60 60 Hum Noise dB below max output 106 106 Damping Factor 1kHz into 8 ohms 400 400 Signal Limiters set to prevent excessive clipping Yes Yes Protection Short circuit DC output Temperature Yes Yes Mains in rush control Yes Yes Output Power watts into 8 ohms Sine wave 1kHz 575 375 Continuous music with Crest Factor of ...

Page 4: ...both on the apparatus and the packaging A product Declaration of Conformity statement and information regarding auxiliary apparatus and specifications required to meet conformity is available on request from our Customer Service Department on 44 0 1404 44633 This amplifier will only operate to its very high specification if it is installed and operated as described in this manual ...

Page 5: ...d rating has been fitted Make sure power outlets conform to the power requirements listed on the back of the unit Damage caused by connecting to improper AC voltage is not covered by the warranty SAFETY WARNING This unit is fitted with a 3 wire power cord For safety reasons THE EARTH LEAD SHOULD NOT BE DISCONNECTED IN ANY CIRCUMSTANCE If ground loops are encountered consult the section on input co...

Page 6: ...ave fallen into the apparatus the apparatus has been exposed to rain or moisture does not operate normally or has been dropped 15 Do not expose this equipment to dripping or splashing and ensure that no objects filled with liquids such as vases are placed on the equipment 16 To completely disconnect this equipment from the AC mains disconnect the power cord from the mains circuit breaker 17 Where ...

Page 7: ...l appareil l appareil a été exposé pour pleuvoir ou l humidité n opère pas normalement ou a été baissé 15 N exposez pas cet équipement au fait de tomber goutte à goutte ou au fait d éclabousser et garantissez qu aucun objet rempli des liquides comme les vases n est placé sur l équipement 16 Pour complètement débrancher cet équipement de la conduite principale de courant alternatif débranchez la co...

Page 8: ...ONS INPUTS The inputs are made via 2 separate 3 pin XLR connectors wired in parallel Either socket can be used as the input the other one can be used to link to other amplifiers daisy chain or to the other input for mono signals They are electronically balanced and should be connected via a high grade twin core screened cable as follows PIN1 Screen see note PIN2 Hot signal PIN3 Cold signal The amp...

Page 9: ...ly joined NOTE The load impedances change when operating in the bridged mode See Load Power section below LOAD POWER SWITCH 2 ohm 4 ohm In the 4 ohm position the amplifier supply voltages are set up for loads of 4 ohms and above Lower impedance loads can be connected but the internal current limit circuit could cause clipping and unless the signal is very dynamic the internal temperature rise will...

Page 10: ...ich show the signal headroom before clipping The 0dB LED is set at approximately 1 2dB below clipping They are referenced to the supply voltages and automatically adjust when the supply changes When the level controls are adjusted the level indicators change function and show the level control position They return to their normal function after the level has been set Limiters The MC750 incorporate...

Page 11: ...er to know this All other functions remain the same Normal dynamic signals will not cause the amplifier to overheat unless the air filter is clogged or the ventilation is inadequate See installation section Fault Indicators If the outputs are shorted or if DC is present the control circuit will disengage the outputs and the fault LED will illuminate The controller will keep monitoring the amplifie...

Page 12: ...ttack time of the limiter ON Fast OFF Slow MAINTENANCE ENSURE THAT ELECTRICAL POWER TO THE UNIT IS DISCONNECTED BEFORE CARRYING OUT ANY MAINTENANCE The filter behind the air intake apertures on the front of the MC range amplifiers should be cleaned or replaced periodically e g 12 24 months Filters in amplifiers located in more dirty atmospheres may require more frequent maintenance The filter shou...

Page 13: ...om the computer This allows the system to be set up to the client s requirements and then made secure against manual interference Two levels of security are available on the management control system through the use of passwords which permit a higher level access for the senior manager through one password and more limited access at a lower level to a number of other users Full Windows software is...

Page 14: ...either end of the cable and connected as follows PIN 2 hot positive PIN 3 cold PIN 5 screen Configuring the PC 1 Launch Amplifier Explorer program can be downloaded from www mc2 mc2 audio co uk 2 Click on the Tools menu and select Serial link setup Then SET OPERATING SYSTEM e g WIN98 SET COM PORT NUMBER SET PORT ADDRESS This happens automatically Set up is now complete Each amplifier has its own i...

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