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11 

APPENDIX 2 

 

Specification: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

E45

 

Output power (Watts RMS)  

 

 

 

 

 

   

   

 

 

per channel   

 

 

 

 

           

 

 

 

   

   

 

 

 

      

 

 

8 ohms @ 1kHz 

 

 

 

 

1200 

 

 

 

 

4 ohms @ 1kHz 

 

 

 

 

2250 

 

 

 

 

2 ohms @ 1kHz 

 

 

 

 

3200 

Mono Bridged 
 

 

 

 

8 ohms @ 1kHz 

 

 

 

 

4400 

 

 

 

 

4 ohms @ 1kHz 

 

 

 

 

6400 

THD @ rated power  

 

 

 

 

 

     

4 ohms  1 kHz 

 

 

 

 

<0.009% 

 

 

     

20Hz-20 kHz  

 

 

 

 

<0.03% 

Input CMRR   

 

       

 

 

 

 

 

>90dB 

Hum & Noise  

 

 

 

 

 

 

 

 

-105dB 

Gain  (selectable)  

 

 

 

 

 

 

 

+32Db/+26dB/+35.7dB 

Sensitivity for 

 

 

 

 

 

rated output, 4 ohms  

 

 

 

 

 

 

+9.75dBu/+15.75dBu/+6dBu (1.5V) 

Damping Factor 1 kHz, 8 ohms 

 

 

 

 

>400 

Frequency response   

 

 

 

 

 

 

20Hz-20kHz  -  +0/0.5dB 

Input impedance (actively balanced)   

 

 

 

20k ohms 

Dimensions (mm) - 2U         

 

 

 

 

88x482x428 

Weight 

 

 

 

 

     

 

 

 

 

11kgs 

Power requirement   

 

 

 

 

 

 

230 VAC @ 20 amps max 

 

 

 

 

 

 

 

 

 

 

 

 

 

115 VAC @ 40 amps max 

 

 

Table of PRC settings and resulting Output 
 

 

 

 

 

 

Output Per Channel (Watts)      

Bridged Mode (Watts) 

 
Max Power into 4ohm 

2250 

 

 

 

6400   

 

 

-2dBu PRC Setting 

1400 

 

 

 

4000 

-4dBu PRC Setting 

  900 

 

 

 

2500 

-6dBu PRC Setting 

  560 

 

 

 

1600   

 

 
Max Power into 8ohm 

1200 

 

 

 

4400 

-2dBu PRC Setting 

  800 

 

 

 

2800 

-4dBu PRC Setting 

  525 

 

 

 

1800 

-6dBu PRC Setting 

  350 

 

 

 

1200 

 
Max Power into 2ohm 

3200 

 

 

 

N/A 

-2dBu PRC Setting 

2000 

 

 

 

N/A 

-4dBu PRC Setting 

1250 

 

 

 

N/A 

-6dBu PRC Setting 

  800 

 

 

 

N/A 

 

Summary of Contents for E45

Page 1: ...E45 SERVICE MANUAL MC 2 AUDIO Ltd Units 6 7 Kingsgate Heathpark Industrial Estate HONITON Devon EX14 1YG England Tel 0 1404 44633 Fax 0 1404 44660 www mc2 audio co uk ...

Page 2: ... 3 MAINTENANCE 3 CIRCUIT DESCRIPTION 3 DIS ASSEMBLY 6 RE ASSEMBLY 7 ADJUSTMENTS RE ALIGNMENT 7 APPENDICES 1 EQUIPMENT REQUIRED 9 2 SPECIFICATIONS and PRC 10 CIRCUIT DIAGRAMS PCB710 x 701 x 712 x 703 x LAYOUT DIAGRAM PCB710 701 712 ...

Page 3: ...less it is within a clean room Replacement filter material is available from MC2 Audio No other regular maintenance is required NOTE Any internal cleaning should only be carried out by a competent person CIRCUIT DESCRIPTION 1 GENERAL The E45 amplifier operates in modified class H with mixed bi polar and FET output stages powered from a switchmode power supply This ensures optimum sonic quality and...

Page 4: ...ove ve when PIN3 exceeds the reference set on PIN2 Hence the limiter threshold is set The PRC switches control the gain and therefore the voltage into PIN3 of U102a U202a thus the threshold of limiting can be lowered to reduce the maximum output of the amplifier 4 OUTPUT AMPLIFIER PCB710 The unique MC2 Audio sliding op amp drive circuit combined with multiple bi polar output transistors form the p...

Page 5: ...se conduction of Q114 or Q115 Q214 or Q215 which will pull current through the relevant OPTO coupler LED OPT101 or OPT102 OPTO201 OPTO202 The output transistor of the relevant OPTO coupler will cause comparator U1d to change state and latch due to R12 D9 This will disconnect the speaker output relays RLY4 and RLY5 via D7 and mute the drive signal See Temperature para a d DC SHIFT R24 and R25 detec...

Page 6: ...relays RLY2 and RLY3 which step down the Vcc Vss rails The base of Q4 is driven from PCB700 via CONN1 PIN4 NTC4 senses the IGBT heatsink temperature within the power supply D12 adds a small d c voltage to that on C37 to also control the limiter circuit as above SAFETY COMPONENTS FS1 is a 1AT fuse to protect the low voltage circuits Th Trip1 is the main unit thermal trip fitted to the rear panel 24...

Page 7: ... pillar Disconnect ribbon and audio cables from PCB701 Cut tie wraps as necessary Withdraw display assembly through front panel d PSU PCB712 WARNING ENSURE CAPACITORS ARE DISCHARGED BEFORE PROCEEDING LEAVE UNIT SWITCHED OFF FOR 30 MINUTES Remove spade terminals LIVE NEUTRAL Remove CONNs 2a 2b and CONN1 Remove spade terminals RED BLACK BLUE WHITE YELLOW Remove 5 x M4 retaining nuts and 1 x PZ2 M4 s...

Page 8: ...ct suitable dummy 4 ohm load to relevant speaker output Inject 4dBu 1kHz balanced into relevant input XLR Monitor the output across the 4 ohm load on a suitable audio analyser capable of measuring THD N down to 0 003 If possible monitor the residual signal from the analyser monitor output on an oscilloscope Set VR104 VR204 fully anti clockwise Slowly adjust VR104 VR204 clockwise The THD N should r...

Page 9: ...y Ch A and adjust VR105 on PCB701 to match Ch B in output power NOTE THAT POWER MEASUREMENTS OF BOTH CHANNELS TOGETHER CAN ONLY BE MADE USING A BURST TONE IF A SINE WAVE SOURCE IS USED CONSULT MC2 FOR FURTHER INFORMATION IF REQUIRED There are no further adjustments but a check of power and frequency response should be made with reference to the specification in Appendix 2 ...

Page 10: ... 1 Signal Generator 10Hz to 40 kHz 0 001 THD Burst tone for power measurements 2 Audio analyser capable of measuring dBu Watts 4 ohms THD to 0 003 accuracy Recommend Audio Precision AP1 or similar 3 Oscilloscope 10MHz band width minimum 4 Dummy loudspeaker loads 4 ohm 2000W Qty 2 5 Voltmeter D C volts 1 to 100V 6 Suitable screwdriver trimmer for POTs ...

Page 11: ...ency response 20Hz 20kHz 0 0 5dB Input impedance actively balanced 20k ohms Dimensions mm 2U 88x482x428 Weight 11kgs Power requirement 230 VAC 20 amps max 115 VAC 40 amps max Table of PRC settings and resulting Output Output Per Channel Watts Bridged Mode Watts Max Power into 4ohm 2250 6400 2dBu PRC Setting 1400 4000 4dBu PRC Setting 900 2500 6dBu PRC Setting 560 1600 Max Power into 8ohm 1200 4400...

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