SERVICE INFORMATION AMC+120P POWER AMPLIFIER CONTENTS: OPERATION MANUAL SCHEMATIC DIAGRAM COMPONENT OVERLAY TEST PROCEDURE REPLACEMENT PARTS LIST SERVICE BULLETIN Australian Monitor 1 Clyde Street, Silverwater NSW 2128 Australia +61 2 9647 1411 www.australianmonitor.com.
+ AMC SERIES 120W / 250W POWER AMPLIFIERS INSTALLATION AND OPERATION MANUAL
IMPORTANT SAFETY INFORMATION 1. Save the carton and packing material even if the equipment has arrived in good condition. Should you ever need to ship the unit, use only the original factory packing. 2. Read all documentation before operating your equipment. Retain all documentation for future reference. 3. Follow all instructions printed on unit chassis for proper operation. 4. Do not spill water or other liquids into or on the unit, or operate the unit while standing in liquid. 5.
INTRODUCTION AND CONTENTS The Australian Monitor Installation Series AMC+ range of booster amplifiers take the rugged reliability of the famous AMIS range and deliver the same high quality audio reinforcement, in a low cost, 2 rack unit package. The AMC+ booster amplifiers are available in 120 & 250 watts & offer 100 volt or 4 ohm outputs.
FRONT PANEL 3 3 2 1 2 1 1 On This LED indicates the unit is powered “on”. 2 Power This switch switches power on or off the mains. The up position is on. 3 Vents Air intake for fan cooling on AMC+250P only.
REAR PANEL 4 3 1 Input These 3 pin XLR sockets accept the source input for each channel. One input is a male XLR, the other is a female XLR. The male XLR is normally used as a thru output. When wiring from unbalanced sources, pins 1 and 3 should be shorted together (see Installation section). The input sensitivity (voltage required to drive amplifier to maximum power) of the amplifier is 150mV (-14dBu) with the Input Level Control set at maximum.
INSTALLATION Mounting When rack mounting, it is advisable to allow 1 rack space above and below the amplifier. When multiple amplifiers are mounted in a rack, exhaust fans should be used on the rack. Airflow for cooling the AMC+120P is by convection from bottom to top. Airflow for cooling the AMC+250P is by fan from front to side. Output 100V 70V 4 ohm Distance Direct Output The output terminal strip accepts wire sizes from 16-22AWG (1.5mm2 – 0.35mm2) or spade lugs.
TROUBLESHOOTING AND BLOCK DIAGRAM Troubleshooting Guide Trouble Likely Cause Remedy Power LED not on Power not reaching amplifier Check power switch is on Check mains connection Check mains fuse Distorted sound No sound but amp is on Output is short circuited Check speaker loads for shorts Input is overloaded Reduce input level at source Output is being over driven Reduce volume levels Volume controls down Check volume controls Amplifier has overheated Check for obstructions above and belo
DIMENSIONS Dimensions the same for both the AMC+120P and the AMC+250P PAGE 8 AMC+ SERIES INSTALLATION AND OPERATION MANUAL
SPECIFICATIONS AMC+ 120P AMC+ 250P POWER OUTPUT (0.5%THD, 1KHZ) 120W 250W S/N RATIO >88dB >88dB 50Hz-20kHz 40Hz-20kHz Better than 0.5% Better than 0.5% 150mV 20k 10dB 150mV 20k 10dB 4A 2A 8A 6.3A 3.15A 10A (x2) SIZE (WXHXD) 482 x 88 x 281mm 19” x 3.5” x 11.1” 482 x 88 x 384mm 19” x 3.5” 15.1” NET WEIGHT 10.5kg 23.1lb 11.5kg 25.3lb SHIPPING WEIGHT 12.5kg 27.6lb 14kg 30.8lb 525 x 175 x 385mm 20.7” x 6.9” x 15.2” 525 x 185 x 470mm 20.7” x 7.3” x 18.
AUSTRALIA AND NEW ZEALAND www.australianmonitor.com.au SYDNEY MELBOURNE ADELAIDE AUCKLAND (NSW SALES) (VIC & TAS SALES) (SA & NT SALES) (NZ SALES) 1 Clyde Street Silverwater NSW 2128 Private Bag 149 Silverwater NSW 1811 Phone: (02) 9647 1411 Fax: (02) 9648 3698 Email: nsw@audiotelex.com.au 22/277 Middleborough Road Box Hill VIC 3128 PO Box 151 Blackburn South VIC 3130 Phone: (03) 9890 7477 Fax: (03) 9890 7977 Email: vic@audiotelex.com.
1 2 3 4 5 6 7 8 R44 10k A A C9 N/C R3 22k Driven by balanced signal R13 10k R17 100R R4 330k R21 R23 1k C3 4.7u/25 T3 BD139 R11 1k C16 1n CN1 VCC C17 1n C2 220n R2 1k5 R9 2k2 R12 1k C4 4.7u/25 R10 100R R32 470R BIAS O/P TXFR1 R42 10k R33 0.39R/5W R35 0.39R/5W PR1 1k R37 *** T15 BC546B T8 TIP41C C8 N/C D2 1N4007 BIAS R34 0.39R/5W R36 0.
1 2 3 4 5 6 R44 10k C9 N/C R3 22k A R17 100R BIAS CN1 R4 330k VCC R21 1k C3 4.7u/25 T3 BD139 R11 1k C16 1n TH1 24V R8 2k2 BC639 C17 1n B C2 220n R9 2k2 R12 1k C4 4.7u/25 R10 100R R16 10k R20 100R BIAS O/P TXFR1 R42 10k R33 0.39R/5W R35 0.39R/5W R37 0.39R/5W 70V R26 56R 0R C8 BIAS R34 0.39R/5W R32 470R R36 0.39R/5W PR1 1k T15 BC546B Com T8 TIP41C N/C D2 1N4007 R43 1k R38 0.
T12 R36 R20 T10 R34 R8 R30 J9 R2 GND J4 T5 T11 T16 R40 J18 R39 CN2 F1 C6 R35 CN3 T9 R33 C5 J6 T15 J10 TH1 J11 D7 +24V T14 R38 R43 C7 J7 J5 J17 TH+ R29 R3 T6 J13 R42 R41 R1 J12 R6 J2 R4 R10 J1 R31 R21 R24 C3 R9 R7 J8 PR1 C1 C13 C14 CN1 GND C16 R44 J3 R11 R12 T7 D1 R23 R14 D2 R15 R13 T8 R22 R26 R32 T1 T2 C2 IN- C4 C17 C9 IN+ R5 R45 C10 T3 T4 R16 C8 R25 T1 R R19 C15 R17 R18 R28 R27 T13 D3 R37 D4 D5 D6 AMC+120 AMP CN5 CN4
TEST PROCEDURE XXXX-1 MODEL: AMC+120P Rev A 22/09/08 Original Outline 1. Physical checks 2. Set up amplifier for test 2.1. Fuse check 2.2. Connections 2.3. Reset controls 3. Power up 3.1. Voltages 3.2. Bias setup 4. Initial AC Checks 4.1. Signal check and gain of amp 4.2. Emitter current check 4.4. Outputs 4.5. Phantom power 5. THD 6. Sensitivity 6.1. Input 7. Bandwidth 8. Phase 9. Current Limit 10. Noise floor / SNR 11. Fan/Thermal check 12. Final check for damage 13. Factory setting 14. Listening Test 14.
Test Procedure VISUAL INSPECTION STAGE 1. Physical checks • All screws for tightness (esp.
(P/F) Slowly adjust the preset PR1 so that you get 4.5mVDC (+/-0.5mVDC) reading. Check Quiescent Voltage across all Emitter resistors. (P/F) The emitter resistor voltages shall be 4.5mVDC (+/-2.0mVDC). [Setup for next test] 4. Initial AC Checks : 4.1. Signal check and gain of amp Setup Signal generator = 260mVAC, 1kHz Signal in = XLR Master pot = max (CW) Output metering = 4ohm out Load = 4ohm Procedure Turn up volume control to full. Watch for irregularities with output. (P/F) Output voltage shall be 21.
FINAL TESTING REQUIREMENTS FOR FINAL TESTING: a) THD meter b) Load 80Ω c) Multimeter d) Oscilloscope e) Microphone f) Variac 5. THD Setup Signal generator = 260mVAC, 1kHz Signal in = XLR Master pot = min (CW) Output metering = 100Vout Load = 80ohm Procedure Turn up master pot to 70VAC (+/-1.0VAC) on output. Measure THD. (P/F) Reading shall be < 0.5%. Values to be recorded: Value 5. 6. THD Pass Range 0% – 0.5% Sensitivity 6.1.
Values to be recorded Value 7a. 7b. 8. Bandwidth - low Bandwidth - high Pass Range <75Hz >20kHz Phase Setup Signal generator = 260mVAC, 1kHz Signal in = XLR Master pot = max (CW) Output metering = 100Vout Load = 80ohm Procedure Attach channel 2 of the CRO to the input. Make sure the CRO is being triggered by the input. Look at each output on channel 1 of the CRO. The CRO ground should be connected to the common both for the low impedance outputs and the line outputs.
Load = 80ohm Procedure Adjust volume pot to an output reading of 70VAC. Connect a thermometer to the temperature sensor. Wait the unit to heat up. A heat gun may be used to speed up the heating of the heatsink. (P/F) The output shall mute to < 10V at a temp between 90–115degC Values to be recorded Value 11b. 12. 13. Thermal cutout Pass Range 90degC – 115degC Final check for damage Disconnect from test bench and inspect for scratches on external paint.
LISTENING TEST REQUIREMENTS FOR LISTENING TEST SETUP: a) CD Player b) mixer c) Speaker 14. Listening Test Connect amplifier to the setup Keep all pots full, tone at center. 14.1. Switch on thump Switch on the set and check for any ON Thump. Ensure unit does not thump. Check that no low frequencies are audible. Make all pots minimum. 14.2. Audio quality Check CD Player output. 14.3. Current Limit Short the output with signal ON. Signal should mute and return.
AMC+ Parts Circuit boards Part Number Factory code Input board Mixer board AMC+30 output board AMC+60 output board AMC120+ mixer board AMC+120 output board AMC+250 output board AMC+IB AMC+120MB AMC+30OPB AMC+60OPB AMC+120MB AMC+120OPB AMC+250OPB B06044 B03048 B06047 B06044 B012046 BR025001 AMC+30TX AMC+30OT AMC+60TX AMC+60OT AMC+120PTX BR0120036 AMC+120OT AMC+250TX AMC+250OT BR0120036 BR030123 BR030124 BD6041 BD060127 BD0642 BR0120036 BR0120125 BR0250140 BR0250141 BR0120036 Transformers AMC+30 mains
Australian Monitor Service Bulletin AMC+ Mixer and Booster Amplifiers Mains Fuses 20 February 2012 Applicable Models This bulletin applies to AMC+30, AMC+60, AMC+120 and AMC+250 Mixer Amplifiers and the AMC+120P, AMC+1202P and AMC+250P Booster Amplifiers manufactured prior to 2012. Known Issue The AMC+ range of mixer amplifiers and AMC+ booster amplifier have experienced a higher than acceptable incidences of mains fuse failures at turn on.