277319 - Service Manual
Contents
1. 60V N o o s z TR13 MJ 15022 N o o s z 35V POUT PGND 35V N o o S Zz TR33 N o o s z CN4 2 560V Zz N mM o OU PCB 9602003 POWER AMPLIFIER BOARD ALL RIGHTS ARE RESERVED NO COPIES OR REPRODUCE THIS DOCUMENT WITHOUT WRITTEN CONSENT BY GENERALMUSIC 08 STEREO BRIDGE PARALLEL DISPLAY SUPPLY CH A CLIP CH A SIGNAL CH A OVERHEATING PROTECT CH B OVERHEATING CH B SIGNAL CH B CLIP DISPLAY DRV DRV DRV DET DET 4 DET DET CTR COLD SH a HOT COLD a N R22 4K7B Li N R23 4K7B Ww IS rb Y Bcs60 R21 m 03 VEL STERE BRIDG PARAL CLIP SIGNA PROTE PROTE SIGNA CLIP BUAR D E LEL A L A CT A CT B L B B PCB 9610036 CKD 1 BATTELLI OSK S8PART 1 1 APP C ZUCCATTI REV 21 10 97 SCHEMATIC DIAGRAM DISPLAY BOARD ALL RIGHTS ARE RESERVED NO COPIES OR REPRODUCE THIS DOCUMENT WITHOUT WRITTEN CONSENT BY GENERALMUSIC Spare Part List Code 277317 667644 667643 667642 667335 657232 340048 238083 177542 141200 130285 110294 110291 080607 778124 768142 140228 768141 110293 110255 100061 070245 070125 042625 042537 030085 768144 768139 090194 080742 080710 080705 074561 768140 110307 110030 110023 110018 090920 090559 090558 0901942. Test point Chassis ground lt __ Flag joined with one or more flags with the same signal name inscribed 10 g2 TECHNICAL SPECIFICATIONS Dimensions WxHxD Weight Power Requirements 230Vac 10 50Hz Output Power 4Q stereo parallel 8Q stereo parallel 8Q bridge 16Q bridge Max Undistorted Out 4Q stereo parallel 8Q bridge Input Sensitivity constant sensitivity constant gain Input Impedance balanced unbalanced Voltage Gain constant sensitivity 8Q stereo parallel constant gain Slew Rate Damping Factor 4Q stereo parallel 8Q stereo parallel Frequency Response 0 2dB at Full Power 3dB IMD SMPTE 60Hz 7KHZz 4 1 THD THD N S N Ratio unweighted Crosstalk 1 KHZ 483x88x325mm 2U 13Kg 500VA 2x 300Watts 2x 200Watts 600Watts 400Watts 98Vpp 113Vpp 194Vpp 0 775Vrms OdB 1 75Vrms 7dB 30KQ 15KQ 33 0 5dB 26 0 5dB 25V uS gt 400 gt 800 20Hz 20KHz 10HZ 60KHz lt 0 1 lt 0 1 gt 95dB gt 60dB TEST PROCEDURES amp ADJUSTMENTS Precaution To prevent short circuit during any test the oscilloscope must be EARTH insulated this occurs because some test require to connect its probe to the amplifier output non compliance may cause damages to oscilloscope inputs circuitry Before removing or installing any modules and connectors disconnect the amplifier from AC MAINS
3. ros CITI EE TN TLS mua Trace C 20V div Trace A 0 5V div Trace B 0 5V div Connect a 2Q 1000W load Increase the input signal the output current limiter must keep the emitter voltages both half channel at 1 25Vp approx see Fig 4 Trace A Temporarily short the amplifier output the current limiter must keep the emitter voltages both half channel at 0 8 0 1Vp see Fig 4 Trace B r r ml Trace B 0 5V div if J mau sma Y u o COOLING FAN amp PROTECTION CHECK Short circuit pins 15 and 16 of OC1 the fan must run at max speed 20 23Vdc on its tips Short circuit pins 13 and 14 of OC1 the PROTECT led must turn on immediately the fan must run at max speed The PROTECT led of the other channel must also turn on after 2 Sec and the relays must discon nect the output sockets Remove the short circuit after 3 Sec both PROTECT leds must turn off Trace A 0 5V div and the relays must re connect the output sockets Temporarily short the emitter and the collector of TR1 the PROTECT led must turn on and the relays must disconnect the output sockets Turn off the amplifier and wait a minute to let the supply caps discharge OFFSET SENSOR CHECK Set the Variac to zero voltage output disconnect the amplifier load and the supply connection to the Power board CN2 3 4 turn on the ampli fier connect temporarily by means of a suitable conductor wire CN3 pin 2 to 15Vdc CN1 pin 5 th
4. 090183 080322 080293 080282 080156 080103 060475 030891 030888 020493 727588 727595 768143 230557 100931 100928 100004 090917 090916 090201 090200 090194 090183 080293 080261 080245 Ref MSSDCR01 MSSDCQ0O1 MSSEBBO1 MEAYA104 HRDKBH51 FIN27341 MEATA102 CONJK351 SWTPR141 FIN27361 FIN27305 CONJK151 CONJK141 FIN27302 service FIN27306 FIN27304 RESVRDO1 FIN27303 CAPELJ81 FIN27311 Description Accessories Owner s Manual P Series Assembly Cover Chassis Front Panel Rear Spacer Level Knob Cord Lock Transformer 500W 230Vac Handle Speakon Socket Mains Cable EU Slider Switch Earth Lift Power Switch KBPC25 25A 200V Rectifier Diode Bridge Cables Assembly Inputs Assemblies Sockets Board Pcb 960301 4 i Horizontal Jack Stereo Socket XLR Female Socket Inputs Board Pcb 9602004 2sw 2pos Slider Switch i 6sw 3pos Vertical Slider Switch i TLO72 Dual J Fet Operational Amplifier replace BA4560 for z 100K 20 Vertical Linear Trimmer 1K 20 Vertical Linear Trimmer 15KO 1 4W 1 Metalized Film Resistor 3K01 1 4w 1 Metalized Film Resistor 2u2 50V 20 Vert Electrolytic Bipolar Capacitor Display Assemblies Led On Off Board Pcb 9610036 Display Board Pcb 9610036 gt BC560 TO92 LN Pnp Transistor Led 3mm Wide Diffused Red Grn Led 3mm 60deg Diffused Yel Led 3mm 60deg Diffused Red dd 4K7 Linear Rotary Potentiometer Supplies am
5. 100925 090920 090919 090918 090917 090916 090910 090907 080820 110359 Note SMCIC831 SMCTR981 SMCTRAO1 SMCTR991 SMCTRA11 SMCTR951 SMCTR961 SMCTR971 SMCTH111 FANDCO51 xx xx xx xx xx xx xx xx xx xx xx xx xx xx 5V6 1W 5 Zener Diode FE6B 6A 100V Fast Recovery Diode 1N4002 1A 100V Rectifier Diode 1N4148 100mA 75V Signal Diode 22K 20 Vertical Linear Trimmer 220E 20 Vertical Linear Trimmer 100E 20 Vertical Linear Trimmer 15K 1W 5 Resistor 8K2 2W 10 Resistor 5K6 2W 10 Resistor 2E7 5W 10 Wire Resistor 0E1 5W 5 Wire Resistor 1000u 6v3 20 Vert Electrolytic Capacitor 10u 25V 20 Vert Electrolytic Bipolar Capacitor TO3 Mica Washer TO126 Mica Washer TO220 Mica Washer TO220 Insulated Bush TO3 Socket LM334 Adjustable Current Source TO92 MJE802 TO126 Npn Darl Transistor MJE15031 TO220 Pnp Transistor MJE15030 TO220 Npn Transistor MJE350 TO126 Pnp Transistor MJE340 TO126 Npn Transistor MJ15023A TO3 Pnp Transistor MJ15022A TO3 Npn Transistor Ptc 80 PTH59F04BF222TS Fan 24Vdc 80x25mm Each spare part is single quantity unless otherwise specified Asterisk prefix explanation First level spare part Omitted One asterisk Two asterisk Three asterisk Any request for not above mentioned part must encompass specific description including 1 Model name 2 Section name 4 Reference name 5 Quantity number 3 Module code Second le
6. 5 El a lt A SH SGND CH B SIGNAL DET 2 5 M 7 m m 1 N C AGND CH B CLIP DET T CN1 Y o 727595 z lt POWER AMPLIFIER BOARD D A CH A OUT BRIDGE OUT CH B OUT CH A SIGNAL A CHANNEL A 1 768142 SOCKETS SEND BOARD CH B SIGNAL A j S JDE G a WZ WI WZ Ter CH B BRIDGE IN SES SES SES LIFT SGND 2 w m Mi EN MN CNA o 9 3 2 1 4 CN2 CN4 M E45 VFAN 22338 2 o z FAN SUPPLY N C FAN lt m m 2 6 I E lt a VFAN ENS a ar A ul Oo U gt s CH A PROTECT SENSE S a 3 U CH A OFFSET DET ME CH B OFFSET DET 15V 3 Bi 7 I Ni IR ws a 15V m A El Ataca BRIDGE IN SIGNAL DET CH A DVERHEATING DET 6 15V CLIP DET SP PROTECT DRV 1 Ll PI a 2 15V PROTECT SENSE CH B DVERHEATING DET 6 SGND OFFSET DET CH A FAN SENSE g AGND FAN SENSE 5 CH B FAN SENSE CNG A LED de CHANNEL B MAINS EUROPE VERSION ON OFF 60V 230VAC 10 6 50Hz A POWER SWITCH T10 ens e o o _e _ PH j nv E MAINS sl 2 T9 e or o e N A POWER TRANSFORMER ey Ea Ti CN7 CN10 RED 6 3 VAC2 PH YELLDW 2 VAC1 CNG POWER 2 PGND A L TRANSFORMER prev YELLOW 3 ca a LLL ss PGND 758140 POWER SUPPLIES PROTECTIONS BOARD CKD I BATTELLI DSK S8PART 1 1 SCHEMATIC DIAGRAM ALL RIGHTS ARE RESERVED NO COPIES OR REPRODUCE THIS DOCUMENT WITHOUT CH A LEVEL nm
7. Brose SEK 1N4002 g gt 3 G i o lt o gt LED ON I uj al mr a lt E E 6 lt m O gt AGND a u m S N FAN SENSE z z z D O U O O VFAN N o S FAN SUPPLY z VFAN vt o o M M o o u w j 1 PCB 9602002 m m J o a O D EARTH LIFT SOCKETS BOARDO O E lt O M U LL gt U O U CKD 1 BATTELLI DSK S8 PART 1 1 SCHEMATIC DIAGRAM ALL RIGHTS ARE RESERVED NO COPIES v 03NNYHA 8 13NNYHA EKD 1 BATTELLI SCHEMATIC DIAGRAM cer Tons TE ARE RESERVED ND COPIES APP C ZUCCATTI REV 21 10 97 BOARD WRITTEN CONSENT BY GENERALMUSIC FAN SENSE PROTECT SENSE 15V SGND 15V BRIDGE IN SIGNAL IN SGND CLIP DET AGND SIGNAL DET OFFSET DET NOTE z es 1N4148 1N4148 1N4148 IN CASE OF SOA ADJUSTMENT MISBEHAVIOUR WITH NEW ONE WITH HIGHER VALUE VOLTAGE PUWER AW i kA l TA 2N5550 1N4148 1N4148 D6 1N4148 D7 D8 1N4148 68K L 4K7 R15 L TRS 2N5401 TRY TO REPLACE D13 ZENER DIODE BUARD DC1 A TLPS21 DC1 D TLPS21 TR8 1N4002 D11 1N4002 C13 IC3 LM334 TR15 on L 1N4002 1N4148 7V5 TP3 1N4002 a TR14 D18 o ca 1N4002 PTCBOC 1N4148 1N4002 1N4002 4E7 1 72W 1N4002 D34 1N4002 1N4002 56K 7 010681 47N D35 15K 1W ae
8. and measure the DC supply voltages across each of the power suppliy capacitors If your measurement on any of the caps is greater than 10Vdc connect a 10092 20W resistor across the applicable caps to discharge them for your safety Remember to remove the discharge resistor immediately after discharging caps Do not power up the amplifier with the discharge resistor connected Read these notes entirely before proceeding to any operation These notes are not comprehensive of all damages that possibly occur but includes some specifically advices checks and adjustments relative to this amplifier Remarks gt The power supply utilizes a dual bipolar DC rail configuration with low and high voltages one positive and one negative low rail Vcc1 and one positive and one negative high rail Vcc2 Visual Check Use compressed air to clear dust in the amplifier chassis Before proceed to supply the amplifier check visually the internal assem bly if appears an evident damage find the most possible reasons that cause it Check the wiring cables for possible interruptions or shorts Ifthe damage has burnt a printed circuit board don t try to repair it re place with a new one Test Instruments Audio Generator Dual Trace Oscilloscope 2 Digital Multimeter 20 1000W 49 500W 1000 20W resistors Variac 0 250Vac Temperature Meter Setup Connect the Variac between the mains and the ampli
9. NSITIVITY switch check the output levels at 775mV position the output voltage must be 50 1 5Vp _ gt _ Es OUTPUTS INPUTS and at 1 75V position must be 22 5 0 5Vp WARNING ro Rebuce THE O CH B CH A O CEJ CH A gt AMPLIFIER BRIDGE MODE CHECK O mai ac ad MIN LOAD 40 MIN LOAD 80 MIN LOAD 4Q O O Set the amplifier in BRIDGE mode input signal to channel A connect ES A ox VO the CH2 probe to the bridge output the output voltage must be 97 3Vp e MA gt SIGNAL TO NOISE RATIO CHECK ae ac l l l by GENERAEMUSIC DL O BALANCED BALANCED Disconnect the audio generator and short the input pin 1 2 3 of XLR O PIN 1 SON socket shorted the output signal noise must be less 1mV a A A A P500 O WARNING O O gt Lem MAKE PROPER SPEAKERS CONNECNONS PROFESSIONAL bo zi O hy GENERALMUSIC REFER TO OWNERS MANUAL BEFORE USING POWER AMPLIFIER Advices Check the channels one at time to determine which is right note if you have a spare amplifier module that you know as right use it If you have determinate that the problem is a short on a rail you must check the output transistors To determine which transistor devices are bad use a soldering iron to lift one leg of each emitter pin and measure the emitter collector resistance on each device Unsolder and lift one leg of each base pin and check the base collector resistance of each transistor and replace any that m
10. P500 PROFESSIONAL POWER AMPLIFIER Technical Specifications Test Procedures amp Adjustments Layout Wiring Connections Inputs Board Supplies amp Protections Board Power Amplifier Board Display Board amp Part List CGEINERAMLACS PA Siles D sion 473 22 S C sO _ rr inNaigao Ay MAY VacGHle Rose L2 ta DAV IBN Y x550 E5 CBA HCI f amp lt O F 95 7104 Nii ce Service must be carried out by qualified personnel only Any tampering carried out by unqualified personnel during the guarantee period will forfeit the right to guarantee For a correct operation of the instrument after having switched off be careful to wait at least 3 seconds before switching on again To improve the device s specifications the schematic diagrams may be subject to change without prior notice SOrenah C Ndes he components marked by this symbol have special safety characteristics when replacing any of these components use only manufacturer s specified parts The u micro symbol of capacitance value is substituted by U The Q omega symbol of resistance value is substituted by E The electrolytic capacitors are 25Vdc rated voltage unless otherwise specified All resistors are 1 4W unless otherwise specified lt Soldering point 4 Supply voltage e Male connector a Logic supply ground IF t Anal d A pi Bl gt Og SAPPY OUN Observe precautions when handling lt M F faston connector Y Signal ground electrostatic sensitive devices
11. W 5 den 53 8532 lt gt r s u W Z o uw lt 238 ajo o ea lt al era I 4 Ww lt lt U 5 u Z z O z a u o m TG m 5 5 2355 s gt e ds 68140 lt gt m gt m m ars mn Z tn 25 I o I I E 3 5 POWER SUPPLIES amp PRUE TONS BOARD A F5 e E N o E o PH 2 2 2 S 2 o n lt POWER D u D U O FROM POWER SWITCH Z gt n T oo TRANSFORMER on o En U m N e gt lt 5 a o UL lt Z s hh eH S o 60V N o o m s b b m gt x u u oo Llon 35V lt gt gt ln ol m 2 o o a u g in 2 VAC2 w o u o u lt o nia Z S F SHE Mm oye vaci H S POWER 2 PGND alale TRANSFORMER CENTER TAP Y me m Tyaye vaci gt 2 D E o 2 M 3 lt D VAC2 O o o U o SGNO G o o z lt 5 o mo n mo lo lo m N O zl lu sl x ol lt 35V HS HS g ZNJ 010 0107 J Z ZNI u A HL yl u 60V 10H 10H m S ZNO O m 15V N o lt LED ON GND w DISPLAY GND Sjo s o O a 15V Ng M a o CN1 2 CH A POUT CN1 1 CH A OUT CN1 3 CH B POUT CN1 4 CH B OUT 23V 23V pd N R18 CN3 1 x TRS T OFFSET DET lt D N O S z o o S M o 23V z U U m mr PROTECT SENSE TR2 MJE803 a 10K 1N4148 BC550 x x S 8 w N o ole Z u lt js U CN2 5 ai OVERHEAT DET 184148 PRDTECT DRV gt DISPLAY SUPPLY a z gt 5 TR7 s
12. an 30Vp the voltage on D20 cathode must remain constant at 36V when the output signal exceeds 30Vp the voltage must follow the output signal with 6V offset see Fig 1 Trace B to check the negative high rail connect the probe to D30 anode see Fig 1 Trace C Connect the 4Q 500W load on the output and repeat the INITIAL and HIGH RAIL checks Check the signal clipping it must occur at 48 2Vpp see Fig 2 Trace A B C ror j SA Trace B 20V div Trace A 20V div LA 4 Trace C 20V div MITTS Fig 2 Ig eee Trace B 20V div i t I Trace A 20V div TN HACE YEN i HA Verify the voltages across the diodes D19 and D26 they must be 14 8 079 V dC SIGNAL CLIP SENSOR CHECK Set the LEVEL pot to minimum set the scope timebase at 1V div 200uS div then increase the level and check the SIGNAL CLIP led activity it must turn on green light when the amplifier output is higher than 1Vp Set the scope at 20V div and increase the level check the led it must change from green to red colour at the amplifier output signal clipping CURRENT AND SHORT CIRCUIT SENSOR CHECK Set the CH2 sensitivity to 0 5V div connect the scope CH1 GND clip at CN3 pin 2 AMP output and the probe tip at TR26 PNP emitter con nect the CH2 probe tip at TR17 NPN emitter Set the generator to have approx 1Vp on the emitters their difference must be less than 0 2V on the peaks see Fig 3 Trace A amp B
13. e PROTECT led must turn on in 5 seconds approx the fan must run at maximum speed Remove the connection wait until the leds turn off and after some sec onds repeat the check with 15Vdc available on CN1 pin 4 the led PROTECT must turn on again SOA ADJUSTMENT Set the scope sensitivity at 5V div both channels Disconnect the fan and cut the pins A B of J16 Connect the 4Q 500W load and connect the CH2 probe tip at TR23 collector check the waveform as shown in Fig 5 Trace B Trace A show CH1 that is also connected at TR26 PNP emitter de TTT ttt TT MENE ty aus Set the scope CH2 sensitivity at 2V div and connect the probe tip at the testpoint TP3 Set the load at 2Q wait until the temperature reaches 80 C then change the load back to 40 Adjust the generator level to have the CH1 waveshape as shown in Fig 6 Trace A Turn the R47 trimmer to level the peaks of the CH2 waveshape as shown Fig 6 Trace b oe TET TT TT TTT Ksa pete HH hw TN 982 Solder the pins A B of J16 the CH2 trace becomes continuous Increase the generator level for the max displacement of the CH2 trace toward the centre of the screen Fig 7 Trace b Wait until the temperature reaches 88 C then turn clockwise the R62 trimmer to activate the SOA control that is displayed by CH1 trace when its peak voltage decrease Fig 7 Trace A after some seconds the chan nel goes in PROTECT mode Set the CH2 sensitivity at 5V d
14. easure as a short If all the transistors are OK unsolder and lift one leg of each diode and check them Check the circuit board for open foil traces Use the Multimeter as Ohm meter to check the resistors particularly the base and emitter resistors of damaged transistor If the input sinewave appears to be distorted during the negative cycle you can assume that the problem is located somewhere in the circuitry of the positive low rail O If the positive cycle appears distorted you can assume that the problem is in the circuitry of the negative low rail Ifthe high rails appear distorted or are not modulating as shown in figure then the problem probably exists somewhere in the circuitry of the respec tive or defective high rail Refer to the schematics 768141 INPUTS BOARD CN1 STEREO DRV I STERED DRV 7681 33 S JISPLA BOARD BRIDGE DRV 12 BRIDGE DRV PARALLEL DRV a PARALLEL DRV DISPLAY SUPPLY s DISPLAY SUPPLY 2 768142 SOCKETS DISPLAY GND BDARD V S CN2 3 A II L lt oe T ME CTR CN N Ch A LEVEL ACE Ch A LEVEL Z H H 5 COLD Q SIGNAL IN SIGNAL DET CH A SIGNAL DET lt U 5 AN a1 SH SGND CLIP DET SP CH A CLIP DET gt a E E HOT BRIDGE IN PROTECT SENSE sk CH A DVERHEATING DET z 10 6 CTR 15V OFFSET DET PROTECT DRV a CH B LEVEL NN gt CH B LEVEL u COLD 15V FAN SENSE CH B OVERHEATING DET z
15. fier and set it at zero voltage Set the amplifier in STEREO MODE and turn full clockwise the LEVEL potentiometers Connect the audio generator to the channel inputs and set it to 1KHz 775MVems OdB sinusoidal signal Insert the temperature meter through the IC3 interstice located at centre of heatsink The procedures that follow must be executed subsequently in the order specified Supply Check gt Remove the transformer secondary fuses located on SUPPLY amp PRO TECTIONS board set the Variac to the nominal mains voltage check with the Multimeter the AC supply voltages F1 F2 52 2Vac F3 F4 90 3Vac Re set the Variac at zero voltage turn off the amplifier and put the fuses back on its holders Connect the oscilloscope probes CH1 2 to the channel outputs before RL1 and RL2 set both to 20V div 200uS div Set up the Variac slowly monitoring the Outputs with the oscilloscope CH1 2 connected it should display the sinusoidal input signal amplified with no distortions if a distortion occur check the POWER AMPLIFIER boards as suggested in the ADVICES section If the protection trips turn off the amplifier wait some minutes and disconnect the supplies from the outputs modules CN2 CN3 on POWER AMPLIFIER boards continue to check the supplies CAUTION Before re connecting the output modules to the supplies you must have the capacitors discharged for your safety connect a 100Q 20W resistor across the ca
16. iv then with its tip check the voltage on D19 cathode it must be 14V or more Activate the fan and check its supply voltage it must be 20V or more max speed Trace A 5V div Trace B 5V div Trace A 5V div Trace B 2V div Fig 7 muma PES BEBA Trace A 5V div Trace B 2V div BIAS ADJUSTMENT Remove the CH2 probe connect CH1 GND clip to CN3 pin 1 GND terminal and its probe tip to CN3 pin 2 AMP output and set its sensitiv ity at 1V div Set the generator level at zero connect the Multimeter across the emit ters of TR17 and TR26 when the heatsink temperature reaches 55 C turn off the cooling fan and adjust R55 trimmer to read 6 0 5mV Adjust the generator level until the sinewave appears at full screen ampli tude No crossover distortion must be detectable if necessary re adjust R55 Re connect the fan gt BANDWIDTH CHECK Sweep the generator frequency from 20Hz to 20KHz the output level must have not detectable level changes SLEW RATE CHECK Set the scope sensitivity to 10V div 1uS div and set the generator to 1KHz square wave mode Check the output square wave rising and falling edge slopes both must be 10V uS or more as shown in Fig 8 Fig 8 Ey Ann TA Zee fii RERAN li Trace A 10V div Inputs Board Check These procedures are intended for one channel at a time repeat these opera
17. p Protections Assembly Power Supplies amp Protections Board Pcb 9602002 3 Relay 24V 2 Switch 5A 250V T10A Fuse 5x20mm EU id T8A Fuse 5x20mm EU id T6 3A Fuse 5x20mm EU MJE802 TO126 Npn Darl Transistor TIP122 TO220 Npn Darlington Transistor j TIP127 TO220 Pnp Darlington Transistor BC560 TO92 LN Pnp Transistor i BC550 TO92 LN Npn Transistor la 24V 1W 5 Zener Diode 15V 1W 5 Zener Diode 13V 1W 5 Zener Diode 1N4002 1A 100V Rectifier Diode 1N4148 100mA 75V Signal Diode 680E 2W 10 Resistor x 10000u 63V 10 50 Vert Electrolytic Capacitor FS i 10000u 80v 10 50 V Electrolytic Capacitor FS 100n 250Vac MKP EMI Capacitor Siemens Power Channels Assembly Dual Power Amplifier Board Pcb 9602003 si Power Amplifier Board Pcb 9602003 with Heatsink Power Amplifier Board Pcb 9602003 without Heatsink quh Horizontal Coil For Amplifier MC34081 Single J Fet Operational Amplifier TLP521 4 Quad Optocoupler LM3080 Operational Transconductance Amp MJE350 TO126 Pnp Transistor MJE340 TO126 Npn Transistor 2N5401 TO92 Pnp Transistor 2N5550 TO92 Npn Transistor BC560 TO92 LN Pnp Transistor BC550 TO92 LN Npn Transistor 15V 1W 5 Zener Diode 10V 1W 5 Zener Diode 7V5 1W 5 Zener Diode 080241 080171 080156 080103 070207 070084 070065 060620 060591 060571 060174 060033 030715 030247 340752 340750 340079 340078 140626
18. ps and remove the resistor just after they are discharged Finally verify the DC supplies on SUPPLIES amp PROTECTIONS Board 18 Vcc2 61 2Vdc T5 Vcc1 35 1 5Vdc T6 Vcc1 35 1 5Vdc T7 Vcc2 61 2Vdc CN2 pint 23 1Vdc CNS pin3 4 5 15 1Vdc CNS pin8 9 10 15 1Vdc If one or more voltages don t correspond check the rectifiers capacitors and transformers disconnecting them from circuitry refer to schematics Channels Check The channel A is facing the front and channel B the rear of the chassis These procedures are intended for one channel at a time repeat these operation for the other channel Verify with the Multimeter the insulation between the heatsink and the transistors collectors gt SETUP Connect the CH1 scope GND clip to CN3 pin 1 GND terminal Connect the CH1 probe tip to CNS pin 2 AMP output Connect the CH2 probe tip to D20 cathode Set the LEVEL potentiometers full clockwise The load resistor is disconnected gt INITIAL TEST Increase slowly the Variac The channel output signals must be symmetri cal respect the GND without visible distortion and oscillation as shown in Fig 1 Trace A If there is a distortion read the section ADVICES and proceed to check the other channel Verify that when the heatsink temperature is less than 50 c the cooling fan voltage must be between 10 and 14Vdc gt HIGH RAIL CHECK When the output signal Positive half wave is less th
19. tions for the other channel gt SETUP Connect the CH1 probe to amplifier input of the channel under test and set both at 500mV div 200mS div Connect the CH2 probe to amplifier output of the channel under test and set it at 10mV div 200mS div Set the audio generator at 1KHz sinus 775mMVams OdB Set the LEVEL potentiometers full clockwise The load resistor is disconnected CMRR ADJUSTMENT Temporarily disconnect pin 3 from pin 1 and short the pin 2 positive input and pin 3 negative input of XLR input socket Adjust the trimmer R10 channel A or R21 channel B to obtain the minimum output level 30 gt GAIN ADJUSTMENT Set CH2 scope at 500mV div and connect it to the output of INPUTS by GENERALMUSIC Re set the input signal at pin 2 positive input and pin 3 negative input SUD ra STEREO BRIDGE PARALLEL ON short with pin 1 GND of XLR input socket S 2 gt LETT v O board CN3 pin9 for channel A or CN3 pin for channel B Re pee anur Set the input SENSITIVITY SW1 at 1 75Vrms adjust the trimmer R5 O PROTECT PROTECT O channel A or R17 channel B to obtain the same amplitude of the O scope signals Noro ifi SUL PSUU PROFESSIONAL POWER AMPLIFIER didas Set CH2 scope at 20V div and connect it to the amplifier output of the Na O channel under test By means of the SE
20. vel part of previous listed first level part Third level part of previous listed second level part
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