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1、C2500 SERVICE MANUAL Performance Specifications .2 Notes .3 Rear Panel .4 Section Location .4 Block Diagram .5 - 6 Interconnection Diagram .7 - 8 Display Schematic and PCB.9 - 18 Control Schematic and PCB .19 - 30 Audio Schematic and PCB .31 - 42 Balanced I/O Schematic and PCB .43 - 46 Digital Audio
2、 Schematic and PCB .47 - 54 Backup PS Schematic and PCB .55 - 58 Power Schematic and PCB .59 - 62 Tube Schematic and PCB .63 - 70 Audio Expansion Schematic and PCB .71 - 74 Meter Light Schematic and PCB .75 - 76 Parts List .77 - 92 Repacking Instruction .93 CONTENTS TUBE PREAMPLIFIER SERIAL NO. ADF1
3、001 And Above C2500 PRELIMINARY RadioFans.CN 收音机爱 好者资料库 PERFORMANCE SPECIFICATIONS 2 Specifications Frequency Response +0, -0.5dB from 20Hz to 20,000Hz +0, -3dB from 10Hz to 100,000Hz Total Harmonic Distortion 0.08% from 20Hz to 20,000Hz Rated Output (Main) 2.5V Unbalanced, 5V Balanced Maximum Outpu
4、t 8V RMS Unbalanced, 16V RMS Balanced Sensitivity (for rated output) High Level, 450mV unbalanced, 900mV balanced Phono MM, 4.5mV Phono MC, 0.45mV Signal To Noise Ratio (A-Weighted) High Level, 100dB below rated output Phono MM, 75dB below 5mV input Phono MC, 75dB below 0.5mV input Input Impedance H
5、igh Level, 22K ohms unbalanced, 44k ohms balanced Phono MM, 47K ohms; 50 to 750pF, in 50pF steps Phono MC, 25, 50, 100, 200, 400 or 1,000 ohms; 100pF Maximum Input Signal High Level, 8V Unbalanced, 16V Balanced Phono MM, 80mV Phono MC, 8mV Voltage Gain High Level to Record Output: 0dB High Level to
6、Main Output: 15dB Phono MM to Record Output: 40dB Phono MC to Record Output: 60dB Output Impedance 220 ohms Headphone Impedance 20 ohms to 600 ohms Digital Input Sample Rates Optical: 16Bit, 24Bit - 32kHz to 96kHz Coaxial: 16Bit, 24Bit - 32kHz to 96kHz USB: 16Bit, 24Bit, 32Bit - 32kHz to 192kHz Powe
7、r Control and Trigger Output 12VDC, 25mA Power Requirements Field AC Voltage conversion of the C2500 is not possible. The C2500 is factory configured for one of the following AC Voltages: 100 Volts, 50/60Hz at 50 watts 110 Volts, 50/60Hz at 50 watts 120 Volts, 50/60Hz at 50 watts 220 Volts, 50/60Hz
8、at 50 watts 230 Volts, 50/60Hz at 50 watts 240 Volts, 50/60Hz at 50 watts Standby Power, less than 0.5 watts Note: Refer to the rear panel of the C2500 for the correct voltage. Overall Dimensions Width is 17-1/2 inches (44.45cm) Height is 7-5/8 inches (19.37cm) including feet Depth is 18 inches (45.
9、72cm) including the Front Panel, Knobs and Cables Weight 30.5 pounds (13.8 kg) net, 46 pounds (20.9 kg) in shipping carton Shipping Carton Dimensions Width is 27 inches (68.6cm) Height is 14 inches (35.6cm) Depth is 25 inches (63.5cm) NOTES RadioFans.CN 收音机爱 好者资料库 C2500 3 REAR PANEL RadioFans.CN 收音机
10、爱 好者资料库 4 SECTION LOCATIONS TOP VIEW WITH COVER REMOVED BOTTOM VIEW WITH COVER REMOVED 2 DISPLAY PCB 3 CONTROL PCB 6 DIGITAL AUDIO PCB 7 BACKUP PS PCB 8 POWER PCB 4 AUDIO PCB TUBE PCB 9 AUDIO EXPANSION PCB 10 BALANCED I/O PCB 5 METER LIGHT PCB 11 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 BLOCK
11、 DIAGRAM 56 RadioFans.CN 收音机爱 好者资料库 78 INTERCONNECT 10 TUBE 18 J5 J6J4 J1J2 J7 J23J24 J26 CA24 CA25 CA18 J46 J41 J20 J16 J1 J1 CA26 J4 CA27 V1 L1 J22 CA12 CA28 CA17 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 910 2 DISPLAY 751456 SCH 1 OF 4 GND (Pin 1) 5V (Pin 2) SI/SO (Pin 3) STB (Pin 4) SCK (P
12、in 6) .01FC207 .01FC206 DGND DGND VFD-GND INPUT_B INPUT_A 22.1 R11 47F C1 IR SENSOR 2 1 3 Vcc Vout GND MT1 .1F C2 1K R45 3.3V 22.1KR29 22.1K R30 22.1KR28 22.1KR34 3.3V BU J9:18 J9:15 J9:12 J9:16 J9:17 J9:13 J9:10 J9:11 J9:14 J9:9 J9:6 J9:3 J9:4 J9:5 J9:7 J9:1 J9:8 J9:2 INPUT_A INPUT_B LEFT PB AD VFD
13、 5V VFD SCL VFD SDA VFD CE VFD CE FRONT_IR I2C_SCL I2C_SDA VFD 5V VFD SDA VFD SCL .1FC6 DGND 3.3V .1FC7 DGND 3.3V 3.3V BU BYPASS PROC DS23 DS24 DS18 STANDBY/ON MH2 ADC-VREF-L 3.3V VFD 5V TRIM DS17 750932 = 058195 + 9 pin conn (117986) 4 2 1 3 Vcc GND 5 U4 4 2 1 3 Vcc GND 5 U5 SELECTOR INPUT 5V GND 6
14、 B 1 C 4 A 5 GND 7 S1 146261 ILLUMINATION FRONT PANEL DS6DS4 3 1 2 Q1 150 R14 150 R19 DS2 2.21K R16 150 R15 PANEL_LAMP Q3 7 VSS 8 Q1 5 A1 2 A2 3 Q4 9 Q5 10 Q7 12 SDA 15 SCL 14 Q2 6 A0 1 Q0 4 Q6 11 VDD 16 NC 13 U30 22.1KR202 22.1KR201 22.1KR210 22.1KR209 3.3V BU 22.1 R211 22.1R212 22.1KR203 22.1K R20
15、4 1K R220 1K R213 1K R214 1K R216 1K R218 Address=3 .1F C80 OFF ON OFF ON OFF ON OFF ON 3.3V BU I2C_SDA I2C_SCL 5V DS7 150 R2 DS8 150 R1 DS9 OUT1DS10OUT2 3.3V 3.3V 3.3V 3.3V3.3V PANEL_LAMP 3.3V BU .1F C66 4 2 1 35 Vcc GND U25 47F C18 .1F C19 10H L1 47F C23 VOL-B VOL-A OFF ON 22.1 R69 22.1 R70 SDA (S
16、I/SO) CE (STB) SCL (SCK) J1:2J1:7J1:1J1:5J1:4J1:6J1:9J1:3J1:8 Daughter PCB J12:12J12:11 J12:10J12:9 J12:8J12:7 J12:6J12:5 J12:4J12:3 J12:2J12:1 J11:12J11:11 J11:10 J11:9 J11:8 J11:7 J11:6 J11:5 J11:4J11:3 J11:2J11:1 B A 179 46 12 Ground J13:4 MH1 052139 (146260) J13:3 J13:2 J13:1 CONTROL VOLUME MH12
17、 MH9 METER LEDs ON METER MUTE .1F C8 3.3V 4 2 1 3 Vcc GND 5 U6 3.3V BU .1F C9 4 2 1 35 Vcc GND U7 22.1 R8 J7:1 J7:2 J7:3 J7:4 J7:5 J7:6 J7:7 J7:8 J7:9 J7:10 J7:11 J7:12 3.3V BU VOL-B ON/RESET 5V 5V ADC-VREF-R RIGHT PB AD VOL-A 3.3V FRONT_IR SP1 -15V 15V To Control PCB 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3
18、 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 1 J17 J16:1 J16:2 J16:5 .1F C119 MP2MP1 GP1 J16:4 Tip Ring GND Cable 173167, 1-1 Pinout. Headphone daughter PCB 2X20 VFD ASSY Left PB Right PB VolumeLogoInput DS1 RadioFans.CN 收音机爱 好者资料库 1112 2 DISPLAY 751456 SCH 2 OF 4 0V 0V 0V 0V 0V .3V -.5V -3.7V 0V 0V 1 1 1 0V 0V
19、 0V .3V -.5V 1 0V 0V LEFT -3.7V LEFT -3.7V -3.7V 1K R115 LEFT METER DRIVER LEFT METER RIGHT - RIGHT + LEFT - J22:2 RIGHT LEFT 47F C5 RIGHT .1F C64 1K R94 47F C65 D14 220F C69 D6 D7 D11 RIGHT D10 D9 D13 D12 3 1 2 Q39 METER DRIVER 1K R114 LEFT J23:1 J23:2 LEFT + J22:1 47 R95 D8 3 1 2 Q40 2.21M R110 2.
20、21M R111 3 1 2 Q44 3 1 2 Q43 3 1 2 Q45 3 1 2 Q46 RIGHT METER METER BUFFER LEFT METER LOG CONVERTER METER BUFFER METER RECTIFIER .1F C71 RIGHT METER METERS ON/OFF CONTROL D5 100K R99 LOG CONVERTER 1K R97 2 3 1 84 B+ B- U10:1 .1F C67 .1F C68 6 5 7 U11:2 D3 100K R98 1K R96 .47F C72 .1F C73 150K R105 22
21、.1K R101 .47F C70 221 R108 METER RECTIFIER 150K R103 22.1K R100 METERS ON/OFF CONTROL D4 6 5 7 U12:2 D2 6 5 7 U10:2 221 R109 3 1 2 Q42 2 3 1 84 B+ B- U12:1 3 1 2 Q41 2 3 1 84 B+ B- U11:1 10K R116 10K R117 -5V 10V 10V-5V -5V 10V 10V -5V 2.21 R113 15K R38 D30 2.21 R112 15K R37 1K R249 1KR250 .01F C170
22、 .01F C169 221K R251 221K R252 10V -5V R76 R77 (806 ohm) (806 ohm) J4:1 J4:2 J4:3 J4:4 R-METER L-METER TO AUDIO PCB CABLE 173081, PIN1-1 GND GND L METER R METER R-METER L-METER J41:1 J41:2 J41:3 J41:4 METER MUTE 100K R3 100K R4 15V -15V 15V -15V 5k 13 2 CCW R106 5k 13 2 CCW R107 10 10 10 10 OPEN R40
23、0 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 1314 2 DISPLAY 751456 SCH 3 OF 4 5V 5V 5V 12L 12L 12L 12R 12R 12R 5V 12L 12R TO LEFT METER LIGHT BLU 3 1 2 Q2 GRN METER ILLUMINATION 2.21K R71 1k 13 2 CCW R74 500 13 2 CCW R73 1k 13 2 CCW R72 500 13 2 CCW R75 J14:4 J15:4 J15:2 J14:7 J14:11 J14:1 J15:
24、11 J15:7 J14:6 J14:12 J15:1 J14:9 J14:8 J15:12 J14:2 J14:5 12R 5V 5V 12R J15:5 J15:6 J15:8 J15:9 5V 5V TO RIGHT METER LIGHT DRIVER GRN GRN 5V 5V BLU BLU BLU BLU BLU GRN GRN GRN METER LEDs ON 12R 12R 12R 12R 12L 12L 12L 12L 12L 12L RadioFans.CN 收音机爱 好者资料库 1516 2 DISPLAY 751456 SCH 4 OF 4 MUTE OUT1 OU
25、T2 Standby/On/Reset Button Common 3 2 1 + - 84 B+ B- U1:1 5 6 7 + - U1:2 3 1 2 Q5 10K R58 22.1K R51 ON Button + 100 R12 ON/RESET LEFT PB AD This Transister buffers the Standby button for the A/D matrix 10F C3 .1F C4 Vout LT Vout LT ADC-VREF-L 10K R55 10K R46 10K R53 BYPASS PROC TRIM MH3 Chassis h ol
26、e f or Sp ark Grou nd 3.3V BU Left Pushbutton A/D Buffer To Right Pushbutton PCB To Left Pushbutton PCB SPARK GND-L 2 2 2 2 2 2 2 2 2 J2:1J2:5J2:3J2:4J2:6J2:2J2:10J2:7J2:12J2:11J2:8J2:9 2 2 2 1A 1B 2A 2B Spark Ground Spark Ground 4A 3B 2 4B Spark Ground Spark Ground Button Common Vout RT ADC-VREF-R
27、10K R57 10K R13 10K R47 10K R7 Chassis hole for Spark Ground SPARK GND-R 2 2 2 2 2 2 2 2 2 J3:1J3:5J3:3J3:4J3:6J3:2J3:10J3:7J3:12J3:11J3:8J3:9 2 2 2 1A 1B 2A 2B Spark Ground Spark Ground 4A 3B 2 4B Spark Ground Spark Ground To Push Input Slave, Output Master Pin 19 SAIF; Input: I2S up to 32-Bit Pin
28、18 SAOF; Output: I2S 32-Bit Data NC SP10 RadioFans.CN 收音机爱 好者资料库 5152 6 DIGITAL AUDIO 751120 SCH 3 of 3 1.82K R9 10uF C36 10uF C22 475 R27 .0022uF C10 .1uF C37 22.1K R30 100uHL2 133757TI PCM1795DB 12 13 10 7 8 5 2 3 17 16 19 22 21 24 27 26 9 11 14 1 4 6 20 18 15 28 25 23 MC MDO VDD MS DGND SCL PDATA
29、 ZEROR MSEL IREF MDI RST ZEROL BCK VCC2R AGND3R IOUTR+ AGND1 VCOMR VCOML AGND2 IOUTL+ IOUTL- AGND3L IOUTR- VCC1 VCC2L LRCK U6 2 3 1 - + 84 B+ B- U8:1 -15V-OP 15V-OP -15V-OP -14.5V-OP 2 3 1 - + 84 B+ B- U4:1 6 5 7 - + U4:2 1000pF C3 475 R4 15V-OP -14.5V-OP 220uF C7 100uHL3 22.1R16 22.1R18 22.1R19 22.
30、1R22 22.1R25 22.1R26 47.5KR28 .1uFC16 .1uFC5 .1uFC9 .1uF C26 .1uF C27 10KR23 1000pFC13 6 5 7 - + U8:2 1K R24 .0022uF C15 2.21K R32 .1uF C40 1.82K R14 1.5K R6 330pF C4 1.5K R17 475 R20 1000pFC23 1.5K R8 1.5K R13 3 1 2 Q3 1K R37 3 1 2 Q6 1K R40 22.1K R41 3 1 2 Q4 1.82K R61 .0022uF C35 6 5 7 - + U10:2
31、-14.5V-OP 15V-OP 1000pFC33 475 R57 -14.5V-OP 15V-OP 1000pF C41 1K R55 1.82K R65 1.5K R59 330pF C34 1.5K R68 475 R69 1.5K R60 1.5K R64 10uF C28 475 R53 22.1K R54 2 3 1 - + 84 B+ B- U10:1 2.21K R51 1000pFC29 .0022uF C30 330pF C38 330pF C12 2 3 1 - + 84 B+ B- U9:1 6 5 7 - + U9:2 22.1 R67 22.1 R63 DA-L
32、DA-R 10K R38 10uF C39 10uFC6 10uFC8 47uFC11 47uFC14 SP3 SP2 332 R5 332 R21 332 R58 332 R70 1.82K R62 1.82K R66 1.82K R15 1.82K R10 RST 4 2 1 3 Vcc GND 5 U2 PLRCK PBCK SYS-CLK 22.1R7 DA AUDIO MUTE L6 .1uF C69 PDATA 22.1R79 3.3V 5VD TO AUDIO PCB J10:1 J10:3 DA-L DA-R J3:12 J3:10 ADDR-1 ADDR-0 SCL SDA
33、-15V 15V -15.4V DA RESET/ SDA SCL GND 2 E/D 1 OUT 3 VDD 4 Y5 10uFC105 .1uFC104 3.24V 100K R174 12 L14 OPEN R173 SYS-CLK J10:5 J10:7 0 R176 4 4 4 4 5VD 5VD CONV UNLOCKED Unlocked Good Signal Unmuted Muted L L = H L H = L H L = L H H = L Unmuted Muted Unmuted Muted LED4 22.1K R181 47.5K R182 ON = Audi
34、o Out DA Run DA Reset OPENR186 OPENR187 3.24V 3.24V 0V 1.65V 0V 0V 0V 0V 0V 0V 0V 0V -2.75V -2.75V -2.75V -2.75V -1.38V -1.38V 0V -1.38V -1.38V 0V0V 0V 0V 0V 0V 0V 0V 4.5V 5V 5.1V .77V .77V 0V 0V 0V 0V J3:6 J3:8 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 5354 6 DIGITAL AUDIO 751120 PCB RadioFan
35、s.CN 收音机爱 好者资料库 5556 7 BACKUP PS 751185 SCH 1 1 1 GRY BLU BLK 300mA t R1 D3 D4 D2 D5 1 1 1 WHT ORG VIO 1 1 AC N AC LINE 7 7 7 7 7 D1 J5:2 J5:1 3 POWER RLY 2 6 8 4 1 3 5 7 PRIMARY T1 +VBU GND J5:3 +VBU +VBU 7 300mA t R2 3300uF C1 J6:1 J6:2 + TP - TEST ONLY NO CONNECTION J4:4 J4:3 J4:5 J4:2 J4:1 J4:6
36、F1 3300uF C2 AC LINE FILTER N L G 16 2 54 3 K1 ! ! ! ! ! ! ! J1:3 J1:2 J1:1 J1:4 J1:5 J1:6 ! VOLTAGE SELECTION JUMPERS 240V 220V 120V 100V 100V 120V 230V 110V 110V POWER TRANSFORMER PRIMARY ! J2:1 J2:2 3 3 100V 50/60Hz 110-120V 50/60Hz 089141 T800mAL 220-240V 50/60Hz 089126 T500mAL 089132 T1AL T1 TO
37、 CONTROL PCB J24:3 J24:2 J24:1 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 5758 7 BACKUP PS 751185 PCB RadioFans.CN 收音机爱 好者资料库 5960 8 POWER 751459 SCH 15 14 T1 T1 ORG ORG 177V 18V 165V 131V 151V TO TUBE POWER TRANSFORMER 203V -23.5V NEGATIVE 18 VOLT REGULATOR 155V 151V POSITIVE 18 VOLT REGULATOR
38、 156V 156V 0V 0V 18V 3A 3A 3A 3A J5:2 3A J5:3 3A J5:4 J5:5 J5:8 T125mAL250V F1 D22 D21 D19 47F C3 23.5V 2.21k R11 3 21 D S G Q3 132353 .1uF C104 -18V .1uF C103 221k R12 22.1 R15 220F C108 -18V 18V -18V 3A J5:1 3A J5:7 J5:6 D20 221k R9 3 21 Q2 #132351 31 2 Q1 #132317 SEC 3 J1:8 1M R10 J1:9 .047F C4 2
39、2.1k R14 200k R13 32 1 INOUT U18 220F C107 3 1 2 INOUT U17 J31:1 J31:7 J31:8 J31:2 J31:6 J31:4 J31:5 J31:3 157V 157V none R1 100V 20V 100V 20V From Backup Power Supply PCB ! 0 R2 MH1 J6:2 J6:6 J6:3 J6:4 J6:1 J6:7 18V 8V_UNREG 8V_UNREG 18V J7:3 J7:7 J7:1 J7:6 J7:4 J7:2 -18V -18V AC WINDING J7:5 J6:5
40、3 3 3 3 3 3 3 3 3 3 3 3 3 3 159405 (100-240V) ! 159406 (120V Only) T1 T1 1 1 T1 1 T1 1 1 BLK RED RED .047uF C17 D3 D4 T1 BLU .047uF C25 D7 1.85A t R195 1.85A t R19 D5 D2 D6 3.0A t R29 4700F C11 4700F C18 J1:2 J1:3 J1:1 SEC 1 10 9 8 7 12 SEC 2 1 3.0A t R35 J1:6 J1:5 J1:4 8V_UNREG YEL 10000F C24 11 YE
41、L 1 AC WINDING 200V Nominal D1 ZE 12V400MW 221k R3 .22F C1 15mA J1:7 NC FH1 499 R6 6.49k .5% R7 475 R8 6.49k .5% R5 18V -18V -18V 18V 18V 4.99k R4 18.8V 116V 10F C6 .047F C7 2.21k R16 220F C8 18.2V TP1 RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 6162 8 POWER 751459 PCB RadioFans.CN 收音机爱 好者资料库 63
42、64 9 TUBE 751461 SCH 1 of 3 1.2V 0V LEFT 2B 2B 2B J2:10 J2:11 J2:12 TO MAIN 2BJ2:9 TO AUDIO PCB 475k R6 475k R5 .047F C6 .047F C5 GND GND 1.2V 0V PHONO AMP 0V 105V PHONO AMP R MM OUT GND J4:2 J4:1 2B 2B J3:1 J3:22B 2B 953 R3 86V 47pF C2 RIGHT 953 R1 86V 47pF C1 .001uF C9 75kR8 1V 2.21M R10 12AX7A 8
43、6 7 V2:2 .001uF C8 75kR7 1V 2.21M R9 4.75k R12 12AX7A 8 6 7 V1:2 10F C7 2.21k R19 105V 33.2k R22 2.21k R18 33.2k R20 DS6 4.75k R75 4.75k R76 MM-OUT-GND GND L MM OUT 6.49k .5% R4 6.49k .5 % R2 4.75k R13 267k R16 47.5kR11 267k R14 21 3 Q2 21 3 Q1 #132352 DS5 31 2 Q8 DS3 R MM IN L MM IN 10 R77 12AX7A 5
44、 9 4 V1:3 12AX7A 5 9 4 V2:3 J2:2 J2:1 12AX7A 3 2 1 V2:1 J1:1 J1:2 12AX7A 3 2 1 V1:1 .0033F C11 1MR17 100F C13 1F C15 .0033F C10 1MR15 1F C14 J4:1 J4:5 J4:3 J4:7 TUBE_LED 157V 157V 157V 157V 18V18V 145V 145V 145V157V 18V 10pF C55 10pF C56 100F C12 10k R80 10k R21 12AX7A 5 9 4 V3:3 -18V Pulled high on
45、 Audio PCB thru 10k pullup 156V 156V 0V 0V 18V 8 8 8 8 J5:7 8 J5:6 8 J5:5 J5:4 J5:1 -18V 18V -18V 8 J5:8 8 J5:2 J5:3 J5:1 J5:7 J5:8 J5:2 J5:6 J5:4 J5:5 J5:3 157V 18V -18V TO POWER SUPPLY 47.5kR26 Rename high voltage nets to closely match measurements 1k R87 1k R88 47F C3 47F C4 18V 18V DS4 DS2 DS1 (
46、SHEILD ONLY) RadioFans.CN 收音机爱 好者资料库 TUBE PREAMPLIFIER C2500 6566 9 TUBE 751461 SCH 2 of 3 0V RIGHT GND 2B 2B 2B 475k R34 .9V 475k R33 LEFT GND 2B TO MAIN .047F C23 .047F C24 RIGHT MC J2:24A GND 4AJ8:2 LEFT MC 4AJ8:3 0V RIGHT 0V 86V 86V 1M R44 .6V 105V 105V R MC OUT J2:6 J2:3 J2:8 47pF C20 47pF C19
47、.001uF C26 1.82k R31 .9V 2.21M R38 12AX7A 3 2 1 V4:1 .001uF C25 1.82k R29 2.21M R37 12AX7A 3 2 1 V3:1 .0033F C28 .6V 4.75k R40 12AX7A 8 6 7 V4:2 267k R43 .0033F C27 1M R42 4.75k R39 12AX7A 8 6 7 V3:2 267k R41 1F C32 33.2k R49 1F C31 33.2k R47 J2:4 TO MAIN L MC OUT 6.49k .5 % R32 6.49k .5 % R30 75k R36 PHONO AMP PHONO AMP J4:8 PHONO AMP 75k R35 J4:6 J4:12 21 3 Q3 #132352 21 3 Q4 #132352 J4:10 157V 157V 145V 145V157V 157V MC-OUT-GND 10k R48 10k R50 J7:1 J7:2 J7