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1、 SERVICE MANUAL MIXING AMPLIFIER MFEiE KL ()ProNEeR. RadioFans.CN 收音机爱 好者资料库 MA-CiE! CONTENTS I.SPEC|F|CAT|ONS .2 2. CONNECTION DIAGRAM . . . . 3 3. NAMES OF CONNECTORS ON THE BACK PANEL ., 4 4.FRONTPANELFACILITIES .5 5. BLOCK DIAGRAM . 7 6.C|RCU|TDESCRTPTTON. .9 7. LEVEL DIAGRAM . . . . . .11 S.DIS
2、ASSEMBLY. .12 9. PARTS AND P.C. BOARD LOCATION . . . .14 10. EXPLODED VIEW AND PARTS LIST . . . . .16 11. SCHEMATIC DIAGRAMS, P.C. BOARD PATTERNS AND PARTS LISTT 11.1 Circuit Connection Diagram and Miscellaneous Parts . . .19 11.2 Switch Circuit-B Assembly . . . .22 11.3 MicrophoneAmplifierAssembly
3、.23 11.4 SwitchCircuit-AAssembly .33 12. PACKING METHOD AND PART NUMBERS .36 RadioFans.CN 收音机爱 好者资料库 ,1. SPECIFICATIONS SEMICONDUCTORS lCs. .2 Transistors .22 Diodes .3 lnput Select: CH1, CH2: MIC i PHONO CH3, CH4, CH5, CH6: MIC / LINE Output Channel Select: CH1,CH2, CH5,CH6: L/ LtFF;:l ,e-iai Q ro*
4、., SPEAKER SYSTEN4S LEFT CHANNEL RIGHT CHANNFI rrr STEREO TAPE DECK (for recording) STEREO TAPE DECK (for playback) STER EO TURNTABLE INPUT TERMINALS (AUX) F USE 120V mociei 1A eee lr t_: T- 0 :l i: ri i t I i; AC 5-Line Voltage model 0.5A 220v 240V 1A 1 10V 1 20v 1 30v i L-ry4tr-i MICROPHONES cord
5、i iit ft GROUND TT HF .ii: t:;:;:; :U:tSTEREO HEADPHONES (for monitor) C oO Oo O. C e. Oec c OccO 3. NAMES OF CONNECTORS ON THE BACK PANEL LINE TNPUT TERMTNALS (CH 3, 4,5,6)HONO TNPUT TERMTNALS (CH 1,CH 2) Outputs from stereo tuners, from the recording output of a power amplifier, or from tape decks
6、, are connected to these inputs. OUTPUT TERMTNALS (.t, 2) !fn.r. outputs are for connecting to the inputs of a tape ldeck or the auxiliary terminals of an amplifier. I There are two kinds of OUTPUT 2 terminals; the 5-pin iOtN type connector may be connected to a DIN plug of i rape deck for recording
7、. lAt the same time, the input terminals of pre-amplifier may I be connectecJ to phono type terminals. I I l l PHONES f ACK This jack is for stereo headphone connection. The monitor function of the headphone will enable you to set a good balance between the input sources distributed to both stereo o
8、utput channels. NOTE: l|e recommend the use of tightly fitting headphones such as Pioneer model SE-305 effective in sealing out the outside sound. Thisset of terminals is for connecting a stereo turntable. You should use a moving magnet type phono cartridge. MICROPHONE I NPUT TERMI NALS Microphones
9、should be connected to these iacks. The MA-62 functions superbly whether you use low or high impedance microphones. The upper iacks are used to connect 5-pin DIN-type plugs and the lower to connect usual phone type plugs. When in simultaneous connections to both terminal sets only the phone type jac
10、ks are operative. I - - GROUND TERMINAL lf the turntable used has a ground wire, connected to this terminal. it should be 6. CIRCUIT DESCRIPTION Signal Path 1. The signals from the microphone terminals and the phono terminals (of channels 1 and 2 only) are amplified by the two NPN transistors in the
11、 direct coupled NFB-type amplifier after selection with the input switches. 2. Both the standard jacks and the DIN type connectors can be used for the microphone inputs, but as the standard jacks defeat the DIN connector, it is not possible to use the standard jacks when a microphone is con- nected
12、to the DIN type connector for the same channel. If two microphones are plugged into the same channel at the same time, only the one plugged into the standard jack can be used. 3. The amplified signals from the microphone or turntable are next fed to the resistors in the mixing stage through the slid
13、er type level controls of each channel (except 3 and 4, which have pan-pots) and the output chan- nel selector switch. 4. The signals mixed by the resistors in the mixing stage are then amplified in the direct coupled amplifier, by the PNP and the NPN transistors (2 transistors in all). 5. The signa
14、l taken from the NPN transistor emitter (emitter follower) passes through the MASTER VOLUME potentiometer to be amplified in another two-transistor direct coupled amplifier and then sent to the output terminals from the emitter follower. INPUT MA-EiE! 6. The output terminals have both phono jacks an
15、d a DIN type connector. The two pairs of phono jacks and DIN type connector are wired in parallel, so they can be used simul- taneously, if necessary. 7. The headphone output signal (for monitor- ing purposes) is a portion of the output which appears at the output terminals, am- plified by an integr
16、ated circuit. The Microphone and Equalizer Amplifier Stage Figure 1 is a simplified circuit diagram of the microphone/equalizer amplifier for channels 1 and 2. The switching between the equalizer function and the mike amp function is effected by the switch marked S. The microphone input terminal has
17、 a sensitivity of 0.25 mV while the phono input sensitivity is 2.5 mV at lkHz in each case, so altering the gain by merely switching the CR element of the closed loop NFB would cause instability, which would lead to distortion and noise. Therefore, the amount of the current NFB from first stage tran
18、sistor Q1 is changed by Sa, and the CR element is switched, to determine the frequency characteristics, by Sb. OUTPUT PHONO-MlC PH0NO*MlCFig. 1 Mixing Stage The mixing circuit of this unit is a very ortho- dox and highly stable series resistance circuit using isolation resistors. Resistors RMr thru
19、RM6 in the diagram are such isolation resistors. The signals to be mixed are fed to terminals A thru F, and perfect mixing is obtained at point X in the diagram. If low resistance values are used as RMs, changes in the signal levels from each source may occur due to the different output impedances o
20、f the sources connected to A thru F. To prevent this, resistances of 33OkSl are used as RMs in this unit-differences due to output impedance are negligible. To prevent interference between the various signals, the impedance at point X (the mixing point) must be kept quite low in relation to the RM v
21、alues. To fulfill this condition, parallel feed-type NFB is applied from the emitter of Qq to the base of Q: in the mixing ampliier. This not only helps to reduce distortion and noise (the effect of NFB), but also keeps the input impedance of Q3 verj low, maintaining stable operation. cc o F (J uJ J
22、 LU a F f o- F l o L ) O cr F z o C) J Lri ui I MIXING CIRCUIT (L CHANNEL) RNF OUTPUT RM, -RM6: ISOLATION RESISTORS (330k,f2) RNF: NFB RESISTOR (560ks-,) L T2 b., Fis. 3 I -l ru 6. After the mike amp the switch assembly Again, the six fixing first. assy has been removed, (A) may be taken off. screws
23、 must be removed The Microphone Amplifier Assembly 5. This assembly is removed by taking out the six fixing screws as shown in the diagram (Figure 4). The Switch Assembly (A) MA.CiE The Switch Assembly (B) 7. Switch B assy may be removed once the four fixing screws have been taken out. The Volume Co
24、ntrols 8. The two-ganged volume controls and the slider volume controls may be removed in- dividually, after the microphone amplifier assembly has been taken off, by unscrewing the securing nuts and setscrews in each case. SWITCH CIRCUIT-A ASSEMB LY AWS-060-0 SWITCH CIRCUIT- ASSEMBLY AWS-061-O MICRO
25、PHONE AMPLIFIER ASSEMBLY AWM-056-0 13 Fis.4 9. PARTS AND Top View VARIABLE RESISTOR (LEVEL) ACX-003-0 ROUND SHADING PLATE (A) AEC-132-0 VARIABLE RESISTOR (PAN.POT) ACV-128-O HANDLE ANH.179-A ROUND SHADING PLATE (A) AEC-132-0 VARIABLE RESISTOR (MASTER) ACX-106-0 SHADING PLATE (B) AED-022-0 P.C. BOARD
26、 LOCATION ROUND SHADING PLATE (A AEC-132-0 ROUND SHADING PLATE (B) AEC.133-A SHADING PLATE AED-021-0 PHONO JACK AKB-017-0 B (6 JACKS) PHONO JACK-A (4 JACKS) AKB-014-0 FUSE HOI-DER AKR-020-0 PILOT LAMP BV, 50mA A E L-007-0 PUSH SWITCH (POWER) A SG-023-0 AC POWER ADG-O05-O CORD (A) t4 Bottom View SWIT
27、CH CI RCU IT.B ASSEMB LY AWS-061-0 MIC AMPLIFIER ASSEMBLY AWM-056-A SWITCH CIRCUIT.B ASSEMB LY AWS-061-0 MA-6E! POAJER TRANSFORMER ATT-203-0 AC SOCKET AKP-002-0 PHONE JACK (HEADPHONES) K72-026-0 SWITCH CIRCUIT.A ASSEMBLY AWS-060-0 BINDING POST FOR GROUND AKE-0i 7-0 PHONE JACK (MICROPHONE) K72-O24-O
28、15 10. EXPLODED VIEW AND PARTS LIST NOTE: Any parts asterisked(* ) are sLrb ject to tleinq not supplierl Key No.Description Part No 1 2 3 4 5 Knob (LEVEL, MASTER) Spr i ng Knob (memory marker) Front panel assembly Knob PANPOT) RAA 095.0 RBK 042 B R N K,042 A AN B-234 A AAB-072 0 AEC.136.4 ANE-041 A
29、AEC 135.A ABA,O1 1 A AMS OO5,A l B 9 10 11 12 13 14 15 16 1l t6 19 20 21 22 24 25 lb 27 29 30 31 32 34 35 Knob supporter Bottom cover Foot Screur M4 x 26 Side board iL) Handle stay assembly (L) Switch circuit B assembly Switch circuit-B assembly Handle l1ic amplif ier assembly Handle stay assembly (
30、R) Round shading plate (B) Rou nd shading plate (A) Shading plate (A) Shadlng plate (B) Chassis Shield plate Variable resistor 25OkJ)AC (PAN-POT) Phone jack iMICROPHON E) Insulator (washer) ANG 094 A AWS O6i O AWS 061-0 ANH,179 A AWM 056 A ANG 094 O AE C 1 33.A AEC 132 O AED-021 0 AED O22-O AN A-059
31、 C ANH 181-0 ACV-128 0 K72 024.0 E32-045-A Phono jackB (6 lacks) Phono jack A (4 jacks) Variable resisror 100kI),A2 (LEVE L) Variable resistor1 00klA2 (MASTER ) Phone jack (HEADPHONES) Nut (insulator) Washer (insulator) Rubber gromnet Pilot lamp BV, 5OmA Binding post for ground AKB 017-0 AKB 014,0 A
32、CX,003-0 ACX 106-0 Kl2 026.0 871 031-0 E34 014-0 AEB.O34-A AEL OO7 O AKE 017-0 K 13-047-0 AK R-020 0 AKP 002,0 ln49 121,A ADG OO5 O AEC 079-0 AMS 006 A AAD,045 0 ASG 023-0 AN F-177 0 36 31 JO 39 40 41 42 43 44 45. Ground terrrinal strip (4P) Fuse holder (AC power) AC socket AC socket-held metal AC p
33、ower cord AC cord grommet Side boarcl (R ) Knob (POtER) Push switch (POWER ) P.C. board lrolder 46 41 48 Switch circu itA assenblV Pon,er transfonrer Connector DlN tVpe 5P) AWS 060,0 ATT-203 0 K93 003 B 16 RESISTORS SymbolDescription Part No. R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16 R1
34、7 R18 R19 R20 R21 R22 R23 R24 R25 fi 2t) R2l R28 R29 R30 R31 o1a R33 R34 D2t R36 R37 R38 R39 R40 R41 R42 R43 R44 R45 R46 R4l R48 R49 R50 Carbon film ik Carbon f ilm 1k Carbon film 91k Carbon film 91 k Carbon f ilm 180k Carbon f ilm 180k Carbon film 3k Carbon film 3k Carbon f ilm 120k Carbon film 12O
35、k Carbon film 6B0k Carbon film 680k Carbon film 47k Carbon film 41k Carbon film 22Ok Carbon film 22Ok Carbon f ilm 1.5k Carbon f ilm 1.5k Carbon film 39k Carbon film 39k Carbon film 300k Carbon film 3O0k Carbon film 4.3k Carbon film 4.3k Carbon film lBk Carbon film lBk Carbon f ilm 1k Carbon f ilm 1
36、k Carbon film 68k Carbon f ilm 68k Carbon film 2.2k Carbon film 2.2k Carbon f ilm 1k Carbon f ilm 1k Carbon f ilm 91 k Carbon f ilm 91k Carbon film 180k Carbon film 180k Carbon f ilm 1k Carbon f ilm 1k Carbon ilm 12Ok Carbon f ilm 120k Carbon film 22Ok Carbon film 22Ok Carbon film 3O0k Carbon film 3
37、0Ok Carbon film 2.lk Carbon film 2.1k Carbon film 18k Carbon f ilm 18k R Dl.PS 1 O2J RD%PS 1O2J RD74PS 91 3J RD%PS 913J RD%PS 184J RD%PS 184J RD%PS 302J RD%PS 3O2J RD74PS 124J RD%PS 124J RD%PS 684J RD%PS 684J RD%PS 473J R D7.PS 473J RD%PS 224J RD%PS 224J R D% PS 1 52J RD%PS 152J RD7PS 393J RD%PS 393
38、J RD7.PS 3O4J RD%PS 3O4J RfJ%PS 432J RD7.PS 432J RD%PS,183J RD%PS 183J RD%PS 1O2J RD7.PS 1O2J RD%PS 683J R DIAPS 683J RD./PS 222J RD%PS 222J RD%PS 1O2J RD%PS 1O2J RD74PS 913J RD%PS 91 3J RD%PS 184J RD%PS 184J RD74PS 1O2J RD74PS iO2J RD%PS 124J RD%PS 124J RDYPS 224J RD%PS 224J RD7.PS 3O4J RD74PS 3O4J
39、 RDYPS 272J RD%PS 212J RD%PS 183J RD%PS 183J MA.EiE MICROPHONE AMPLI FIER ASSEMBLY ConlinLred on ltre Nexl Pdqe 29 SymbolDescriptionPart No. R51 H5l R53 R54 R55 R56 R57 R58 R59 R60 R61 R62 R63 R64 R65 R66 R67 R68 R69 R70 R71 R72 R73 Rl4 R75 R76 R77 R78 R79 R80 R81 R82 R83 R84 R85 R86 R87 R88 R89 R90
40、 R91 R92 R93 R94 R95 R96 R97 R98 R99 R 100 Carbon film Carbon film Carbon film Carbon film Carbon film 68k 68k 22k 2.2k 1k Carbon f ilm 1k Carbon f ilm 91k Carbon f ilm 91k Carbon film 1BOk Carbon f ilm 180k Carbon f ilm 1k Carbon f ilm 1k Carbon f ilm 120k Carbon f ilm 1 20k Carbon film 22Ok Carbon
41、 film 22Ok Carbon film 300k Carbon film 300k Carbon f ilm 2.lk Carbon film 2.lk Carbon f ilm 18k Carbon f ilm 18k Carbon film 68k Carbon film 68k Carbon film 2.2k Carbon film 2.2k Carbon f ilm 33Ok Carbon film 330k Carbon film 330k Carbon film 330k Carbon film 330k Carbon f ilm 330k Carbon ilm 330k
42、Carbon film 330k Carbon film 330k Carbon film 330k Carbon film 330k Carbon film 330k Carbon film 2.2k Carbon film 2.2k Carbon film 2.2M Carbon film 2.2M Carbon film 1.2M Carbon f ilm 1.2M Carbon film 360k Carbon f ilm 360k Carbon f ilm 1.5k Carbon f ilm I.5k Carbon f ilm 62k Carbon film 62k RD%PS 68
43、3J RD%PS 683J RD%PS 222J RD%PS 222J R Dil4PS 1O2J RD%PS 1O2J RD%PS 913J RD%PS 913J RD%PS 1B4J RD%PS 184J RD%PS 1O2J RD%PS 1O2J RD%PS 124J RD%PS 124J RD%PS 224J RD%PS 224J RD%PS 3O4J RD%PS 3O4J RD%PS 22J RD%PS 22J RD%PS 183J RD%PS 183J RD%PS 683J RD%PS 6B3J RD%PS 222J RD%PS 222J RD%PS 334J RD%PS 334J
44、 RD%PS 334J R D74PS 334J RD%PS 334J RD%PS 334J RD%PS 334J RD%PS 334J RD%PS 334J RD%PS 334J RD74PS 334J RD%PS 334J RD%PS 222J RD%PS 222J RD%PS 225J RD%PS 225J R D%PS ,1 25J RD%PS 125J RD%PS 364J RD%PS 364J RD%PS 152J RD%PS 152J RD%PS 623J RD%PS 623J 30 MICROPHONE AMPLI FI ER ASSEMBLY MA-EiE Parts Lis
45、t of Switch Circuit-A Assembly (AWS-060-0) CAPACITORS SymbolDescriptionPart No. C1 C2 C3 C4 C5 C6 Mylar 0.018 50V Mylar 0.018 50V Mylar 0.018 50V Mylar 0,018 50V Mylar 0.018 50V Mylar 0.018 50V COIVIAl 83K 50 COMA183K 50 COMAl83K 50 COMA183K 50 COMA183K 50 coMA183K 50 RESISTORS SymbolDescriptionPart
46、 No. R1 R2 R3 R4 R5 R6 R7 nd R9 R1 0 R1 1 R12 Carbon film 4lO Carbon film 4.lk Carbon film 47O Carbon film 4.1k Carbon film 47O Carbon film 4.1k Carbon f ilm 4lO Carbon film 4.lk Carbon film 41O Carbon film 4.1k Carbon f ilm 47O Carbon film 4.1k RD%PS 471J RD%PS 412J RD%PS 47iJ RD%PS 472J RD%PS 471J
47、 RD%PS 42J RD%PS 471J RD%PS 412J RD%PS 471J RD%PS 412J RD%PS 471J RD%PS 42J SWITCHES SymbolDescriptionPart No. S1 et S3 S4 CA S6 S7 S8 S9 s10 s1 1 s12 s13 s14 s15 s16 s17 s18 Slide switch (INPUT) Slide switch (INPUT) Slide switch (INPUT) Slide switch (INPUT) Slide switch (INPUT) Slide switch (INPUT)
48、 Slide switch (MlC LOW-CUT) Slide switch iMlC LOW-CUT) Slide switch iMlC LOW-CUT) Slide switch (MlC LOW-CUT) Slide switch (MlC LOW-CUT) Slide switch (MlC LOW-CUTi Slide switch (MlC ATTENUATOR) Slide switch (MlC ATTENUATOR) Slide switch (MlC ATIENUATOR) Slide switch (MlC ATTENUATOR) Slide switch (MlC
49、 ATTENUATOR) Slide switch MlC ATTENUATOR) ASH-010-0 ASH-010,0 ASH-009-0 ASH-009,0 ASH-009-0 ASH-009-0 ASH,009-0 ASH-009-0 ASH,009,0 ASH-009-0 ASH-009-0 ASH-009-0 ASH-009-0 ASH-009-0 ASH-009-0 ASH-009,0 ASH-009-0 ASH-009-0 35 12. PACKING METHOD AND PART NUMBERS SIDE PAD (L) AHA-044-0 VINYL COVER AHG 016-0 SIDE PAD (R) AHA,045,0 CLOTH BAG AHG-017-0 (Cover MA-62) CAR DBOA RD AHB-015-0 PACKING CASE AHD-2i 0-0 Jr) PIONEEFI ELECTFI(fNIC COFIIOFIATION :1- 1 , I Cirome, Meguno, Meguno,ku, Tokyo 1 53, Japa. U.