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SERVICE MANUAL
MIXING AMPLIFIER
MFEiE KL
()ProNEeR.
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.DISASSEMBLY.. ....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 ......23
11.4 SwitchCircuit-AAssembly ......33
12. PACKING METHOD AND PART NUMBERS ......36
,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/ L& R / R
CH3, CH4 (PAN-POT): L - R (Panoramic Potentiometer)
I nput (Sensitivity/l mpedance) :
MIC: 0.25mV l4.lkS]"
PHONO: 2.5mV / 50kS)
LINE: 50mV i 50kfi
MIC Attenuator: 0dB, -20d8
MIC Overload Level: 250mV rms (at attenuator -20d8)
PHONO Overload Level: 250mV rms (at ikHz)
Output: Stereox 2 (parallel)
Rated Output Level: 330mV
Harmonic Distortion Less than 0.2o/o (at 1V output)
Maximum Output: 5V (T.H.D.= 0.5%,50k0 load)
Channel Separation: More than 70dB (at l kHz)
Cross-talk: More than 70dB (at l kHz)
Frequency Response:
Mlc: 2}Hzto 15kHz (19d8)
PHONO: R IAA Equalization: t0.5dB
LINE: 2OHzto2SkHz(1?Oe)
MIC Low Cut: fc- 2OOHz (6dB/oct.)
Channel lnterference: Less than 1dB
Residual Hum & Noise: Less than 0.05mV
S/N (lHF, Short-Circuited, A Network)
MIC: 52dB
PHONO: 60dB
LINE: 67dB
Headphone Output: Maximum 260mV (8Sl)
MISCELLANEOUS
Power Requirements: AC 120V, 60Hz
PowerConsumption: 5W
Dimensions: 400tW) x 132(H) x 264(D) mm (15-3/4 x 5-3/16 x 10 3/8 in.)
Weight: Without Package: 5.8k9, 13 lb
With Package 7.3kq, 16 lb
FURNISHED PARTS
Connection Cordwith Pin Plus . . . . . . . 1
Operatinglnstructions ....... 1
NOTE: Specifications and the design subject to posslble modification without notice due to improvements.
MA.EiE
2. CONNECTION DIAGRAM
rrr
SPEAKER SYSTEN4S
STEREO TAPE DECK STEREO TAPE DECK
LEFT CHANNEL RIGHT CHANNFI (for recording) (for playback)
'o'
I
;tFF;:':l
C oO Oo O. C
e. Oec c OccO STER EO TURNTABLE
INPUT TERMINALS (AUX)
,e-iai
@ 0 ee e
Q r"o*.,
:l i;
F USE
120V mociei
T--- i:
ri
""t i
lr
t_:
1A
I
5-Line Voltage model
0.5A 220v
AC cord i
1A
240V
1
1
1
10V
20v
30v
L-ry4\tr"-i
iit i
ft HF
TT
.ii:{
] GROUND
@ t:;:;:;
MICROPHONES
STEREO HEADPHONES ":'U:t"
(for monitor)
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 This'set of terminals is for connecting a stereo turntable.
a power amplifier, or from tape decks, are connected to You should use a moving magnet type phono cartridge.
these inputs.
MICROPHONE I NPUT TERMI NALS
OUTPUT TERMTNALS ('.t, 2) Microphones should be connected to these iacks.
!fn.r. outputs are for connecting to the inputs of a tape The MA-62 functions superbly whether you use low or
or the auxiliary terminals of an amplifier. high impedance microphones.
ldeck
I
There are two kinds of OUTPUT 2 terminals; the 5-pin The upper iacks are used to connect 5-pin DIN-type plugs
iOtN type connector may be connected to a DIN plug of and the lower to connect usual phone type plugs. When in
rape deck for recording. simultaneous connections to both terminal sets only the
i
lAt the same time, the input terminals of pre-amplifier may phone type jacks are operative.
I be connectecJ to phono type terminals.
I
I
l
l
I
PHONES f ACK - - GROUND TERMINAL
This jack is for stereo headphone connection. The lf the turntable used has a ground wire, it should be
monitor function of the headphone will enable you to set connected to this terminal.
a good balance between the input sources distributed to
both stereo output channels.
NOTE:
l|e recommend the use of tightly fitting headphones such as
Pioneer model SE-305 effective in sealing out the outside sound.
MA-EiE!
6. CIRCUIT DESCRIPTION
Signal Path
1. T'he signals from the microphone terminals 6. The output terminals have both phono jacks
and the phono terminals (of channels 1 and and a DIN type connector. The two pairs
2 only) are amplified by the two NPN of phono jacks and DIN type connector are
transistors in the direct coupled NFB-type wired in parallel, so they can be used simul-
amplifier after selection with the input taneously, if necessary.
switches. 7. The headphone output signal (for monitor-
2. Both the standard jacks and the DIN type ing purposes) is a portion of the output
connectors can be used for the microphone which appears at the output terminals, am-
inputs, but as the standard jacks defeat the plified by an integrated circuit.
DIN connector, it is not possible to use the
standard jacks when a microphone is con-
nected to the DIN type connector for the The Microphone and Equalizer Amplifier
same channel. Stage
If two microphones are plugged into the Figure 1 is a simplified circuit diagram of the
same channel at the same time, only the one
plugged into the standard jack can be used. microphone/equalizer amplifier for channels 1
3. The amplified signals from the microphone and 2. The switching between the equalizer
function and the mike amp function is effected
or turntable are next fed to the resistors in by the switch marked S.
the mixing stage through the slider type level
The microphone input terminal has a sensitivity
controls of each channel (except 3 and 4,
which have pan-pots) and the output chan- of 0.25 mV while the phono input sensitivity is
2.5 mV at lkHz in each case, so altering the
nel selector switch.
gain by merely switching the CR element of the
4. The signals mixed by the resistors in the
closed loop NFB would cause instability, which
mixing stage are then amplified in the direct
would lead to distortion and noise.
coupled amplifier, by the PNP and the NPN
transistors (2 transistors in all).
Therefore, the amount of the current NFB
5. The signal taken from the NPN transistor from first stage transistor Q1 is changed by Sa,
emitter (emitter follower) passes through the and the CR element is switched, to determine
MASTER VOLUME potentiometer to be the frequency characteristics, by Sb.
amplified in another two-transistor direct
coupled amplifier and then sent to the
output terminals from the emitter follower.
OUTPUT
INPUT
PHONO-MlC PH0NO*MlC Fig. 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
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 RM's, changes in the signal levels from
each source may occur due to the different
output impedances of the sources connected to
A thru F. To prevent this, resistances of 33OkSl
are used as RM's 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 values.
To fulfill this condition, parallel feed-type NFB
is applied from the emitter of Qq to the base of
Q: in the mixing ampli{ier. 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.
)
O
cc
o
cr F
(J
F
z
o
uJ
J
C) LU
J
a MIXING CIRCUIT (L CHANNEL)
Lri F
f RNF
ui o-
I L
F
l
o
L&R RM,
RM,
OUTPUT
RMe
RM, -RM6: ISOLATION RESISTORS (330k,f2)
RNF: NFB RESISTOR (560ks-,)
To Mixing Circuit
(R Channel) Fig.2
10
MA.EiE
7. LEVEL DIAGRAM
EOUA tI ZERl
MIC AMP
OUTPUT
LINE HEADPHONES
Mrc
I
j, I
cb
E
$
.:-
L
HIADPHON E5
m -30
-O
l4qnvl
Z
__l
(o
N
!! -an I
L!
J
l CD
c
(o
'f- I
l
I
FREQUENCY AT 1kHz. 0dBV- 1V
11
8. DISASSE M BLY
Removal of Side Panels (See Exploded Removing the Front Panel
View.)
3. First, take off all the control knobs and
1. To remove the left and right side panels take slider caps, taking care not to lose the
out the three securing screws as illustrated, springs from inside the individual level con-
being careful not to lose the washers. trols and the master volume control.
4. Next, remove the two fixing screws at the
Removing the Bottom Cover front of the front panel, and the four at the
back. Do not forget to take off the rubber
2. After the side panels have been removed, feet at the back of the panel, as these two
there are only two screws to take out before are attached with screws also.
the bottom cover can be detached. Please
refer to the exploded view below.
$
(;
"b., Fis. 3
T2
MA.CiE
The Microphone Amplifier Assembly The Switch Assembly (B)
5. This assembly is removed by taking out the 7. Switch B ass'y may be removed once the
six fixing screws as shown in the diagram four fixing screws have been taken out.
(Figure 4).
The Volume Controls
The Switch Assembly (A)
8. The two-ganged volume controls and the
6. After the mike amp ass'y has been removed, slider volume controls may be removed in-
the switch assembly (A) may be taken off. dividually, after the microphone amplifier
Again, the six fixing screws must be removed assembly has been taken off, by unscrewing
first. the securing nuts and setscrews in each case.
SWITCH CIRCUIT-
ASSEMBLY
AWS-061-O
'ru -l
I
SWITCH CIRCUIT-A
ASSEMB LY
AWS-060-0
MICROPHONE AMPLIFIER
ASSEMBLY
AWM-056-0
Fis.4
13
9. PARTS AND P.C. BOARD LOCATION
Top View
VARIABLE RESISTOR
(LEVEL)
ACX-003-0
ROUND SHADING
PLATE (A}
AEC-132-0
ROUND SHADING
PLATE (A) ROUND SHADING
AEC-132-0 PLATE (B)
AEC.133-A
SHADING PLATE (A)
AED-021-0
VARIABLE RESISTOR
(PAN.POT)
ACV-128-O PHONO JACK B (6 JACKS)
AKB-017-0
HANDLE
ANH.179-A
PHONO JACK-A (4 JACKS)
AKB-014-0
ROUND SHADING
PLATE (A)
AEC-132-0
FUSE HOI-DER
AKR-020-0
PILOT LAMP BV, 50mA
VARIABLE RESISTOR A E L-007-0
(MASTER)
ACX-106-0 PUSH SWITCH (POWER)
A SG-023-0
AC POWER CORD
SHADING PLATE (B) ADG-O05-O
AED-022-0
t4
MA-6E!
Bottom View
PO\AJER TRANSFORMER
ATT-203-0
AC SOCKET
AKP-002-0
PHONE JACK
SWITCH CI RCU IT.B ASSEMB LY (HEADPHONES)
AWS-061-0 K72-026-0
SWITCH
CIRCUIT.A
ASSEMBLY
AWS-060-0
MIC AMPLIFIER ASSEMBLY BINDING POST
AWM-056-A FOR GROUND
AKE-0i 7-0
PHONE JACK
SWITCH CIRCUIT.B ASSEMB LY (MICROPHONE)
AWS-061-0
K72-O24-O
15
10. EXPLODED VIEW AND PARTS LIST
NOTE: Any parts asterisked(* ) are sLrb ject to tleinq not supplierl
Key No. Description Part No
1 Knob (LEVEL, MASTER) RAA 095.0
2 Spr i ng RBK 042 B
3 Knob (memory marker) R N K,042 A
4 Front panel assembly AN B-234 A
5 Knob {PAN'POT) AAB-072 0
Knob supporter AEC.136.4
l Bottom cover ANE-041 A
B Foot AEC 135.A
9 Screur M4 x 26 ABA,O1 1 A
10 Side board iL) AMS OO5,A
11 Handle stay assembly (L) ANG 094 A
12 Switch circuit B assembly AWS O6i O
13 Switch circuit-B assembly AWS 061-0
14 Handle ANH,179 A
15 l\1ic amplif ier assembly AWM 056 A
16 Handle stay assembly (R) ANG 094 O
1l Round shading plate (B) AE C 33.A
1
t6 Rou nd shading plate (A) AEC 132 O
19 Shading plate (A) AED-021 0
20 Shadlng plate (B) AED O22-O
21" Chassis AN A-059 C
22' Shield plate ANH 181-0
Variable resistor 25OkJ)'AC (PAN-POT) ACV-128 0
24 Phone jack iMICROPHON E) K72 024.0
25 Insulator (washer) E32-045-A
lb Phono jack'B (6 lacks) AKB 017-0
27 Phono jack A (4 jacks) AKB 014,0
Variable resisror 100kI),A2 (LEVE L) ACX,003-0
29 Variable resistor'1 00k{l'A2 (MASTER ) ACX 106-0
30 Phone jack (HEADPHONES) Kl2 026.0
31 Nut (insulator) 871 031-0
32 Washer (insulator) E34 014-0
Rubber gromnet AEB.O34-A
34 Pilot lamp BV, 5OmA AEL OO7 O
35 Binding post for ground AKE 017-0
36 Ground terrrinal strip (4P) K 13-047-0
31 Fuse holder (AC power) AK R-020 0
JO AC socket AKP 002,0
39 AC socket-held metal l\n49 121,A
40 AC power cord ADG OO5 O
41 AC cord grommet AEC 079-0
42 Side boarcl (R ) AMS 006 A
43 Knob (PO''\tER) AAD,045 0
44 Push switch (POWER ) ASG 023-0
45'. P.C. board lrolder AN F-177 0
46 Switch circu it'A asse{nblV AWS 060,0
41 Pon,er transfonrer ATT-203 0
48 Connector {DlN tVpe 5P) K93 003 B
16
MA.EiE
RESISTORS
Symbol Description Part No.
R1 Carbon film ik R D'l.PS 1 O2J
R2 Carbon f ilm 1k RD%PS 1O2J
R3 Carbon film 91k RD74PS 9'1 3J
R4 Carbon film 91 k RD%PS 913J
R5 Carbon f ilm 180k RD%PS 184J
R6 Carbon f ilm 180k RD%PS 184J
R7 Carbon film 3k RD%PS 302J
R8 Carbon film 3k RD%PS 3O2J
R9 Carbon f ilm 120k RD74PS 124J
R10 Carbon film 12Ok RD%PS 124J
R11 Carbon film 6B0k RD%PS 684J
R12 Carbon film 680k RD%PS 684J
R13 Carbon film 47k RD%PS 473J
R14 Carbon film 41k R D7.PS 473J
R15 Carbon film 22Ok RD%PS 224J
R16 Carbon film 22Ok RD%PS 224J
R17 Carbon f ilm 1.5k '1
R D% PS 52J
R18 Carbon f ilm 1.5k RD%PS 152J
R19 Carbon film 39k RD7"PS 393J
R20 Carbon film 39k RD%PS 393J
R21 Carbon film 300k RD7.PS 3O4J
R22 Carbon film 3O0k RD%PS 3O4J
R23 Carbon film 4.3k RfJ%PS 432J
R24 Carbon film 4.3k RD7.PS 432J
R25 Carbon film lBk RD%PS,183J
fi 2t) Carbon film lBk RD%PS 183J
R2l Carbon f ilm 1k RD%PS 1O2J
R28 Carbon f ilm 1k RD7.PS 1O2J
R29 Carbon film 68k RD%PS 683J
R30 Carbon f ilm 68k R DIAPS 683J
R31 Carbon film 2.2k RD./"PS 222J
o1a Carbon film 2.2k RD%PS 222J
R33 Carbon f ilm 1k RD%PS 1O2J
R34 Carbon f ilm 1k RD%PS 1O2J
D2t Carbon f ilm 9'1 k RD74PS 913J
R36 Carbon f ilm 91k RD%PS 91 3J
R37 Carbon film 180k RD%PS 184J
R38 Carbon film 180k RD%PS 184J
R39 Carbon f ilm 1k RD74PS 1O2J
R40 Carbon f ilm 1k RD74PS iO2J
R41 Carbon {ilm 12Ok RD%PS 124J
R42 Carbon f ilm 120k RD%PS 124J
R43 Carbon film 22Ok RDY^PS 224J
R44 Carbon film 22Ok RD%PS 224J
R45 Carbon film 3O0k RD7.PS 3O4J
R46 Carbon film 30Ok RD74PS 3O4J
R4l Carbon film 2.lk RDY"PS 272J
R48 Carbon film 2.1k RD%PS 212J
R49 Carbon film 18k RD%PS 183J
R50 Carbon f ilm '18k RD%PS 183J
ConlinLred on ltre Nexl Pdqe 29
MICROPHONE AMPLI FIER ASSEMBLY
Symbol Description Part No.
R51 Carbon film 68k RD%PS 683J
H5l Carbon film 68k RD%PS 683J
R53 Carbon film 22k RD%PS 222J
R54 Carbon film 2.2k RD%PS 222J
R55 Carbon film 1k R Dil4PS 1O2J
R56 Carbon f ilm 1k RD%PS 1O2J
R57 Carbon f ilm 91k RD%PS 913J
R58 Carbon f ilm 91k RD%PS 913J
R59 Carbon film 1BOk RD%PS 1B4J
R60 Carbon f ilm 180k RD%PS 184J
R61 Carbon f ilm 1k RD%PS 1O2J
R62 Carbon f ilm 1k RD%PS 1O2J
R63 Carbon f ilm 120k RD%PS 124J
R64 Carbon f ilm '1
20k RD%PS 124J
R65 Carbon film 22Ok RD%PS 224J
R66 Carbon film 22Ok RD%PS 224J
R67 Carbon film 300k RD%PS 3O4J
R68 Carbon film 300k RD%PS 3O4J
R69 Carbon f ilm 2.lk RD%PS 2]2J
R70 Carbon film 2.lk RD%PS 2]2J
R71 Carbon film 18k RD%PS 183J
R72 Carbon film 18k RD%PS 183J
R73 Carbon film 68k RD%PS 683J
Rl4 Carbon film 68k RD%PS 6B3J
R75 Carbon film 2.2k RD%PS 222J
R76 Carbon film 2.2k RD%PS 222J
R77 Carbon f ilm 33Ok RD%PS 334J
R78 Carbon film 330k RD%PS 334J
R79 Carbon film 330k RD%PS 334J
R80 Carbon film 330k R D74PS 334J
R81 Carbon film 330k RD%PS 334J
R82 Carbon f ilm 330k RD%PS 334J
R83 Carbon {ilm 330k RD%PS 334J
R84 Carbon film 330k RD%PS 334J
R85 Carbon film 330k RD%PS 334J
R86 Carbon film 330k RD%PS 334J
R87 Carbon film 330k RD74PS 334J
R88 Carbon film 330k RD%PS 334J
R89 Carbon film 2.2k RD%PS 222J
R90 Carbon film 2.2k RD%PS 222J
R91 Carbon film 2.2M RD%PS 225J
R92 Carbon film 2.2M RD%PS 225J
R93 Carbon film 1.2M R D%PS
,1
25J
R94 Carbon f ilm 1.2M RD%PS 125J
R95 Carbon film 360k RD%PS 364J
R96 Carbon f ilm 360k RD%PS 364J
R97 Carbon f ilm 1.5k RD%PS 152J
R98 Carbon f ilm I.5k RD%PS 152J
R99 Carbon f ilm 62k RD%PS 623J
R 100 Carbon film 62k RD%PS 623J
30
MICROPHONE AMPLI FI ER ASSEMBLY
MA-EiE
Parts List of Switch Circuit-A Assembly (AWS-060-0)
CAPACITORS
Symbol Description Part No.
C1 Mylar 0.018 50V COIVIAl 83K 50
C2 Mylar 0.018 50V COMA183K 50
C3 Mylar 0.018 50V COMAl83K 50
C4 Mylar 0,018 50V COMA183K 50
C5 Mylar 0.018 50V COMA183K 50
C6 Mylar 0.018 50V coMA183K 50
RESISTORS
Symbol Description Part No.
R1 Carbon film 4lO RD%PS 471J
R2 Carbon film 4.lk RD%PS 412J
R3 Carbon film 47O RD%PS 47iJ
R4 Carbon film 4.1k RD%PS 472J
R5 Carbon film 4'7O RD%PS 471J
R6 Carbon film 4.1k RD%PS 4]2J
R7 Carbon film 4lO RD%PS 471J
nd Carbon film 4.lk RD%PS 412J
R9 Carbon film 41O RD%PS 471J
R'1 0 Carbon film 4.1k RD%PS 412J
R'1 1 Carbon film 47O RD%PS 471J
R12 Carbon film 4.1k RD%PS 4]2J
SWITCHES
Symbol Description Part No.
S1 Slide switch (INPUT) ASH-010-0
et Slide switch (INPUT) ASH-010,0
S3 Slide switch (INPUT) ASH-009-0
S4 Slide switch (INPUT) ASH-009,0
CA Slide switch (INPUT) ASH-009-0
S6 Slide switch (INPUT) ASH-009-0
S7 Slide switch (MlC LOW-CUT) ASH,009-0
S8 Slide switch iMlC LOW-CUT) ASH-009-0
S9 Slide switch iMlC LOW-CUT) ASH,009,0
s10 Slide switch (MlC LOW-CUT) ASH-009-0
s1 1 Slide switch (MlC LOW-CUT) ASH-009-0
s12 Slide switch (MlC LOW-CUTi ASH-009-0
s13 Slide switch (MlC ATTENUATOR) ASH-009-0
s14 Slide switch (MlC ATTENUATOR) ASH-009-0
s15 Slide switch (MlC ATIENUATOR) ASH-009-0
s16 Slide switch (MlC ATTENUATOR) ASH-009,0
s17 Slide switch (MlC ATTENUATOR) ASH-009-0
s18 Slide switch {MlC ATTENUATOR) ASH-009-0
35
12. PACKING METHOD AND PART NUMBERS
CAR DBOA RD
AHB-015-0
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)
PACKING CASE
AHD-2i 0-0
Jr)
PIONEEFI ELECTFI(fNIC COFII'OFIATION
, I Cirome, Meguno, Meguno,ku, Tokyo 1 53, Japa.
:1- 1
U.S. FIONEEF| ELECTFIONICA COFIPC'F|ATEN
75 Oxfo.d Dtrrve, Moonach e, New Jensey O7O7.4,U.S.A.
PIONEEFI ELECTFIONIC (EUFIOPEI N.V.
Mern-Cencen Mern 2-T, 2OOO A-twenp. Betgrum
PIONEEFI ELECTFIONICEi AIJSTFIALIA PTY. LTEI.
256-A C tV trload South Me bou.ne. V ctonra 3205. Arrsrna a
o sEP. 1974 Printed in Japan