Akai PR-A06 User manual

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90V-dd
STEREO PRE-AMPLIFIER
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PR-AQ6
DC
STEREO
POWER
AMPLIFIER
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PA=WO6

TABLE OF CONTENTS
SECTION 1 MODEL PR-AO6........
SECTION 2 MODEL PA-W06........
SECTION 3 PARTS LIST...........
SECTION 4 SCHEMATIC DIAGRAM .
PR-AO6
PA-WO06

SECTION 1
STEREO PRE-AMPLIFIER
MODEL PR-A06
ALSO APPLICABLE TO BLACK PANEL MODEL
TABLE OF CONTENTS
I = TECHNICAL DATA... 1. oe cee ee eet tenes 4
Il. DISMANTLING OF UNIT ..... 0... 0. ccc eee eee eee 5
I. CONTROLS ............. pad seca Cater alone eis rierer sia, 55 Beara sees a ye ake aie 6
IV. PRINCIPAL PARTS LOCATION ....... 0.0... eee ec eens 7
V. VOLTAGE CONVERSION ........ 0... cee etree 8
VIL -ADJUSTMENTD 2: a6 shoe beeen aE sna Bb sce ge 6 Ga Me braves RS ee ws 9
Vil. CLASSIFICATION OF VARIOUS P.C BOARDS .................06. 10
1. P.C BOARD TITLES AND IDENTIFICATION NUMBERS........... 10
2. COMPOSITION OF VARIOUS P.C BOARDS .................-.-. 11
For basic adjustments, measuring methods, and operating principles, refer to GENERAL TECHNICAL
MANUAL.

lI. TECHNICAL DATA
ee
A
ne
INPUT SENSITIVITY/IMPEDANCE/SIGNAL
TO NOISE RATIO (IHF “A”)
PHONO 1
PHONO 2
TUNER
AUX
TAPE PLAY 1/2
OUTPUT LEVEL/IMPEDANCE
TAPE REC 1/2
OUTPUT
RATED LOAD IMPEDANCE
PHONO MAX. INPUT LEVEL (1 kHz)
PHONO 1/2
FREQUENCY RESPONSE
TUNER/AUX/TAPE PLAY 1/2
PHONO 1/2 (RIAA curve deviation)
TOTAL HARMONIC DISTORTION
(20 Hz to 20 kHz)
TUNER/AUX/TAPE PLAY 1/2
(Volume Max.)
PHONO 1/2 (Volume Max.)
TONE CONTROL
BASS
TREBLE
SUBSONIC FILTER
CHANNEL SEPARATION (AUX)
SEMICONDUCTORS
POWER REQUIREMENTS
POWER CONSUMPTION
DIMENSIONS
WEIGHT
MM: 3 mV/33 k, 47k, 100 kohms/82 dB
MC: 0.08 mV/10 ohms/75 dB
MM: 3 mV/47 kohms/82 dB
150 mV/47 kohms/102 dB
150 mV/47 kohms/102 dB
150 mV/47 kohms/102 dB
150 mV/600 ohms
1 V/600 ohms
47 kohms
400 mV (MM)
5 Hz to 100 kHz + 0.5 dB
30 Hz to 15 kHz + 0.2 dB
0.005% at output 10 V
0.005% at output 10 V
+8 dB at 100 Hz
+8 dB at 10 kHz
12 dB/oct. at 18 Hz
70 dB (shorted circuit)
Transistors 29, Diodes 48, FETs 2, ICs 11
120 V, 60 Hz for USA and Canada
220 V, 50 Hz for Europe except UK
240 V, 50 Hz for UK and Australia
110/220/240 V, 50/60 Hz internally
switchable for other countries
U/T, AAL, CSA Models: 20 W
440 (W) x 78 (H) x 313 (D) mm
(17.3 x 3.1 x 12.3 inches)
6.3 kg (13.9 Ibs)
* For improvement purposes, specifications and design are subject to change without notice.

I. DISMANTLING OF UNIT
In case of trouble, etc. necessitating dismantling, please dismantle in the order shown in the photographs. Reassemble
in reverse order.
: —me
1HU... 8 SS eC ss
x 35 eo
SCREWS
SCREWS
Sap
aa
SCREWS
FRONT PANEL
UPPER COVER

ON AARWN 3
CONTROLS
POWER SWITCH
BASS CONTROL
TREBLE CONTROL
FILTER SWITCHES
MODE SELECTOR .
LOUDNESS SWITCH AND !NDICATOR
LED dB VOLUME INDICATOR
VOLUME CONTROL
REMOTE CONTROL INDICATOR
INPUT SELECTOR INDICATOR
INPUT SELECTOR
PHONO SELECTOR
REC (Recording) SELECTOR
STEREO BALANCE CONTROL
15.
17.
18.
20.
21.
22.
23.
24.
25.
26.
27.
S2FUAL NUMBER
Aa EL COU. RL am
‘SHOCK AATARE - 8D NOT EFER/
RISOBE BE CROC - HE PAS CMREVER
SERURAORSSEEFARR-—“HICST GFFMEN /
CARTIBW: in coe of use ourside of indicated
service
power source arse, conmét’our
Shop for necessary conversion.
200W MAX. Tova, TOOW MAX
Ac 110-2400
80/60Hz 20W
Fig. 1 Controls
CAPACITANCE CONTROL
GROUND TERMINALS
TUNER JACKS
AUX JACKS
TAPE 1 SYSTEM REC/PLAY JACKS
REMOTE CONTROL JACK
TAPE 2 SYSTEM REC/PLAY JACKS
OUTPUT JACKS
AC OUTLETS (Some models are not equipped with this facility.]
AC CORD (Some models are equipped with an AC Inlet instead of
an AC cord. Connect with an appropriate power cord.)
TAPE 1 SYSTEM DIN JACK (Some models do not have this facility’-)
PHONO 2 INPUT JACKS
PHONO 1 INPUT JACKS

IV. PRINCIPAL PARTS LOCATION
MODE SWITCH
Swi
TREBLE CONTROL LED PC BOARD(A)
VRI PRA-6O00IC
SUBSONIC HIGH VOLUME DOWN SWITCH
Ssw3 sw4 SWITCH P,C BOARD
Sw2 PRA-6025
FILTER
BASS CONTROL SWITCHES LOUDNESS VOLUME UP
VR2 SWITCH SWITCH
sw2 swt
R FUSE POWER PRE AMP
P.C BOARD TRANSFORMER P.C BOARD
PRA-6022(U/T) T90I PRA-6001A
POWER
SWITCH
Sws0i
eecticeaialiny { Scie
TONE CONTROL
P.C BOARD
PRA-4002A
LED VOLUME INDICATOR
DSO
REMOTE LAMP
P.C BOARD
PRA-6026
FETYETIVTVIFITTTY,
VOLUME BLOCK
(VR2-ito5,SW4-1,2)
REC SELECTOR
SWITCH
sw3 swi
LED P.C BOARD(B)
PRA-4002B
PHONO SELECTOR
SWITCH
Swi
INPUT SELECTOR
SWITCH
Fig. 2 Front View
INPUT SELECTOR
P.C BOARD
PRA-6001B
Fig.3 Top View

V. VOLTAGE CONVERSION
SCREW
A
POWER SWITCH
oce
\
REAR
Fig.4 Voltage Conversion (U/T Model)
1. U/T MODEL (Refer to Fig. 4)
1. Switch off the power supply and remove the plug
from the mains supply.
2. Loosen holding screws and remove the top panel.
3. Remove the screw holding the Fuse P.C Board
located near the power transformer.
4. Remove existing Line Voltage Fuse and insert
required Line Voltage Fuse in the proper fuse
holder.
110V : 800mA 250V
220V : 400 mA 250V
240V : 400 mV 250V
2.
MODEL
OTHER
THAN
U/T
No voltage conversion.
Scere
enn
sneererverevaiienreeeset
8

Vi. ADJUSTMENT
DC CENTER OFF-SET
VOLTMETER VOLTAGE
aa
PRE AMP P,C BOARD PRA-600IA
Fig. 5 Pre Amp P.C Board/Instrument Connection
CENTER OFF-SET VOLTAGE
ADJUSTMENT (Refer to Fig. 5)
Connect the Digital Voltmeter or DC Voltmeter between
the test points on the Pre Amp P.C Board PRA-6001A
and the ground.
Adjust VR1 (L-ch), VR1b (R-ch) | kB, so that the volt-
meter reads 0 + 0.5V.

Vi.
CLASSIFICATION
OF
VARIOUS
P.C
BOARDS
1. P.C BOARD TITLES AND IDENTIFICATION NUMBERS
P.C Board Title PC Board Number
Pre Amp P.C Board PRA-001A
Input Selector P.C Board
LED P.C Board (A)
Fuse P.C Board (E) (CSA, AAL)
Switch P.C Board PRA6025
Tone Control P.C Board PRA-4002A
LED P.C Board (B)
Balance P.C Board PRA-4042
Chart-1
10

2. COMPOSITION OF VARIOUS P.C BOARDS
1) PRE AMP P.C BOARD PRA-6001A and REMOTE LAMP P.C BOARD PRA-6026
1 2 REC PLAY
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a Sy
OUTPUT,
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ft vet
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vio.
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—
REMOTE
LAMP
Seana
PRA-4002A
P.C
BOARD
PRA-6026
1
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ah
4,
io}
lo
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io PRA-60018
io
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ta
WMO
PRA.4002A
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td
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pra-6022
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|
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PRA-6023
(CSA,AAL)
Vel
|
PRA-6024
(CEE
,UK,SAA)
i
bed
PRA-6025
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2)
TONE
CONTROL
P.C
BOARD
PRA-4002A
and
LED
P.C
BOARD
(A)
PRA-6001C
3)
INPUT
SELECTOR
P.C
BOARD
PRA-6001B
LOUDNESS
cao
vi6
LED PC BOARD (A)
PRA-600IC
PRA-4042
2 PRA-600IA Ff
| le PRA-GOOIA
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1
12 PRA-6OOIA
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4) SWITCH P.C BOARD PRA-6025
1
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PRA-60OIA
jee! Ras
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1891_24.9V
1
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|
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MONO
on
on
TONE
CONTROL
i
P.C
BOARD
[TREBLE] BASS
|
|
PRA-4002A
:
eee
HIGH
SUBSONIC
d
12

5) BALANCE P.C BOARD PRA-4042
BLK GRY GRY BLK J
6) LED P.C BOARD (B) PRA-4002B
PRA — 6001B
PRA- 600I1A
4
o 13
0 2 PRA-— 4002A
'
!
ye BOK set Sh NG ate act Ue oh
BALANCE
u 2
13

7) FUSE P.C BOARD (D) (U/T) PRA-6022
4 T901
PR-AO6T—70
i PRA-6OOIA
OUTLETS ert
y <r t
a BRN 110V ts ds eel ie
ACIIOV
to
240V
Fl 800mA 250V (110 Vv)
F2 400mA 250v (220v)
F3 400mA 250V (240V)
8) FUSE P.C BOARD (E) (CSA, AAL) PRA-6023
ft ad
0.047/400(K)
-O,
a oa
ci
3B 0.01/500(P) ~
:——7
~ 64 0.01/5008).”
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SOnz
PRA —600IA
PR-AQ6T-30
WARNING: AINDICATES SAFETY CRITICAL COMPONENTS. FOR CONTINUED SAFETY, |
REPLACE SAFETY CRITICAL COMPONENTS ONLY WITH MANUFACTURER'S
RECOMMENDED PARTS
AVERTISSEMENT: AIL INDIQU LES COMPOSANTS CRITIQUES DE SURETE. POUR
MAINTENIR LE DEGRE DE SECURITE DE L' APPAREIL NE REMPLACER LES
CONPOSANTS DONT LE FONCTIONNEMENT EST CRITIQUE POUR LA SECURITE
QUE PAR DES PIECES RECOMMANDEES PAR LE FABRICANT
14

9) FUSE P.C BOARD (F) (CEE, UK, SAA) PRA-6024
0.01/500(F)
—tr—
0.047/400(K)
C2 0.047/400(k)
e——1—_-e . e——~+1t—
C4
cl
3 0.01/500(P)
-—it—e
C6 0.01/5001P) -*
a la re
A\ T200mA
€8 0.01/800(P)._
a)
WHT 220V
(CEE)
BLU 240V
eqsE-R ya
1 it
pape eeiie a
1234
AC 220v AC 240V
PR-6OOIA SOHz SOHr
i i a
[Eee RE 4 [AC_iNLET]
A T901
PR~AO6T-40 (CEE)
PR-AO6T—50 (UK)
WARNING: AINDICATES SAFETY CRITICAL COMPONENTS. FOR CONTINUED SAFETY,
REPLACE SAFETY CRITICAL COMPONENTS ONLY WITH MANUFACTURER'S
RECOMMENDED PARTS 2 i
AVERTISSEMENT: AIL INDIQU LES COMPOSANTS CRITIQUES DE SURETE. POUR
MAINTENIR LE DEGRE_DE SECURITE DE L' APPAREIL NE REMPLACER LES
CONPOSANTS DONT LE FONCTIONNEMENT EST CRITIQUE POUR LA SECURITE
QUE PAR DES PIECES RECOMMANDEES PAR LE FABRICANT
15

SECTION 2
DC STEREO POWER AMPLIFIER
MODEL PA- W06
ALSO APPLICABLE TO BLACK PANEL MODEL
TABLE OF CONTENTS
I TECHNICAL DATA... os6.c8 eran a oe er eeree aS goo aed wala ale ee See 18
Tl. DISMANTLING OF UNIT... 2... 0. ce ee eee 19
TH: “CONTROUS 0535003) 5 Sccs6acesieccta acer e thee agit gua ayera's Wigan wae boo e OAR ay Sea 20
IV. PRINCIPAL PARTS LOCATION .......... 0... .. cece eee eens 21
V. VOLTAGE CONVERSION .......... 0... cece eee eee ences 22
VI. OPERATION OF PULSE POWER CIRCUIT ...............000 ces 23
VIL --ADJUSTMENT? 366065 0203 bos bb Se oa OA Seen ce ha pe eae hee 30
VIII. CLASSIFICATION OF VARIOUS P.C BOARDS ................... 31
1. P.C BOARD TITLES AND IDENTIFICATION NUMBERS........... 31
2. COMPOSITION OF VARIOUS P.C BOARDS ..............200005 32
For basic adjustments, measuring methods, and operating principles, refer to GENERAL TECHNICAL
MANUAL.
17

Il. TECHNICAL DATA
RATED POWER OUTPUT
(2-channel driven)
TOTAL HARMONIC DISTORTION
INTERMODULATION DISTORTION
SIGNAL TO NOISE RATIO (IHF “A”’)
RESIDUAL NOISE (IHF “‘A” at 8 ohms)
POWER BANDWIDTH (IHF)
DAMPING FACTOR (IHF)
FREQUENCY RESPONSE
INPUT SENSITIVITY/IMPEDANCE
OUTPUT
SPEAKERS
HEADPHONES
SUBSONIC FILTER
SEMICONDUCTORS
POWER REQUIREMENTS
POWER CONSUMPTIONS
DIMENSIONS
WEIGHT
68 watts per channel, minimum RMS, at 8 ohms from
20 to 20,000 Hz with no more than 0.008% T.H.D.
0.008% at rated power output
0.008% at rated power output
117 dB
0.05 mV
6 Hz to 60 kHz (at 8 ohms, T.H.D. 0.05%)
More than 100 (1 kHz 8 ohms)
DC to 100 kHz +0 dB, -0.5 dB
1 V/47 kohms
A, B (4 to 16 ohms)/A+B (8 to 16 ohms)
8 to 16 ohms
12 dB/oct. at 5 Hz
Transistors 27, Diodes 50, FETs 2, ICs 7
120 V, 60 Hz for USA and Canada
220 V, 50 Hz for Europe except UK
240 V, 50 Hz for UK and Australia
110/220/240 V, 50/60 Hz internally
switchable for other countries
U/T, AAL: 350 W
CSA: 250 W
CEE, UK: 450 W
440 (W) x 78 (H) x 373 (D) mm
(17.3 x 3.1 x 14.7 inches)
6.8 kg (15.0 Ibs)
* For improvement purposes, specification and design are subject to change without notice.
18

I. DISMANTLING OF UNIT
In case of trouble, etc. necessitating dismantling, please dismantle in the order shown in the photographs. Reassemble
in reverse order.
SCRE WS
SCREWS:
SCREWS
SCREWS
FRONT PANEL
UPPER COVER
SCREWS
19

ill, CONTROLS
ar 1.20 > ee wm v0
pe vb te bene to
ot .2e 7 @w mo 20
SPEAKER &,8(4:160), A+B (B-160)
[ ama + cg tlrT,.
ica} €
a
b
SHOCK HAZARS - 00 KOT aPEN/ .
TYSQRE BE CBOG - ME PAS ERLEYER /
SERHRROMESCE FARE - WCET OFFREM F
Fig. 1 Controls
1.
POWER
SWITCH
8.
DC/LOW
CUT
OPERATION
SWITCH
2.
HEADPHONE
JACK
9.
INPUT
JACKS
SPEAKER
SYSTEM
SELECTOR
SWITCHES
AND
10.
SPEAKER
OUTPUT
JACKS
FOR
A,
B
SPEAKER
SYSTEUS
INDICATORS
11.
EXTRACT
AC
OUTLETS
4.
METER
SWITCH
(Some
models
are
not
equipped
with
this
facility.)
5.
FLD
BAR
METER
12.
AC
CORD
(Some
models
are
equipped
with
an
AC
Inlet
isteacd
6.
CLIPPING
INDICATOR
of
an
AC
cord.
Connect
with
an
appropriate
power
cord.}
7. DC OPERATION INDICATOR
20

IV. PRINCIPAL PARTS LOCATION
METER SWITCH
sw!
LED P.C BOARD(B)
PAW- 40038
FLD BAR METER
INDI
POWER SWITCH LED P.C BOARD(C)
Swsol PAW-6001
ee
Eis q
OPERATION SWITCH
swl
HEADPHONE
A
B
LED
P.C
BOARD(A)
JACK
sw2
Ssw3
PAW-4002B
SPEAKER
SWITCHES
Fig.2 Front View
RECTIFIER P.C BOARD(A)
MAIN AMP RC BOARD
PAW-4043(U/T)
PAW-4001 T90I
sub
ot
ad hs envace lease
PULSE POWER
SUPPLY BLOCK
(PULSE POWER
SUPPLY P.C BOARD
AMU-6004A)
hoe ie yt te et jas
SWITCH PC BOARD
PAW-4003A
FILTER P.C BOARD
PAW-4002A
Fig.3 Top View