Accuphase P 266 Schematic

Page 1

CIRCUIT ADJUSTMENT (@Efiéfiifé)

‘7' 7~.7—‘—l:l. 7x71337009 LII/3 {a fié‘filfiwl‘é‘w‘:

Note 2. Adjustments should be made in case of the PC Board or Transistors being changed.
flfifliPCrK— F '55 “Ii Is 5 ‘/ "x‘ Z 9 ’2 iii? L EIKIfi‘fi'o ”ET—E" L‘s

Note3. With 30 minutes interval after putting power swith 0N. repeat 1 to 4 adjustments.
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Noted.

test point with shorting connector jack.

INPUT SIGNAL PROCEDURE
STEP ADJUST ITEM A 73 1% s“; a? E I; a: ADJUST REMARKS
1777 is] g LOAD TEST EQ'PT CONNETING POINT ifilfiifi _ EH % ‘ ffi %
a Ts? Is It as IE ff: as i
POWER AMP ASSEMBLY (7I7-00I4-00)
Note 1. Internal input resistance of volt-ohm meter should be higher than 10kohms.

Adjustment is made at test point with shorting connector jack removed. After adjustment completed make sure to plug

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Normal Operation
I Bias Current for Lch.
Leh I “'4 Tlfifilf.

Normal Operation

VR 1
Power Amp Assembly

(711-0014410)

Power Amp Assembly
V.0.I\leter set

Adjust Ior 'XSITIII"
reading ol “0.11:!"
E0peralion mode set at XORIIAL
717—”lfidWC‘38mV‘ifiifi’1
fiOPERIITlOX SII'E'XORIIAL:

+7}

2 Bios Current for Rch. N0 Input (717-0014-00)
Rch Z “.4 7Xiiii g 7\ 7’ range to less than
DCO.3V _ .
0355.11 Operation No Load Txy— Betneen test pom:
3 Bias Current for LEI]. 5 1:1 fij 6%an

DC0.3VL1‘F7>V 9:; VR2
Power Amp Assembly

(71770014-00)

Lch:r<477~$a‘fi ixld-M‘xleefifl

CIEISS‘A Operation
4 Bias Current for Rch.
RclI Z 1"4’ 716.5%“

Adjust Int "30ml"

reading of \’.0,I\Ietzr
§0pmtinn node set at CLASSA

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$7,;

METER CALIBRATION (Located PROTECTION CIRCUIT ASSEMBLY 720-0007-00)

2‘ — 9 EEE
Notel. Adjustment should be repeated until correct meter indication is obtained.
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Note 2. Meter function switch is set at Normal position.

l—9—77‘J7’Ja 75M 7‘7‘I3NORMALFK‘799‘x’EON

Adjust input signal so that VTVII
reads 32.2w. Then adjust VRZ and
VIII so that Meter rud 0 dB.
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1:VR3,4€’3‘£¥.

Peak-I] dB VR3

l Calibration for Lch. Protection Circuit

' Lch 2 0 dB QUE Assembly
Peak-0 dB 1m; Sine Wave VR4

2 Calibration for Rch. . . Protection Circuit

2; e
RCII : 0 dB mi 115 i‘ '& Assembly
VTVM Speaker Terminals »

Linearity Adjustment N Load VR 1

3 - for Lch. 0 Protection Circuit -
fifi‘l’l‘i‘lfiffi 212 fi 'f'Jf Assembly
Linearity Adjustment VRZ

4 for Rch. Protection Circuit
Ififififilfllfi Assembly

Adiusl input signal so [hat ‘I'TVII

' reads 1.02Vi-30dBi. Then adjust

VIII and VR3 so that Meier reads
-3Ild8.

VTVIIQIfiiIEI .02\"3 ‘30dBE 2 ’57.» I1
11 In}: L _ I — ifllfi‘IzW-Slldfl':
’15 l 'i.’1\’Rl.2i'iIif.§

Lch. Power Amp Assembly
(717—9014—09) (717—0014—00) —

\ l/
/

VR 2
(ClaSS-A)

VR I
7 (Normal)

/ .
TE! :7"? ‘7 a f/Assernbly) VR 1
(720*0007—00)

VR 3
(—30dB) (OdB) (—30dB) (OdB)

VR2 VR4

L‘- Lch.5—' ‘— Rch. —’

Rch. Power Amp Assembly

VR I
(Normal)

VR 2
(Class-A)