Accuphase P 266 Schematic

Page 1

CIRCUIT ADJUSTMENT (@Efiéfiifé)

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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

i-�J--�wlfiélii'x htfivf -�/ lmf/a- l 33-�779-�r -7 fléli'i-�Lfio-�CTé-�bm 1. fifiifili-fl-�flfl-�) OUT-F3-�.

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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EOPERATION SWECLASS. 1:

$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.
\"I'\'.\mifi'.1-�:32.25\"l:"; 5 ME I?!
AIL. 1-77. am dBk-Z'Eal'i
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)