Sony TC-777-2 User manual

Table of Contents
SPECIFICATIONS
BLOCK DIAGRAM
3
TECHNICAL FEATURE 4
CABINET — TOP VIEW
CABINET — SIDE VIEW Model 777-2/-4
6
CABINET-SIDE VIEW Model 777-2J/-4J 7
CHASSIS-TOP VIEW 8
CHASSIS-BOTTOM VIEW
9
METHOD OF DISASSEMBLING THE SET
10-11
MECHANICAL ADJUSTMENT 12-13
ELECTRICAL ADJUSTMENT
13-17
17
MODIFICATION TO DIFFERENT POWER LINE FREQUENCY
.... 18
LEVEL DIAGRAM
19-24
CIRCUIT SCHEMATIC MODEL TC-777- /- J
2 -32
MOUNTING DIAGRAM
33-38
CIRCUIT SCHEMATIC Model 777-2J/-4J
WIRING OF HEADS
39
40-48
EXPLODED VIEW
Page
2
SONY
SERVICING GUIDE

Specifications
4 track monophonic
Head Composition:
Inputs :
2
Outputs :
2
0 dbs (0.77 V)
1
1
outputs :
Motors :
Dimensions :
Weight:
2 -
1
1
1
Signal-to-Nolse Ratio:
Flutter and Wow:
Blas Frequency:
Recording Time:
(with 1,800 ft tape)
Power Requirements:
Tape Speeds:
Reel Size:
Frequency Response:
2 track monophonic
& 4 track stereo
1 hr 30 min
3 hrs
3 hrs at 7'/i ips (19 cm/s)
6 hrs at 3J4ips (9. cm/s)
1
1
1
1
1
1
2
IC- 24R, ;
UC-124R;
17*/, (W) x 177. (0) x 8'7..' (H)
(44 mm x 4 8 mm x 216 mm)
42 lb 14 oz (19. Kg)
AC 100, 110, 117, 12 , 220 or 240 Volts 0/60 Hz, 90 Watts
7% ips and 3?4 ips
Up to 7* (18 cm)
±2 db 40-16,000 Hz at 7% ips (19 cm/s)
0-9,000 Hz at 3?; ips (9. cm/s)
Better than 0 db (at peak recording level)
Less than 0.1% at 7>4ips (19 cm/s)
Approx. 92 KHz
2 track stereo
tc -777:V:4 j j
Line ...........................................................
Model 777-4
high impedance (100 KQ)
-12 dbs (0.22 V)
Model 777-2 and 777-2J -4J
high impedance (100 KQ)
-10 dbs (0.2 V)
Line Outputs .....................................
low impedance (600 Q)
high impedance (10 KQ)
Stereo monitor ...............................
high impedance (10 KQ)
Model 777-2J -4J
Record/Playback Connector
inputs: load impedance 100 KQ
-33 dbs (0.02 V)
load impedance 100 KQ
-3 dbs (0.68 V)
HC-634D, ; Capstan ..........................................
Reel ....................................................
Reel ....................................................
4 min
k 1 hr 30 min
Model 777-4 -4J
ERP24 2902; 4 track erase/4 track record
PP30-4202LNS ; 4 track playback ...................
PP30-2802LN ; 2 track playback ...................
Model 777-2 -2J
ERP24-2202 ; 2 track erase/2 track record
PP30-2802LN ; 2 track playback ...................
PP30 4202LNS ; 4 track playback ...................
Microphone ..........................................................................
Model 777-4
low impedance (2 0 — 600Q)
-72 dbs (0.2 mV)
Model 777-4J
low impedance (2 0 — 600Q)
-60 dbs (0.7 mV)
Model 777-2
low impedance (2 0 — 600Q)
-68 dbs (0.3 mV)
Model 777-2J
low impedance (2 0 — 600Q)
-60 dbs (0.7 mV)

CH 1
CH 1
Mic Pre -Amp
Record Equalizer
Record Amp
Mic
Bias Oscillator
X-..;: -.o;
Playback
6
Playback
CH-1
Line Out Amp
■©
Track Selector
Equalizer
Line Out
Selector
Channel -2
VU
(Same as Channel - 1 )
Power Rectifier
Voltage Selector
AC
D
t
Tape Transport
Control Circuit
If
TC-777
CH-l
Record Equalizer
REC H
Record Amo
Bias
CH-l
E H
Oscillator
Bias ON/OFFSW
Line-Out Amp Track Selector
VU
Channel -2
AC
i
(Same as Channel 1)
Power Rectifier
3
Block Diagram
StiS OsCil'atCr
Record Amp
Line Out Amp
Playback Amp
Mic Pre-Amp
Playback
Equalizer
Selector
Tape Transport
Control Circuit
CH 1
REC H
Bias Oscillator
Record Amp
Line -Out Amp
Pla/bac* Amp
Mic Pre-Amp
CH-1
4 track
P B H
CH-l
2 track
P.B H
CH-l
2 track
P B.H
CH i
4 track
P B.H,
CH 1
E H
Playback
X
S ’
g
o ----------------- •
Bias ON/OFF SW
Tape
Source
Moni SW L
TC-777z<j
Xioi tc«
Pre Amp
Xios tot
tape
Source
Mon. SW
X ioi io ?
CH-l
©-
Line input
ch
Mic input (O q
tc -777:1/ i ;
input
CH-l
’ ^9) Loe-Out
Line input
117V
IIOV
— — 0

Tape Transport Mechanism
Head Arrangement
The Head Assembly consists of three Heads with the following stack arrangement:
f
TC777-2/-2J
2 Track Playback
4 Track Playback
PP30-2802LN
PP30-4202LNS
TC777-4/-4J
— 4 —
Technical Feature
□rm
den
SONY Model 777 Series Stereo Tapecorders are high quality precision instruments for professional
three Heads, three Motors, all transistor Amplifiers and perfect push button operating system.
2 Track Erase
/2 Track Record
ERP24-2202
4 Track Erase
/4 Track Record
ERP24-2902
2 Track Playback
PP30-2802LN
4 Track Playback
PP30-4202LNS
TC-777in
The head located at left is Electro-Bi-Lateral Head which Two (Four) Track Erase Head and Two (Four) Track Record Head
are enclosed in one shield case. Two Track Playback Head and Four Track Playback Head are perfectly shielded with the
permalloy-copper-permalloy shield cases.
use provided with
The tape transport mechanism is operated electrically with three Motors, two Solenoid Plungers and three Relays switch 
ing the Motors and the Plungers.
For driving the capstan, Hysteresis Synchronous Motor, whose rotation synchronizes perfectly to power frequency and is
not influenced by power voltage change, is used Speed change is available by changing numbers of the pole, viz. 4 poles
for 19cm/sec (7-1/2 ips) and 8 poles for 9. cm/sec (3-3/4 ips). For Feed Reel Motor, Eddy Current Motor with outer
rotor is used and gives proper back tension to the tape with low voltage operation in Forward Mode and rewinds the tape
with high voltage operation. For Take up Reel Motor, 4 Pole Induction Motor is used and operated with low voltage
in Forward Mode and with high voltage in Fast Forward Mode.
Brakes of Take-up and Feed sides are released when a Solenoid Plunger is pulled, and Pinch Roller is pressed by ano 
ther Solenoid Plunger.

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1C-777
Aios) Detachable Hinge
Fuse, 2. A
------ (193 ))Name plate
(CNSJ a C Outlet
Alt) 2) Cabinet Sash
A10- ) Lid Catcher
Line Input Jack IJ
u*t c«>r
MIC Jack
---- (S«2
(Fig. )
6 —
Cabinet Side Views
Remote Control
Connector
Screw, @ RF3 X 6
4PCS
Screw.
©T3X2
Jack Panel; 3
4
AC Connector (CNloi) 4
•(J m ?) Binaural Jack
TC-777.;/:;;
Washer Z"X
Screw ("10-22) ------
©RK4X20 '
each 4PCS
Lid Catcher uliM I- -----
<. ‘ 03 \ .
----- *-ine J acl<
Switch,
Impedance Selector
©Rubber Fool 8PCS
Screw
©RF3X8
6PCS
M,c Se £K<S>
— I36 l) jacl ' Panel
A, .X Washer
------------ Screw © RK4 X 20
each 4PCS

Fuse, 2. A (F301Y
Aus') Detachable Hinge
Name Platen 93
I
AC Connector {CN306J
A1Q2J Cabinet Sash
A] 0.22'
AlO-s) Lid Catcher
Jack Panel (3 — 2
Jack Panel
.36-2.
,A|03 o )
— 7 —
' UH!
I
Washer
Screw ©RK4X20
each 4PCS
Lid Catcher (A10-
Screw
©RF3X8
Washer
A10-22) a . Screw ©RK4X20
v — each 4PCS
Rubber Foot
8PCS
Screw
©T3X2
{CN^JAC Outlet
TC-777:^
TC-777L ”
.(CNtOl) Rec/P.B Connector
— (J40s) Binaural Jack
Line Input Jack
® ) Screw. © RF3 X 6
4 pcs
MIC Input Jack(??
Remote Control (QHjjs).
Connector V z
/^xLine Output Jack^ F ' g ' 6 ’
\U04/
,Z x Switch
(S402) Impedance Selector

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(1)
Removal of Mounted Circuit Board
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- 9 —
Method of Disassembling the Set
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(2)
( 3 )
( 4 )
Power Supply and Oscillator Circuit Board
Remove two Screws (©B 2.6X12 marked with A in Fig. 13) and two 2.6$ Spring Washers.
( 1 )
(2)
( 3 )
(4)
( 1 )
( 2 )
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Equalizer Amplifier Circuit Board Channel-1
Remove three Screws (®B 2.6x6 marked with A in Fig. 16) and three 3( Spring Washers.
Circuit Board Channel-2 is the same as Channel l.
Blas Adjustment Circuit Board
Remove four Screws (©B 2.6x12 marked with A in Fig. 13) and four 2.6( Spring Washers.
Removal of Control Panel
Remove two MIC Input Control Knobs. Line Input Control Knobs, Playback Control Knobs, one Instant Stop Button
Guard and four felts by loosening respective Set Screws as shown in Fig. 11.
Pull out Record Button Guard.
Loosen four screws (©RK3X20 marked with ® in Fig. 11).
Lift up the Panel gently.
Removal of Cabinet
Turn up-side down the recorder on a soft pad.
Pull out the Defeat Plug located on the bottom and Fuse Post Cap located on the right side.
Remove eight screws (©RK4x20 marked with a in Fig. 9) and eight Ornamental Washers as shown in Fig. 9.
Lift up the Cabinet gently.
Removal of Reel Panel
( 1 ) Remove four Screws (©8 3x6 marked with ▲ in Fig. 10) and four 3$ Panel Washers as shown in Fig. 10.
( 2 ) Remove Reel Panel and check main mechanism.
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Pro-Amplifier Circuit Board Channel-1
( 1 ) Remove five Screws (QB 2.6x6 marked with i in Fig. 8) and five 3< Spring Washers.
( 2 ) Circuit Board Channel-2 is the same as Channel-1.
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Removal of Sub Chassis
( 1 ) Remove six Screws (©RF3X6 marked with • in Fig. 12) and six 3< Spring Washers shown in Figl2.
( 2 ) Slide the Sub Chassis leftwards as shown in Fig. 12.
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AScre*
has been exactly adjusted
is replaced, as it
<? Reel Panel
( 3 )
ruse Post Cap
Mode, or after replacing a Brake Band, if the brake function is
(Fig. 9)
is pulled)
(Fig. 10)
( 4 )
( 1
14 oz
(2.2 kgs) — Torque: 67. oz-inch (4.840 gr-cm)
l Fig. 12)
III
■» — I
l/capsi an shaft
(Fig. 13)
— 11 --
12 -
(Fig. 14)
[Mechanical Adjustment
PP30 itZOZLNS ’ l
) I
Tinted Circuit Board
Power Supply & Oscillator -
(1)
( 2 )
( 3 )
( 6 )
( 7 )
( 1 )
( 2 )
(3 )
( 1 )
( 2 )
TC7Z7 4/4 j 3
11 fCZ/7 2/2J ‘ ,-|
Align the upper edge of each head Core
and the upper edge of the Tape
— ’ • iA.'imuin Alignment Screw
< - - RF3X4
<?
t
t.
TC-77711;
lit
I flr
Tc-777:;/::;
O.O7 mm
1. 3mm
0.07 mm
Tape Guid eul/)-
Elevation Alignment
Adjustment of Heads is unnecessary except the case Head or Tape Guide
at the factory. If replaced, adjust as follows (Refer to Fig. 14)
■ ’ RF 6 Vct
R W Srt. /
\ a 6 PCS . ,.Z
24 •, Prir 'ted Circuit Board
'. i Bias Adjustment)
_(C? r 7l' 1 Trimmer Capacitor
'<^'30- 200PF
Z^xBias Adjustment Coil
AfW/ ’ l mH
Screw . ‘ -,2.6x12
Spring Washer 2.6
each 4PCS
•Sere*
‘ S ’ ©RK3X20
B 4 PCS
AScrew
©RK4X20
8PCS
<39 ‘ Pla lc , Head Apron
Screw I..B2.6 x 1 2
Spring Washer 2.6/
each PCS
^^HERP24 2902^^^H pP3 ° 2802LN
^■(ERP24 2£O2jHBi-^)
. A J Height Alignment Screw
W/Hexagonal Hole. 3x
Ornamental Washer
8PCS
Brake Adjustment
When the machine is set to Stop Mode from other
loose, check as follows. (Refer to Fig. 1 )
Set the Recorder in Playback Mode. (Brake Solenoid Plunger
Loosen four Screws +RF3x6 marked with and 4-RF3X8 marked with O
Adjust the Spacing between the Brake Drum and Felt Lining to approximately 1/2 inches (1mm) by sliding the
brackets.
Loosen one Screw +RF4X10 marked with A in Fig. 1 of the Take-up side and move the Spring Holder Lug to
upper side.
Place a Test Hub (or empty reel with 44 mm^ hub) connected to Tension Gauge on Take-up Reel Table and pull
the Tension Gauge.
Reading on the Tension Gauge should be approximately 4 lb
Adjust Feed Reel side in the same way as Take-up side.
Thread a tape.
Align the upper edge of 4 Track (or 2 Track) Record Head Cores, 2 Track Playback Head Cores and 4 Track Play 
back Head Cores to the upper edge of the tape by turning each of the Height Alignment Screws with Hexagonal Hole
(3x marked with a in Fig. 14), and each of the Three Heads must be parallel to Capstan Shaft.
Turn the Height Alignment Screws with Hexagonal Hole of only 4 Track Erase/4 Track Record Head and 4 Track
Playback Head counter clockwise by approximately 4 ° from the position obtained in the preceding process, so
that the upper edge of the tape is approximately 0.07 mm (0.02 mm) higher than that of the Record Head Cores.
Tape Holdback and Take-up Tension Adjustment
Tape holdback and take-up tensions are adjusted by the sliding contact on the Resistor R,„ (upper side is for 0 Hz
and lower side is for 60 Hz) located on the base plate above the Feed Reel Motor. (Refer to Fig. 8)
Place a Test Hub (or empty reel with 44 mmd hub) connected to Tension Gauge on Feed Reel Table.
Set the recorder in Playback Mode and read the Tension Gauge while pulling it.
Tension Gauge should indicate 10.6 oz (300 grs). Torque: 9.2 oz-inch (660 gr-cm)
If the specified value is not obtained, adjust R 303 .
Screw 2 6 12 1
Spring Washer 2.6/
each 2PCS
Printed Circuit Board '
3P Connecter