Harris 994 6690 003 User manual

TECHNICAL MANUAL
INTEGRATED CIRCUIT TURNTABLE PREAMPLIFIER
994 6690 003
March
19 7 7
Technical Man al // 888 1712 001
Printed:

LIST OF EFFECTIVE PAGES
TOTAL NUMBER OF PAGES IS AS FOLLOWS: 15
PAGE NO.
I SSUE
PAGE NO.
I SSUE
*
ii
Original
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Blank
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Original
5-2
5-3 through 5-4
Title Page
List of Effective Pages .
iii
1- 0 through 1-2
2- 1 through 2-2
3- 1
3- 2
4- 1 through 4-3
4-4
THE ASTERISK INDICATES PAGES REVISED, ADDED OR DELETED BY THE CURRENT CHANGE.

TABLE OF CONTENTS
Paragraph
Page
SECTION I.
GENERAL DESCRIPTION
1-3.
INSTALLATION AND OPERATION
SECTION III. MAINTENANCE
PARTS LIST
SECTION IV.
SECTION V. DIAGRAMS
Introd ction
LIST OF TABLES
Page
Table
1-1. Electrical and Mechanical Characteristics
LIST OF ILLUSTRATIONS
Page
Fig re
1-0
Integrated Circ it T rntable Preamplifier
5-3Z5-4
5-1.
Integrated Circ it Phono Pre-Amp Schematic
iii
Disconnect primary power prior to servicing.
WARNING:
3-1.
3-3.
4-1
4-1
Introd ction
Electrical and Mechanical Characteristics
Introd ction ..
Tro bleshooting
Introd ction
Replaceable Parts Service
3-1
3-1
2-1
2-1
2-1
2-1
2-2
SECTION <11.
Introd ction ......
Mo nting
Inp t Connections .. .
O tp t Connections ..
Power Connections ...
Circ it Description .
4-1.
4-3.
CM
r — I
2-1.
2-3.
2-5.
2-7.
2-9.
2-11.

EQUALIZED PREAMPLIFIER
AUDIO
r-OUTPUT — |
INPUT
117VAC
LEVEL
Figure 1-1.
ro
Integrated ircuit Turntable Preamplifier
1-0
Disconnect primary power prior to servicing. WARNING:
FUSE
INTERNAL
r-

SECTION I
GENERAL DESCRIPTION
INTRODUCTION.
1-1.
1-3.
ELE TRI AL AND ME HANI AL HARA TERISTI S.
1-4.
CM
1-1
Disconnect primary power prior to servicing.
WARNING:
This man al contains all information necessary to install,
and maintain the Integrated Circ it T rntable Preamplifier, part
Fig re 1-1 shows the front view of the eq ipment
1-2.
operate ,
n mber 994 6690 003.
s pplied.
Table 1-1 lists the electrical and mechanical characteristics
of the Integrated ircuit Turntable Preamplifier.

Electrical and MECHANICAL Characteristics
Table 1-1.
CHARACTERISTIC
FUN TION
47,000 ohms
Inp t Impedance
Maxim m Inp t
O tp t
Response
Distortion
Noise
Load Impedance
0° to +60° C
117/234 volts, 50/60 Hz, 1 watt
Power
Mo nting
Size
Weight and C bage
1-2
WARNING:
Disconnect primary power prior to servicing.
Operating Ambient Temperat re
Range
At least 85 dB below +15 dBm o tp t,
20 Hz to 20 kHz.
150 mV at 1 kHz (clip point), 60 mV
at 1 kHz (+15 dBm o tp t)
600 ohms or 150 ohms, flating for
gro nded or ngro nded loads.
7-7/16 inches long, 3-1/8 inchs wide,
2-1/16 inches high
Less than 0.5% at +15 dBm o tp t,
50-15,000 Hz
-2 dBm with 9 mV inp t at 1 kHz
(typically cartridge level)
Within +1 dB of RIAA/NAB standard
c rve
Net weight, 1 lb. Packed weight, 8 lbs.
C bage: 1 c bic foot.
Two holes for mo nting to Harris t rn 
table or inside of any cabinet. May
be mo nted in any position.

SECTION II
INSTALLATION AND OPERATION
2-1.
INTRODUCTION.
2-3.
MOUNTING.
2-5.
INPUT ONNE TIONS.
1,
the inp t terminals, 1 and 2.
2-7. OUTPUT CONNECTIONS.
2-9.
POWER CONNECTIONS.
Disconnect primary power prior to servicing.
WARNING:
r — i
2-8.
lines .
(the red wire to 4 and the black wire to 7).
and TB1-6.
Plug the line cord into any standard outlet providing 117 Vac
No switch is provided since the power consumption is 1 Watt.
For 234 Vac
jumper J2 to
Output connections are provided for both 600 ohm and 150 ohm
For 600 ohm operation, connect the output line to TB1-4 and TB1-7,
Place a jumper between TB1-5
For 150 ohm operation, connect the output line to TB1-4 and
TB1-5, (the red wire to 4 and the black wire to 5). Place jumpers between
TB1-4 and TB1-6 , and between TB1-5 and TB1-7. The Output Level ontrol
provides a means of adjusting the level of the preamplifier to match the re 
quirement of the following equipment.
2-10.
+io% 50/60 Hz. i: ___ ... ______________________________ _■
Dress the power cord away from the a dio lines for minim m h m.
operation, remove j mpers JI and J3 on the PC board and add new
the PC board.
2-2. This section contains information for installing and operating
the Integrated Circ it T rntable Preamplifier. Refer to Section V for the
schematic diagram that s pports the following disc ssion.
2-6. This Preamplifier is designed to work with any of the pop lar
moving-magnet cartridges. It is recommended that the high side of the
cartridge be connected to terminal No. 2, the low side to terminal No.
and the cable shield to terminal No. 3 of TB1. The impedance (47k ohms)
may be modified by changing the val e of R7 on the PC board. This sho ld
be done only in special cases, to s it non-standard cartridges. A high
freq ency scratch filter may be added by placing a 5000-20,000 ohm resistor
across
2-4. The Preamplifier is mo nted with two No. 10 self-tapping screws,
located on 3-3/4 inch mo nting centers. The nit is intended for vertical
mo nting, with the line cord down (other mo nting positions may be sed).
Add-on nits for stereo are mo nted by placing the second nit's cover over
the special top-hat rivets on the bottom side of the first nit, and slid 
ing to engage the rivets in the holes.

IR UIT DES RIPTION.
2-11.
NOTE
2-2
Disconnect primary power prior to servicing.
WARNING:
bo
2-12. The internal power transformer, Tl, provides voltage for a f ll
wave bridge, which prod ces an nreg lated positive and negative 24 Vdc.
These voltages are series reg lated by U2 and U3 to provide a reg lated
+15 Vdc. The inp t signal from the cartridge is voltage-amplified by the
IC (Ul), amplified by the c rrent-boosters (Ql and Q2) , which then drive the
o tp t transformer (T2) thro gh control R18. The R1AA C rve is prod ced by
means of negative feedback o tp t of Ql and Q2 to the other inp t of Ul.
In strong RF fields it my be necessary
to modify the gro nding. Install a
solder l g nder the screw above and
to the left of terminal No. 1. Termi 
nate the inp t and o tp t cable shields
at this point keeping the shield con 
nections as short as possible.

SECTION III
MAINTENANCE
INTRODUCTION.
3-1.
TROUBLESHOOTING.
3-3.
Sho ld
OUTPUT CONNECTIONS
Normal
CARTRIDGE - Replace if o tp t obtained with oscillator b t
d.
line cord.
e .
g.
CN
3-1/3-2
Disconnect primary power prior to servicing.
WARNING:
POWER SYSTEM - AC s pply dead, blown f se, or objective
Check o tp t of Tl, DC across C18 and C19 and Pin 2 of U2 to
gro nd and Pin 2 of U3 to gro nd as shown in fig re 5-1.
SIGNAL VOLTAGES - A sensitive AC VTVM is req ired, also
record these readings for f t re tro bleshooting.
CIRCUIT VOLTAGES - With normal operation the voltages on
Record the
b.
gro nd connects to amplifier gro nd.
a 12 mV for normal o tp t, at 1 kHz.
c.
not with the original cartridge.
TRANSISTOR AND IC - S bstit te new ones if no tester is
available or the original transistors show defective on test.
INPUT CONNECTIONS - One side is gro nded, be s re cartridge
Feed inp t from oscillator at -40 dBm
3-2. This section provides information for servicing the Integrated
Circ it T rntable Preamplifier.
3-4. The Preamplifier has received a thoro gh factory check,
tro ble be enco ntered, check the following:
f.
the schematic will be obtained, +20% with an acc rate meter,
voltages on the Unit for f t re se.
a. OUTPUT CONNECTIONS - Co ld be loose or shorted,
o tp t may be heard with phones with proper operation.

SE TION IV
PARTS LIST
INTRODUCTION.
4-1.
NOTE
REPLACEABLE PARTS SERVICE.
4-3.
CM
4-1
Disconnect primary power prior to servicing.
WARNING:
Act al component val es may vary slightly
from component val es listed on schematics
and parts lists. D e to ind stry-wide
shortages, it is sometimes necessary to
se parts other than those specified. In
every case, however, a s bstit te part is
selected for conformance to overall design
specifications so that eq ipment performance
is not affected.
4-4. Replacement parts are available 24 ho rs a day, seven days a
week from the Harris Service Parts Department. Telephone [phone] to
contact the Service Parts Department or address correspondence to Service
Parts Department, Harris Broadcast Prod cts Division, Harris Corporation,
123 Hampshire Street, Q incy, Illinois 62301 USA.
4-2. This section provides description, reference designator and
order n mber for selectable replaceable parts for proper maintenance of
the Integrated Circ it T rntable Preamplifier. Refer to table 4-1.

Integrated Circ it T rntable Preamplifier - 992 4820 001
Table 4-1.
HARRIS PART NO.
DESCRIPTION QTY.
REF. SYMBOL
500 0911 000
Capacitor, 750 pF, 500V, 5% 1
Cl
500 0902 000 Capacitor, 3300 pF, 500V, 5%
C2 1
526 0048 000 Capacitor, 10 F, 20V, 20%
C3,C4,C5
3
500 0759 000
Capacitor, 100 pF, Mica 1
C6
516 0375 000
Capacitor, .01 F, 50V
3
C7,C8,C9
526 0048 000 Capacitor, 10 F, 20V, 20% 1
CIO
516
0375 000
.01 F, 50V 1
Cll
Capacitor,
4
.003 F, 1 kV, Disc C12 thr C15
516 0067 000
Capacitor,
C16.C17
2
516 0393 000
.025 F, 500V, Disc
Capacitor,
C18.C19
522 0394 000 Capacitor, 100 F,
2
50V
CR1 , CR2 384 0255 000
2
Diode, MZ2360
CR3 384 0618 000
Rectifier, Bridge
1
F se, 1/10 Ampere 1
Fl
398 0337 000
LI
915 1181 001
1
Ind ctor Assembly
QI
380 0320 000 1
Transistor, TIP-29
Q2
380 0188 000 1
Transistor, TIP-30
1/2W, 5%
R1
540 1195 000
16k ohm,
1
Resistor,
R2
1/2W, 5%
540 1152 000
1
75k ohm, Resistor,
910k ohm, 1/2W, 5%
R3
540 1221 000
1
Resistor,
R4
2200 ohm, 1/2W, 5%
540 1182 000
1
Resistor,
R5
51k ohm, 1/2W, 5%
540 1202 000
1
Resistor,
R6
910k ohm, 1/2W, 5%
540 1221 000
1
Resistor,
Resistor, 100 ohm, 1/2W, 5%
R7 540 1102 000 1
4-2
Disconnect primary power prior to servicing.
WARNING:
ND

DESCRIPTION
HARRIS PART NO.
QTY.
REF. SYMBOL
Resistor, 3600 ohm, 1/2W, 5%
540 1179 000 1
R8
Potentiometer, 10k ohm, 1/2W, 10% 550 0626 000
R9
1
1/2W, 100 ohm, 5%
540 1102 000
RIO
Resistor ,
1
3600 ohm, 1/2W, 5%
540 1179 000
1 Resistor,
Rll
100 ohm, 1/2W, 5%
R12,R13,R14 540 1102 000 3
Resistor,
10 ohm, 1/2W, 5% R15.R16 540 1151 000
2 Resistor,
100 ohm, 1/2W, 5% 1 R17 540 1102 000
Resistor,
Potentiometer, Ik ohm, 1/4W, 10%
R18
1 550 0387 000
1 T1
472 0713 000 Transformer, Power
478 0398 000
1 T2
Transformer, O tp t
614 0542 000
TB1
Terminal Board, 7 Terminals 1
U1
382 0459 000 Integrated Circ it, LF356N 1
U2 1
382 0359 000 Integrated Circ it, MC7815CP
U3 382 0360 000 1
Integrated Circ it, MC7915CP
402 0129 000
2 XF1,XF1A
Clip, F se 102068
XU1 404
0304 000
Socket, Integrated Circ it, 8 Pin
1
939 2346 001 1
Printed Board Assembly
cm
4-3/4-4
Disconnect primary power prior to servicing. WARNING:
Table 4-1. Integrated Circ it T rntable
Preamplifier - 992 4820 001 (Contin ed)

SECTION V
DIAGRAMS
INTRODUCTION.
5-1.
TITLE
FIGURE
PAGE
5-375-4
Integrated Circ it Phono Pre-Amp Schematic
5-1
CM
5-1/5-2
Disconnect primary power prior to servicing.
WARNING:
5-2. This section contains the schematic diagram for the Integrated
Circ it T rntable Preamplifier

I
< R1 4
S 100
TB 1
I
-O 7
T2
2 RED
IF
-O 6
OUTPUT
IF
J
O 5
IF
-O 4
BLU
I
8
2
5
6
LI
3
I
I __ __
1
I
TBl
2
INPUT
I O-
COMMON
3
Tl
•15V • 24 V
2
El
3
J ( I )
r
Jl 3)
-I5V
_L
TOP FOIL ON PC BOARD
23
5
-24V
UNLESS OTHERWISE NOTED.
5-3/5-4
SHIELD
GROUND
-6-
E2
R2
75K
R4
2 2K
R3
9 I OK
rr cio
- 1 /2
CH
1
-L C7
. 1
R9
I OK
DC OFFSET
ADJUSTMENT
R8
3 6K
CRI
M 2236
RI5
1
RI6
1
RI7
1
U2
LM 34 1-15
RI8
IK
AUDIO
LEVEL
FIGURE 5-1. INTEGRATED CIRCUIT
PHONO PRE-AMP SCHEMATIC
843 1368 1
CI6
25
Fl
1/1 AMP
C9 4:
1
C6
lOOpF
C5
io/:
C8
1
C3
-T 1 /2
CR2
UZ236
RI2
->WV
C4
1 /
2
HF
^R^V
1
4: CI8
1 /
5
-J-C2
T33 pF
J- CIO
1
5
PI
T
I
I 2
| TIP-3
I
rz
l -
1
r~
C12
. 3
1
1 — HL*
i
71
L t ____ I j
CI4
. 3
CI3
3
I 1
I TIP 29
I
I
_L ci
-r 75 pF
Ul
LF-356H
’ OR
£ r 7
> 1
< Rl I
5 3 6K
> R5 R6
S 5IK S9I K
LU 32 1-15
S RIO
1
£ Rl
S I6K
F ‘i
WHT ____
uz
BRN
4. INDUCTANCE IN H
3. CAPACITANCE IN F
2. RESISTANCE IN OHMS
I. RESISTORS ARE 1/2 WATT 5.
TtTTT
3
47 J, \
I7
025

SAFETY NOTI E
WARNING:
from the fail re of per-
LIABILITY LIMITATION
THE CURRENTS AND VOLTAGES IN THIS EQUIPMENT ARE DANGEROUS AND
UNDER CERTAIN CONDITIONS, COULD BE FATAL.
The man fact rer is specifically not liable for any damage or inj ry aris 
ing o t of fail re to follow the instr ctions in this Man al or fail re
to exercise d e care and ca tion d ring installation, operation, mainte 
nance and service of this eq ipment.
CAUTIONARY NOTICE
As with all electronic eq ipment, care sho ld be taken to avoid electrical
shock in all circ its where s bstantial c rrents or voltages may be pre 
sent, either thro gh design or short circ it. Ca tion sho ld also be ob 
served in lifting and hoisting eq ipment, especially regarding large str c 
t res, d ring installation.
THE INSTALLATION, OPERATION, MAINTENANCE AND SERVICING OF THIS EQUIPMENT
INVOLVES RISKS TO BOTH PERSONNEL AND EQUIPMENT, AND MUST BE PERFORMED ONLY
BY PROPERLY TRAINED AND EXPERIENCED PERSONNEL EXERCISING DUE CARE. PER 
SONNEL MUST FAMILIARIZE THEMSELVES WITH SAFETY REQUIREMENTS, SAFE HANDLING
AND OPERATING PRACTICE, AND RELATED FIRST-AID PROCEDURES (E.G., FOR ELEC 
TRICAL BURNS AND ELECTRICAL SHOCK) .
This man al is intended as general g idance for trained and q alified in 
stallation, operating, maintenance and service personnel who are familiar
with and aware of the dangers inherent to handling potentially hazardo s
electrical and/or electronic circ its. It is not intended to contain a
complete statement of all safety preca tions which sho ld be observed by
personnel in sing this or other electronic eq ipment.
HARRIS CORPORATION Broadcast Eq ipment Division.shall not be responsible
for inj ry or damage res lting from improper installation, operation, main 
tenance or servicing, or from the se of improperly trained or inexperienc 
ed personnel in the performance of s ch tasks, or
sons engaged in s ch tasks to exercise d e care.
The proced res o tlined in this Man al are based on the information avail 
able at the time of p blication and sho ld permit the specified se with
minim m risk. However, the man fact rer cannot ass me liability with re 
spect to technical application of the contents and shall, nder no circ m 
stances, be responsible for damage or inj ry (whether to person or proper 
ty) res lting from its se.
Always disconnect power before opening covers, doors, enclos res, gates,
panels or shields. Always se gro nding sticks and short o t high volt 
age points before servicing. Never make internal adj stments, perform
maintenance or service when alone or when tired.
Never remove, short-circ it or tamper with interlock switches on access
covers, doors, enclos res, gates, panels or shields. Keep away from live
circ its, know yo r eq ipment and don't take chances. Proper training
of experienced personnel and observing the above g idelines will help as 
s re safe and contin ed operation of this eq ipment.