Marantz 1090 - 7. PERFORMANCE VERIFICATION; Test Equipment for Performance Verification; Preliminary Test Procedures

6.
TEST
EQUIPMENT
REQUIRED
FOR
SERVICING
Line
Switch
OFF
Variable-line
switch
Variable
Table
1
lists
the
test
equipment
required
for
servicing
the
Wattmeter
Switch
ON
Mode!i
1090
Stereo
Console
Amplifier.
The
wattmeter,
Variable
Autotransformer
0
V
(fully
CCW)
AC
voltmeter,
and
variable
autotransformer
may
be
assem-
Load
8 ohms
(0.5
mfd
—
OFF)
bled
as
a
test
fixture
as
shown
schematically
in
Figure.
Audio
Generator
1kHz
The
load
resistors
and
AC
ammeter
may
be
assembled
into
Output
5
V
range
a
second
test
fixture
as
shown
in
Figure
2.
Gain
Minimum
AC
VTVM
30
V
range
7. PERFORMANCE VERIFICATION
2. Make sure that connections between the resistive
TEST PROCEDURE load and the system terminals of the Model 1090
have negligible resistance when compared with the
A. TEST EQUIPMENT resistance of the load itself. Appreciable resistance
Refer to Table1 for required test equipment. in wiring adds to the total load, resulting in inaccu-
rate measurements of output power.
B. PRELIMINARY PROCEDURES xe
3. Connect amplifier output to load and connect AC
1. Make the test setup shown in Figure 1 with the cord to line power. Connect shorting plugs to the
instrument controls set in the following positions: Phono input jacks of the Model 1090.
Table 1. Test Equipment Required for Servicing
Item Manufacturer and Model No. l Use
\ ss S = eee oer
Distortion Analyzer Distortion measurements
Audio Oscillator Sound Technology Model 1700B Sinewave and squarewave signal source
AC VTVM voltage measurements (AC}
. Tektronix Model T932 Waveform analysis and trouble shooting and
Oscilloscope i F
Philips Model 3232 ASO alignment
Circuit Tester a ad —- : Trouble shooting
‘ Fluke Model 8000 “Digital” Simpson
M Voltage measurements (DC
Oey Model 313, Triplet Model 801 pe
AC Wattmeter lr. Simpson Model 1379 _ Monitors primary power to amplifier
{ pee es ppeerllen. ee . 4
Moni ifi ircui
ReReameter Conmercial Graded S10-A) OGiEOTs armel: ier output under short circuit
condition
= ae 1 nee ate St Sete os ast a
Moni ; :
Line Voltmeter Simpson Model 1359 SPuOlS Potential OR PU Maly BOWEr TO
amplifier
ae
|
shan
|
Superior Electronic Co., . . fat
Variable Autotransformer Pee Model 116B-10A Adjusts level of primary power to amplifier
l . > Use phono plug with 600 ohm i Shorts amplifier input to eliminate noise
Shorting Plug . :
across center pin and shell pickup
Output Load Conaiarsial Grade Provides 8-ohm load for amplifier output
(8 ohms, +0.5% 100 W) termination
t Load Provides 4-ohm load for amplifier output
Commercial Grade
(4 ohms, 0.5% 100 W) termination
Output Load Capacitor Mytar Provides capacitive load for instability checks
(0.5 mfd)
AC ve Goal Bax Optional Item. Rabricate in Monitors and controls primary power for
accordance with Figure 1 amplifier
upline Outaue bakBox Optional Item. Fabricate in Provides various amplifier loads and can
accordance with Figure 2 monitor shorted output