Crown PSA-2 - Page 85

Input Signal
Type
of
Test/
Adjustment
Characteristics
D. IKHz sine wave;
2V; | ohm load
E. 20KHz sine wave;
2V; 8 ohm load
F. 10KHz sq. wave;
2V; 8 ohm load
Comments
&
D. 30V minimum should be obtainable before clip.
E. 44V minimum should be obtainable before clip
F.
50V
minimum
should
be
obtainable
before
clip;
signal
should
be
a
good
square
wave
with
no
abberations
(Fig.
7.22).
Fig.
7.22
Correct
Square
Wave
Output
Waveform
15.
Thermal
20K
Hz
sine
wave,
variable
input;
|
ohm
load (output at 21V)
16. Mono IKHz sine wave; 2V;
no load
On
each
output
module,
observe
the
voltage
(actually
temperature)
on
test
pin
“Q”.
Voltage
should
drop
to
approximately
3.0V-3.2V
as
signal
reduces
in
amplitude
Using
only
channel
|,
apply
input
signal
with
mono/stereo
switch
in
MONO
position.
Observe
the
output
signal
simultaneously
of
both
red
or
“hot”
terminals
of
both
channels.
They
should
be
180°
out
of
phase
(see
Fig.
7.23)
fs
Fig. 7.23 Mono Output Waveform
17. 1M Distortion 60Hz/7KHz signal
summed in a 4:1 ratio
(See Fig. 7.24 for hook-
up)
18. Signal/ Noise None - (See Fig.7.25
for hook-up)
19. Quiescent Power None
7-17
Using Crown IMA, readings should be from 0 to -25dB,
less than .004%, all other, less than .01%.
With
a
sensitive
ACVM,
output
signal
should
be
at
least
110dB
below
rated
output
power.
Also,
use
a
20Hz-
20K
Hz
bandpass
filter
ahead
of
the
voltmeter.
Should be less than 90W.
my) (