dbx 363X - Threshold Calibration

4. Connect a
1 kHz
sine wave
at
1
volt
rms
to the
Channel
1
KEY INPUT
(
rear
panel
).
5.
Center
the
front
panel
knobs.
6.
Verify
that
both
green
OPEN
LED's are
on.
7.
Measure
the
AC noise at
the
Channel
1
and
2
outputs,
band-limited
to
20 kHz.
8.
Verify
that
the
noise
is less than
-85
dBv
(
44
micro
volts
rms
).
J.
Frequency
response
1.
Set all
front
panel
switches
to
the
OUT
position.
2.
Connect a
1 kHz
sine wave
at
I volt
rms
to the Channel
1
input.
3.
Set
the
THRESHOLD
control
to
the
center
position.
4.
Verify
that
the
green
OPEN
LED
is
on.
5.
Measure the
Channel
1
output
level
and
verify
that it is
1 volt rms
+/-
0.3
dB
(
see
step
D.
).
6. Measure the
output
level
at
20
Hz,
200
Hz, 5
kHz, and
20 kHz.
7.
Verify
that
the
output
level
for
all
of the
above
frequencies
is the
same
as
that
measured
in step
5
+/-
.5
dB.
8. Repeat
for
Channel
2.
K. Distortion
1. Set all front
panel
switches
to
the
OUT
position.
2.
Connect a
1
kHz
sine
wave
at
1
volt
rms to
the
Channel 1 input.
3.
Connect
a 590
ohm,
1 % resistor
from
the
Channel
1
output
to ground.
4. Set
the
THRESHOLD
control
to
the
center
positron.
5.
Verify
that
the
green
OPEN
LED
is
on.
6.
Measure
the
Total
Harmonic
Distortion
at
the
Channel
1
output
and
verify
that
it
is
less
than
.08
% .
7.
Repeat for
Channel
2.