Sony SEQ-555ES - Page 18

B
Q Insulator washer
SS, P| Neo
SECTION 4
ADJUSTMENTS
Frequency Response Adjustment:
Be sure to perform the following adjustment when
replacing the microphone.
(This adjustment is performed to flatten the frequen-
cy response by correcting the 125Hz and 16kHz
level difference relative to 4kHz.)
Connection Diagram:
low frequency oscillator
more than
1001 /6.3V
MIC jack MIC amp output
test pin
Procedure:
The set may be in any state.
1) Apply a 4Hz signal to the MIC jack from the
oscillator, and adjust input level so that output is
—10dBs.
2) Set frequency to 16kHz, and adjust RV201 to
correct MIC data value only.
3) Set frequency to 4kHz and adjust input so that
output is —10dBs.
4) Set frequency to 125Hz, and adjust RV202 to
correct MIC data value only.
MIC data is as follows.
oe ee eee
’ ' '
+10dB OdB +5dB
The level difference relative to 4kHz for each
frequency is to be corrected.
In this example, 125Hz is corrected +10dB
relative to 4kHz.
16kHz is corrected +5dB relative to 4kHz.
(When the adjustment is not exact with the
adjustment resistors, get it as close as possible.)
frequency response adjustment
test pin
SEQ-555ES
SEQ-555ES
RV201 RV202