Marantz SD4000 - Record-Playback Frequency Response

6.9 RECORD-PLAYBACK FREQUENCY RESPONSE
ADJUSTMENT
SET UP
1.
Power voltage:- 50 or 60 Hz AC voltage rated for
the unit to be used in a market country.
. Input signal:- 1 kHz, —60 dB with —20 dB referenc-
ed as O dB.
. TAPE SELECTOR switch:-METAL.
. Output terminal:- LINE OUTPUT.
. Load:- Measuring instrument input impedance.
. Playback output level:- 43 mV (same as recorded
signal level).
. Test tape used:-METAL C-46.
. Tape Speed:- 1-7/8 IPS (4.75 cm/sec).
PROCEDURES
.
Connect
the
input
signal
to
the
MIC
terminal.
Set
up the tape deck to the normal recording state.
. In turn, reduce the input level by 20 dB with the
use of the attenuator. Record the 1 kHz and 12.5
kHz tones.
. Play the 1kHz, 20dB-down recorded tone back
as
OdB.
Adjust
the
recording
bias
current
until
the
12.5
kHz
response
is
within
+1
dB
as
referenced
to
the
1
kHz,
0
dB
response
by
adjusting
R912
and
R913.
. Adjust the recording bias current by using test tapes
AC701,
AC-511
and
CS-30
in
the
same
manner.
AC701_
:
R305
(Metal)
AC-511 : R306 (CrO./Special)
CS-30 : R307 (FeCr)
NOTES:
1.
Proceed
both
for
the
right
and
left
chan-
nels in the same manner.
2. If the recording bias current is reduced
in the above adjustment, be sure to
measure the distortion.
Mode: Record
! PORTION
TONE: 1 kHz,
—60 dB, —80 dB
RECORDED
LINE OUTPUT
16