Marantz SD1010 - Page 14

6.4
RECORDING
BIAS
CURRENT
ADJUSTMENT
SET UP
1.
Power
voltage:-
50
or
60
Hz
AC
voltage
rated
for
the
unit
to
be
used
in a
market
country.
2. TAPE SELECTOR switch:- NORMAL.
3. Load:- Measuring instrument input impedance.
PROCEDURES
. Connect the resistor 10 { between the Rec/Play
head and the lead wire (white).
. Set the TAPE SELECTOR switch to the NORMAL
position.
.
Set
up
the
tape
deck
in
the
recording
mode.
Cort-
nect
the
VT
VM
across
the
resistor
10
Q2.
.
Adjust
the
R316
(or
R317)
until
the
VTVM
reads
3.7
mV.
NOTES: 1. Proceed both for the right and left chan-
nels in the same manner.
2. For the tape deck equipped with the
TAPE SELECTOR switch, make certain
that the VTVM reads approximately
5.7 mV with it set to the CrO, position.
In the FeCr and METAL position, the
VTVM reads 4.5 mV and 7.5 mV, respec-
tively.
13
6.5 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 —23dB referenc-
ed as 0 dB.
. TAPE SELECTOR switch:- NORMAL.
. Output terminal:- LINE OUTPUT.
. Load:- Measuring instrument input impedance.
. Playback output level:- 43 mV (same as recorded
signal fevel).
. Test tape used:- TDK AC-212.
8. Tape Speed:- 1-7/8 IPS.
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 23dB with the
use of the attenuator. Record the 1 kHz and 12.5
kHz tones.
. Play the 1kHz, 23dB-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, O dB response,
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
AF OSC
TONE: 1 kHz,
—60 dB, —83 dB
/ATTENUATOR
RECORDED
LINE OUTPUT