Marantz SD9000 - Page 35

8. Recording Equalizer Adjustment
SETUP
1. Power voltage:— 50 Hz/60 Hz AC voltage rated for
the unitto be used in a market country.
2. Input level:— —20 dB lower than —60 GB.
3. Tape selector switch: - NORMAL.
4. Output terminal:— Lch. J414 (Hot), J444 (GND)
R ch. J435 (Hot), J445 (GND)
PROCEDURES
1. Stop the recording bias current oscillator. Cutting
out the bias circuit.
2. Set up the unit to the normal recording state.
Reduce the input level by 20 dB.
3. Set the Tape selector switch to the Normal posi-
tion. Set the audio-frequency osocillator to
15 kHz. Connect the VTVM L ch. J414 (Hot),
J444 (GND), R ch. J435 (Hot), J445 (GND).
Adjust L102 and L202 for maximum VTVM read.
Tape speed selector switch — (Standard speed).
4. In turn, set the Tape selector switch to NORMAL
position. Set the audio-frequency oscillator to
22 kHz. Connect the VTVM L ch. J414 (Hot,)
J444 (GND), R ch. J435 (Hot), J445 (GND).
Adjust L103 and L203 for maximum VTVM read.
Tape speed selector switch — (High speed).
5. After adjustment, release the recording bias.
CAUTION
The adjusting rod should be non-metalic.
9. Record-Playback Frequency Response Adjustment
SETUP
. Power voltage:— 50 Hz/60 Hz AC voltage rated for
the unit to be used in a market country.
. Tape selector switch: —- NORMAL.
Tape speed selector switch: — STANDARD &
HIGH.
. Input signalt:— 1 kHz, —60 dB with ~—23 dB refer-
enced as 0 dB.
. Output terminal:— Line out.
. Load: Measuring instrument input impedance.
. Playback output level:— Same as the recorded
signal level.
. Blank tape used:— AC-211, AC-511, CS-30 &
AC-701.
PROCEDURES
. Connect the input signal to the MIC terminal. Set
up the unit to the normal recording state.
. In turn, reduce the input level by —23 dB (25 dB
down from Dolby Level) with the use of the
attenuator. Record the 1 kHz and 10 kHz tones.
. Play the 1 kHz 23 dB down recorded tone back as
O dB. Adjust the recording bias current until the
10 kHz response is within +0.5 dB as referenced to
the 1 kHz, 0 dB response.
36
. Follow similar sequence for the other Tape Selec-
tor switch positions (Fe-Cr, CrO2, and Metal) and
adjust the bias current so the frequency response
falls within the specified range.
. When the tape speed is High, adjust Rec. EQ for all
the Tape Selector switch positions to provide res-
ponse within specifications.
. Proceed both for the right and left channels in the
same manner.
. If the recording current is recorded reduced in the
above adjustment, be sure to measure the distor-
tion.
Mode: Record
TONE: 1 kHz,
—60 dB
ATTENUATOR
—85 dB
RECORDED
PORTION
LINE OUTPUT
Record/Play Back Frequency Response Adjustment
Standard
Tape EQ Bias
Normal O @
Fe Cr fix
©
CrO2 . fix ©
©
Metal fix
1. Columns marked O, ®, and © include adjusting
arrangement.
2. O Concerning fixed EQ columns, only Normal
Tape is marked adjustable but if readjusted for
Normal Tape, the other tape positions are also
affected.
. ® includes trimming controls for both L ch. and
R ch. (2).
© includes a trimming contro! common for L ch.
and R ch. (1).