Marantz SD1010 - Page 6

3.2 PLAYBACK TIME CONSTANT
The reason why the playback equalizer time constant is
switched is so that any type of tape can have optimum
performance at any of the two available tape speeds.
* For SD3020 & SD1020
TAPE SPEED TAPE SELECTOR TIME CONSTANT
(IPS) POSITION {usec)
1-7/8 NORMAL 120
1-7/8 SPECIAL/FeCr/METAL 70
3-3/4 NORMAL 70
3-3/4 SPECIAL/FeCr/METAL 35
The
time
constant
is
selected
between
35,
70
and
120
us
using
a
transistor
switching
circuit.
2 $303 $304
] |e | les, | Jette
SS
TO REC EO
TIME CONSTANT (usec)
120
70
3.3
RECORDING
COMPENSATION
The
method
of
recording
compensation
is
the
same
as
that
used
in
our
existing
units
where
the
amount
of
feed-
back
in
the
recording
amplifier
(0115)
is
varied.
TAPE SPEED} TAPE SELECTOR
(IPS) POSITION COMPENSATION
1-7/8 NORMAL Peaking by L102, R164 and
C139 only
1-7/8 SPECIAL Rec, CuR, R155, Peaking
(CrO2) R166, C140, L102
Mid range R156, C136
1-7/8 Fe-Cr Peaking R168, C141(L102)
Mid range R159, C137
1-7/8 METAL Rec, CuR, R161, Peaking
R170, C142(L102)
Mid range R162, C138
*3-3/4 NORMAL Peaking R415, C405, L102
Mid range R404, C409
*3-3/4 SPECIAL Rec, CuR, R406, Peaking
(CrO2) R417, C406, LiO2
*3-3/4 Fe-Cr Peaking R419, C407, L102
Mid range R410, C403
*3-3/4 METAL Rec, CuR, R412, Peaking
R421, C408, LIO2 |
* and bracket ( —) means without $D1010.
* For SD3020 & SD1020
8 7654321
1 3-3/4METAL 2 1-7/BMETAL 3 3-3/4 FeC
4 1-7/8 FeCr 5 3-3/4SPECIAL 6 1-7/8 SPECEAL
7 3-3/4 NORMAL 8 1-3/8 NORMAL
* For $D1010
1 METAL 2 SPECIAL 3 NORMAL 4 feCr
3.4 PEAK LED METER CIRCUIT (SD3020 only)
If the signal amplified and rectified by Q127 through
Q130 in the figure is connected to the IC ha sed in the
Peak Meter, then it is compared with the refu- ence volt-
age. The different voltage illuminates the light.
Q129
Q130
12V
DOLBY
Vee
4.26V
REFERENCE
VOLTAGE