Sony TA-2000F - Page 6

Function
switches. Note that the TAPE-
TO-TAPE positions in the FUNC-
TION-1 switch are provided for
tape duplicating as noted in
Table 1-2.
TABLE 1-2.
FUNCTION-1 Tape Tape
Position Recorder-1 Recorder-2
TAPE-TO- ‘
TARE : as ieee -
TAPE 21 eae
Stage/Control Function
MIC Amplifier /PHONO-2 Equalizer Amplifier Section
MIC Amplifier The MIC amplifier consists of
Q301, Q302 two pairs of FET-NPN amph-
Q303, Q304 fiers. They amplify the signals
provided by the microphones to
the level required at the input
of the tone-amplifier.
An FET has high input imped-
ance and generates less noise
than conventional silicon tran-
sistors. Therefore, FET’s are
employed in the low-level am-
plifiers. Note the high-voltage
Stage/Control
TAPE 2-1
Bias circuit
MIC amplifier
Q303, Q304
MIC LEVEL
control VR6
mixing switch
$15
PHONO-2
Equalizer
Amplifier
Q305, Q306
Q307, Q308
Q309
Function switch
transistor Q302 (Q304) employ-
ed in the second-stage amplifier.
This eliminates distortion due
to strong input signal causing
saturation in the low-level am-
plifier.
Dc bias voltage for Q301 is
determined by the current flow
in the source resistor R306, and
the dc negative feedback voltage
applied to the gate of Q301
from the emitter circuit of Q302
through R304 and R302.
Q303 and Q304’s operation is
the same as described in Q302
and Q303. Note that the last
stage (Q304) is a conventional
transistor since the high-level
input signal is sufficiently at-
tenuated by means of MIC
LEVEL control VR6 so as not
to saturate Q303 and Q304.
The MIC LEVEL control and
mixing switch S15 are mecha-
nically connected to perform
the mixing operation.
Same as described in PHONO-!
equalizer amplifier section ex-
cept for reference numbers.
Note that the output of this
amplifier can be controlled by
means of VR1, LEVEL ADJUST.
Input signals applied to the
TAPE-1, TUNER, AUX-1, AUX-
2 input terminals are controlled
respectively by means of VRS,
VR2, VR3 and VR4.
All input signals are routed to
FUNCTION-1 or FUNCTION-2
REC OUT
Buffer Amp
Q01, Q51
MONITOR
switch S3
MODE switch
BALANCE
control VR7
All input signals are equalized or
controlled by means of equalizer
or LEVEL ADJUST resistors,
and then fed to the FUNCTION
switches.
The signals for REC OUT are ex-
tracted from the signal path be-
tween the FUNCTION switches
and MODE switch, and then fed
to each set of REC OUT termi-
nals through buffer amplifier
(emitter follower) QO1. QOl
eliminates interaction between
the tape recorder and the
TA-2000F’s signal path. Note
that QOl’s output is routed
through muting relay REL-1.
In the TAPE-1! position, input
signals connected to either the
TAPE-1 terminal or REC/PB
connector is selected. In the
TAPE-2 position, the input pro-
gram connected to the TAPE-2
terminal is selected. In the
SOURCE position, all other pro-
gram sources are selected.
Selects the desired mode of
operation. This switch may also
be used for test purposes. The
relation between the positions
of the MODE switch and out-
puts of the set are summarized
in Table 1-3.
Input signal is routed to the
BALANCE control through
MODE switch $4. This is done
to optimize stereo reproduction.
To eliminate insertion loss at