Revox A76 Service Manual

3.
mono-stereo
switch "STEREO
AUTOMATIC"
(47)
de-
pressed
(thus
allowing
a
signal
to
reach the base
of
051
1
).
With all
three
conditions satisfied,
0512
becomes conductive
and
the
difference
channel
amplifier 0501
begins
to
operate.
With the switching
of
0512
the stereo
indicator "STEREO"
(output
EG
1
)
will also
receive
current.
For
multipath
indication
"MULTIPATH"
(42)
the multiplex
signal is being
fed to the monostable
trigger
0608/0607
and
signal
is
fed to the
monostable
trigger
0608/0607
and
receiving direct and reflected
signals,
will trigger that
cir-
cuit Into the
conductive mode,
thereby
causing the
light
bulb
"MULTIPATH" to become
Illuminated (
button "MUL-
TIPATH INDICATOR"
(50)
depressed).
3.a
Power supply
1
.076.130
(schematic
H)
1.076.140
The
power supply
consists
of two
electronically
regulated
sections
for
—23
V
and
+23 V.
Zener
diodes
stabilize the
supply
voltages
—6.2
V
and
+6.2 V
which
feed the
integrated
circuits
in the IF
amplifier auxiliary
circuits.
*
Modifications
MK II
*
Tuners
of
the
MK
II version have the
function
MULTIPATH
INDICATOR replaced by
the button
labeled STEREO
FIL-
TER
(
50
).
Therefore the
circuit
of the
indicator light
MULTIPATH
can no
longer
be
switched
off.
With
button STEREO
FILTER,
the signal to
noise ratio
of
week or distant stereo stations can be
improved.
This is
being achieved
by
reducing the bandwidth of the
38
kHz re-
sonant circuit
L501/C501
(
raising the
Q
by
disconnecting
the 8.2
kohm resistor). The
narrow
bandwidth
of
the
38
kHz
filter
results
in
a reduced stereo base; stereo crosstalk
drops
to
10 dB
at 1
kHz.
8

Revox A76 Specifications

General

Brand	Revox
Model	A76
Category	Tuner
Language	English