Denon DRA-25 - Measurement and Adjustment Procedures; Idle Current Adjustment; Measurement Setup Diagrams

wm DRA-25/25:L
METHOD OF ADJUSTMENTS
SP TERMINAL
TPt TPS
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TPH TPI2
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IDLE CURRENT ADJUSTMENT (Fig. 4)
1,
Keep
the unit
away
from
direct
wind
blown
by
an
air-conditioner
and
an
electric
fan,
and
keep
the
unit
under
normal
conditions. Adjust the range of ambient temperature to 15 — 30°C.
2. Set the following switches as follows:
@ POWER (power switch) to off
e@ VOLUME (VOLUME CONTROL) to 0()}
© SPEAKERS (speaker terminal) to no load (speakers disconnected)
3.
Remove
the
top
cover
and
connect
a
DC
digital
voltmeter
to
the
test
points
{between
the
positive
terminal
TP3
@
and
the negative terminal TP1 ©), and between the positive TP4 @ and the negative terminal TP2 (©).
4.
(1)
Connect
the
power
source
cord
to
an
AC
outlet
and
turn
on
the
power
switch;
read
the
measured
value
after
3
minutes
or
when
the
measured
value
is
within
a
tolerance
6
mV
~
90
mV
(DC),
adjust
the
idling
current
manually
as
follows,
(2)
When
the
voltmeter
reads
3mV
(DC)
or
less
under
the
condition
of
item
(1},
disconnect
the
39
ohm
from
re-
sistance
R517
and
R518.
co
® AC OUTLETS... For U.S.A., Canada and Asia models.
AC
outlets
are
used
for
connecting
amplifier
component
units,
such
as
tuner,
turntable,
tape
deck,
etc.
@ SWITCHED (Capacity: 100 W):
This
outlet
is
turned
on/off
when
main
power
switch
is
turned
on/off.
® UNSWITCHED (Total capacity: 250 W):
These outlets are always ON whether power switch is on or off.
e@
LINE
VOLTAGE
(Voitage
select
switch)
...
For
Asia
model
only.
*
The
desired
voltage
may
be
set
with
the
VOLTAGE
SELECTOR
KNOB
on
the
back
panel
using
a
screw
driver.
*
Do
not
twist
the
VOLTAGE
SELECTOR
KNOB
with
excessive
force.
It
may
be
damaged.
‘eo
*
if
the
voltage
select
switch
does
not
turn
smoothly,
see
a
qualified
serviceman.
=40 =
CONNECTION DIAGRAM OF MEASURING INSTRUMENTS
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OSCILLO| [ AC VOLT
SCOPE «|, METER
OSILLO
SCOPE
DISTORTION
METER
| AC VOLT |
METER
7
(9KHz
FILTER
DRA-25/25Lm
STEREO
MODULATOR
[ FM SSG 1
7
UY TUNING
4 gts METER |
TP TPI2
alll,
Ri28
TPil TPI2
cobs
LOOP
ANTENNA
AM_IF
SWEEP
GENERATOR
OUT