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Denon PMA-830 - Method of Adjustments

Denon PMA-830
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mu
PMA-S30
METHOD
OF
ADJUSTMENTS
DC
VOLTMETER
DC
VOLTMETER
L-CHANNEL
DS
{DIODE}
TRIZ0
(TRANSISTOR)
CONTACT
WITH
DIODE
AND
TRANSISTOR
VR5
VR3
(VR
6)
(VR
4)
R-CANNEEL
TR
13,D9
{TR
14,
D
10)
SYSTEM-A
=
210
TEST
POINT
SYSTEM-B
meee
PUX-020
POWER
AMP.
UNIT
SPEAKER
TERMINALS
DATA
FOR
ADJUSTMENTS
1.
Confirm
that
forming
has
been
effected
as
shown
in
the
drawing
for
D9
and
TR13,
and
D10
and
TR14,
respectively
of
the
L-
and
R-channels.
(PU
X-020)
2.
The
amplifier
switchs
should
be
set
as
follows:
(1)
SPEAKERS
switchs
to
“A”
system.
(2)
VOLUME
to
minimum
position.
(3)
DIRECT
COUPLE
to
OFF.
(4)
POWER
switch
to
OFF.
(5)
OPERATION
switch
to
“B”
position.
(6)
Confirm
that
a
U-sharped
short
pin
is
inserted
between
the
PRE-OUT
and
MAIN-IN
terminals.
3.
{1}
Connect
a
D.C.
voltmeter
to
the
SYSTEM-A
terminal.
(2)
Connect
a
D.C.
voltmeter
to
the
test
points
of
both
the
L-
and
R-channels
of
the
PUX-020.
Special
attention
should
be
paid
here
with
regard
to
the
polarities
of
the
test
point
voltages:
make
sure
that
16
is
—
and
17
+
for
the
L-chan-
nel,
and
that
35
is
—
and
36
+
for
the
R-channel.
4.(1)
After
setting
the
voltage
regulator
to
0
V,
switch
the
amplifier’'s
power
switch
on.
(2)
While
ovserving
the
indication
of
the
D.C.
voltmeter,
raise
the
power
supply
voltage
from
zero
to
the
rated
voltage
by
using
the
voltage
regulator,
and
carry
out
the
preliminary
adjustments
of
(3)
and
(4)
in
a
swift
manner.
(3)
By
adjusting
VR1
(L-channel)
and
VR2
(R-channel)
of
the
PUX-020,
regulate
the
speaker
terminal
voltage
to
the
ih
range
of
OV
+10
mV.
(4k
By
adjusting
VR5
(L-channel)
and
VR6
(R-channel)
of
the
PUX-020,
regulate
the
rest
point
voltages
to
12
mV
(10
to
14
mV)
[Collector
current
to
26
mA
(22
to
30
mA)].
5.
(1)
On
completion
of
the
preliminary
adjustments
described
above,
carry
out
the
main
adjustments
described
below.
(2)
“
By
adjusting
VR1
(L-channel)
and
VR2
(R-channel),
adjust
the
speaker
terminal
voltage
again
so
that
it
will
be
in
the
range
of
OV
+10
mV.
|
(3)
“Adjust
VR5
(L-channel)
and
VR6
(R-channel)
again,
regulating
the
test
point
voltage
to
17
mV_+1
mV
(Collector
current
to
26
mA
+2
mA).
(4)
With
the
above
adjustments,
the
speaker
terminal
voltage
adjustment
and
idling
current
adjustment
for
B-class
operations
have
been
completed.
6.
(1)
Change
over
the
OPERATION
switch
to
Class
A.
(2)
By
adjusting
VR3
(L-channel)
and
VR4
(R-channel)
of
the
PUX-020,
carry
out
adjustment
of
the
test
point
voltage,
regulating
it
to
470
mV
+10
mV
(Collector
current
to
1
A
+0.02
A).
7.
(1)
Switch
over
the
OPERATION
switch
and
effect
aging
for
10
minutes.
(2)
By
adjusting
VR3
(L-channel)
and
VR4
(R-channel)
of
the
PUX-020,
regulate
the
test
point
voltage
to
500
mV__
f.
+5
mV
(Collector
current
to
1.06
A
+0.01
A).
With
the
above
operations,
idling
current
adjustment
for
A-class.
operations
has
been
completed.
CAUTION
1.
Never
switch
off
power
until
the
idling
current
adjustments
for
Class-A
operations
have
been
completed.
2.
Special
attention
should
be
paid
in
handling
the
variable
resistors
used
for
adjustments,
i.e.,
VR3
and
VR4,
and
VR5
and
VR6,
as
they
can
be
easily
mistaken
for
one
another.
lf
by
mistake,
VR5,
or
VR6
has
been
used
for
the
idling
current
adjustment
for
A-class
operations,
readjustment
must
be
carried
out
(after
confirming
that
the
radiator
of
the
power
amplifier
has
cooled
down)
for
B-class
operations,
since
the
mistake
will
cause
a
deviation
in
the
adjustment
for
B-class
operations.
On
completion
of
this,
carry
out
adjustments
for
A-class
operations
again.
3.
The
adjustment
of
6.
(2)’’
should
be
effected
after
about
10
seconds
have
passed
following
switch-on
of
the
OPERA-
TION
switch.
ny
se

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