Specifications
SPECIAL
INSTRUCTIONS FOR OPTIONAL
120-240
VOLT POWER TRANSFORMERS
BLACK
BLACK
Dynakit
8CA-35 amplifiers
supplied
with optional power
transformer PB-028
can
be
wired for
use
with
either
120
or 240 volt, 50
or
60 cycle,
AC
power sources,
as
follows:
For r
20
Volt
Operation
1 ( ) Connect
the
black lead from
the
power transformer
to lug
#1
of AC
outlet
B.
2 ( )
Connect
the
black-and-white
lead
from
the
power
transformer to lug #
1 of AC
outlet
B
(8-3).
3 ( ) Connect
the
violet lead to lug A on
the
fuse hoide
4(
) Connect
the
violet-and-white lead to lug A on
the
fuse holder
(8-2).
VIOLET
a
WHITE
t
BLACK
aWHITE
.
VIOLET
240·yolt
•
VIOLET
aWHITE
I
BLACK
aWHilE
,
.
VIOLET
120·Yol'
The
bottom
plate
and
the cover
are
attached
at
the
same
time, by
setting
the
amplifier chassis
on
the
bottom plate,
which fits outside
the
main
chassis,
and
then
lowering
the
cover
onto
the
chassis.
The
chassis, bottom
plate
and
cove
are
fastened together by four
sheet
metal screws throu
the
sides of
the
cover.
This
should be done before
the
fron
panel
is installed.
Install
the
pilot
light
jewel
by
in-
serting
it
from
the
front of
the
panel,
gripping
the
jewel
spring
with pliers
to squeeze
it
open,
and
sliding
the
spring over
the
jewel
to
hold
it
in
place.
The
panel
should
then
be
placed
over
the
control shafts,
and
%"
nuts
placed
on
the
control
shaft
bushings
to
hold
the
panel
in
place.
Use
care
in
attaching
the
nuts
to avoid scratching
the finish of
the
panel.
The
cover
can
afterward
be removed,
if necessary,
without
removing
the
front panel.
All
the
knobs of
the
8CA-35 use small
set
screws to
secure
them
to
the
shafts. A small tip screwdriver is
required.
The
two large knobs go
on
the
selector switch
shaft
and
the
volume control shaft.
The
selector switch
shaft
has a flatted portion,
and
the
set
screw
in
the
knob
should be tightened
against
the
flat.
Then
when
the
knob
is
rotated
fully counter-clockwise,
the
index
mark
on
the
knob
should
point
to
"Tape
head".
The
balance control
and
volume control knobs should be
set
so
that
the
full counter-clockwise
point
corresponds to
7 o'clock
on
a clock face,
and
then
full clockwise
rotation
will correspond to 5 o'clock.
This
makes
the
index on
the
balance control
point
to 12 o'clock for nominally
balanced
operation. However,
either
of these knobs
can
be
installed
offset if desired so
that
the
12 o'clock position represents
average volume
and
balance
in
your
individual system.
The
bass control knob should be
set
so
that
full counter
clockwise
is
at
6 o'clock,
and
the
treble control knob
set
so
that
full clockwise is
at
6 o'clock.
The
12 o'clock position
will
then
be
the
electrically "flat"
setting
for each.
Tum
the
chassis upside down,
and
shake
it
vigorously to
dislodge
any
wire clippings
or
bits of
sol~er.
.
The
tubes
and
the
fuse should now be mstalled.;
the
pIC-
torial
diagram
shows
the
location of each tube.
IMPOR-
TANT:
When
inserting
the tubes
in
their
sockets for
the
first time,
the
socket should be
supported
from below
the
chassis to avoid
strain
on
the
circuit
board
because of
the
tight
fit of
new
sockets.
V-I
and
V-2
are
12AX7;ECC-83
tubes
and
are
installed
in
PC-ll.
V-3
and
V-4
are
7199
tubes; one of each is
installed
on each
PC-10
in
the
socket
closest
to
the
PC-ll
board. V-5, V-6, V-7
and
V-8
are
6BQ5;EL-84/7189 tubes,
and
they
go
in
the
remaining
PC-10 sockets.
Insert
the
pilot
lamp
in
its
socket.
The
four
rubber
feet should be
installed
in
the
corner
holes of
the
bottom plate.
To
mount
each foot,
insert
a
#6
machine screw
in
the
recessed
end
of
the
foot,
and
secure
it
with
a
#6
nut
on
the
inside of
the
bottom
plate.
PLACES
TO DOUBLE-CHECK
AFTER
WIRING
Be
sure
that
all
mounting
screws
and
nuts
are
tight.
Compare
the
wiring of each of
the
tube sockets
to
that
shown
in
the
pictorial diagram. All connections should be
securely soldered, with enough space between connections
to
the
tube
socket connecting lugs so
that
there is
no
chance
of
an
accidental short-circuit.
Compare
the
wiring to each lug of
the
filter capacitors
to
that
shown
in
the
pictorial
diagram. Check carefully to
see
that
all connections
have
been soldered,
and
that
excess
lead
length
has
not
caused
any
connection to short-circuit
to
the
chassis.
Examine
all
connections with
particular
care,
to
be sure
that
none
of
them
have solder blobs which
project
enough
to touch
the
bottom
plate
when
it
is installed. Check
the
terminal
strips
and
the
filter capacitors
in
particular.
Check
each
lug on
each
of
the
controls
on
the
front
panel, to be
sure
that
all of them
have
been soldered.
Check
the
twisted wires
at
the
ends
where
they
have been
soldered to see
that
the
insulation has
not
melted
to cause
a
shorted
condition.
This
will occur
if
too
much
heat
has
been
applied
when soldering these wires
and
they have been
twisted too tightly.
Pay
particular
attention
to
the
leads
going to
pins
#4
and
#5
of tube sockets V-5, V-6, V-7
and
V-B,
and
to lugs
#1,
#2,
#4
and
#5
of terminal
strip
T8-2.
The
wires to
the
selector switch
should
be positioned
as
shown below.
Note
particularly
the
twisted
pairs
to
lugs A3
and
A4,
and
to lugs B3
and
B4.
These
should
be close
to
the
front surface of
each
wafer.
16