Dual 1225 - Muting Switch; Record Drop; Shut-off and Change Cycle

Muting Switch
To prevent disturbing noise during the
change cycle and during automatic operation
of the tonearm the unit is fitted with a
muting switch. Control of the switch springs
for both channels is effected by the main
cam. With the unit in position of rest the
muting switch is opened.
199 173 132 A 193 180 223 202 212 245
Record Drop
Insert the appropriate spindle - AW 3 for
standard records (7 mm center hole) or AS 12
for 45 rpm records (38 mm center hole).
Record drop is initiated by rotation of the
main cam (193) whose cam surface guides the
cam rocker (A) and the change actuator stud
(173). The resultant downward movement ini-
tiates record drop via the changing spindle
or automatic spindle.
The record drop cam is located on the main
cam so that record drop can only take place
when the tonearm is over the tonearm rest,
that is to say, out of reach of the largest
possible records (12" diameter).
PTs, 7 Actuating "change" or "shut-off"
Shut - off and Change Cycle
The dog (M) of platter pinion (PR) and
shut-off
lever
(190)
actuate
both
the
chan-
ge
cycle
at
the
end
of
the
record
and
shut-
off
after
the
last
record
in
a
stack
is
pla-
yed.
At the end of a record the tonearm moves
towards the center at an accelerated rate
due to the increased pitch of the grooves.
This motion carries shut-off lever (190)
towards the dog by means of shut-off slide
(225). The eccentric dog pushes the shut-
off lever (190) back at each revolution as
long as the tonearm advance is only one nor-
mal record groove. (Fig. 17 a)
The run-out groove with its steeper pitch
moves the shut-off lever (190) against the
dog with greater force so that the shut-off
eae is picked up and moves with it. (Fig.
17° b
The
main
cam
(193)
is
thus
moved
out
of
its
neutral
position
into
engagement
with
the
pinion
of
the
platter.
(Fig.
17
c)
PR
M_
193
191
190
225
11