Dual 601 - Pitch Control

Fig. 9
104
12 10
127
107
109
108
125
Defect
Nominal
speed is
at
the edge
of the con—
trol
range
of the
pitch
control.
Platter does not
run
after the line
volta—
ge cord of
the unit
has
been
plugged in —
to
the
receptacle and
the master
operating
switch
moved to
"start".
Platter does
not come
up to its
required
speed.
Fig.
10
111
Cause
Position of
toothed
belt pulley inac—
curate.
a) Power supply to
motor interrupted
b) Drive pulley
slackened
a) Drive pulley is
not correct for
local line fre—
quency
b) Slippage between
flat belt and
drive pulley or
between flat belt
and flywheel ro—
tor
Excessive fric—
tion in motor
bearing or fly—
wheel rotor
bear—
ing assembly
(161)
)
Pitch
Cont rol
The unit
has a
separately
adjustable pitch
control by
which the
two
standard speeds
33
1/3
and 45 rpm can be
varied by ap—
proximately 6
% (1
semitone).
By
turning the
fine speed
adjustment
knob
(10)
the toothed
belt
(Fig. 7)
thus moving
the
counter
bearing (111)
upwards
or down —
werde. The
taper bush
of the
drive pulley
(129) is
designed to
vary the
diameter
of
the drive
pulley
(129) thus
varying the
no—
minal speed
within the
tolerance of + 3
%.
Remedy
By turning fine speed
adjustment knob (10)
move stop disk (109) to its center position
(The dog of the stop disk should face the
center of the drive pulley). Using adjusting
nut (108) adjust for nominal speed. The
nominal speed is increased by turning
the
adjusting nut (108) clockwise and decreased
by turning the set screw counterclockwise.
a) Check connection at
switch plate and
power supply plug.
b)
Retighten drive
pulley
a)
Renew drive
pulley
b) Clean
friction surfaces of flat
belt,
drive
pulley and flywheel rotor. Renew
flat belt if
neccessary. Once the fly—
wheel rotor has been
cleaned do not
touch
it with
your fingers.
c)
Clean and
oil bearings
Ddect
Pick
—up head not
parallel to platter.
Cause
The pick —up
head has been
moved out of po—
sition on the tonearm
tube during transport.
Remedy
Remove platter. Using
a screwdriver slacken
screw on
the pick —up head through the hole
provided for this
purpose in the chassis
plate. After
aligning the pick —up head re—
tighten screw (Fig. 10).
6