Dual 621 - Adjustment Point

Fig.
10
ibr
6
44‘.
Adjusting the tonearm bearing
First balance tonearm exactly. Both bearings must have slight,
just perceptible
play. The horizontal tonearm bearing is
correctly
adjusted when at anti-skating settings "0.5" and
being touched lt
slides in
without resistance. The vertical tonearm bearing is
correctly adjusted
when
lt
swings in after being touched. The
play of the horizontal tonearm bearing
should be adjusted with
threaded pin (33) and that of the vertical tonearm bearing with
threaded
pin (56).
A nt i-skat i ng Device
To compensate for skating force use
the knurled ring 166). The
asymmetric cam plate (213)
displaces the skating lever (211)
from
the tonearm pivoting
point. The anti-skating force is
trans-
mitted to the
segment (208) and to the
tonearm (48) by
tension
spring (209).
Optimum adjustment is
carried out at the factorys
for styli
having
a tip radius
of 15 /Im (conical), 5/6
and
18/22 /I m (ellipti-
cal), and
CD 4-cartridges.
Any alteration
can only be carried
out with the aid of a
Dual -
Skate -0 -Meter and a test
record and should only be done
by an
authorized service station.
Recheck
es follows:
Balance tonearm
(48)
correctly. Set knurled ring
(66) to 0. The
tonearm should remain at any
desired point within its
turning
range.
The hole of the skating
lever (211) should be in
alignment
with the
center line of the
tonearm. Adjustment is made by
the
eccentric
pulley (E) which is accessible through the
hole in the
Installation plate (23)
between the knurled ring
(68) and the
tonearm.
Then set knurled
ring (66) to "0.5". The tonearm
should now
smoothly rotate from the platter center to its rest (71).
Cue Control
By moving
the lever
(190) forward (
•
) lift
cam (192) rotates.
The slide bar
(141) transmits the
lifting movement to
the lift pin
(206), that raises the tonearm. As a result, the
cue control per -
m its raise up the tonearm at any desired point.
The lever (190) is released by
moving the cue control lever rear
wards
(X l.
As a result of the action of
compression
spring
(205)
the lift
pin (206) is brought back to its normal
position and the
tonearm loweres slowly. Lowering of the tonearm is damped by
silicone oh l in the lift
tube.
Adjustment
Point
The
lift
can be
varied by
turning
the
sleeve (45).
The
distance
between
the record
and the
needle
should be
5
-7 mm.
Replacement of Cue Control
Platts
Replace cue control
plate (207) as follows:
1.
Clamp unit in
the repair jig.
and lock
tonearm. Turn unit
in
head position.
2. Remove safety washer (184).
Lift
off main lever
(183)
and
bearing support
(182).
3.
Remove safety
washer (144). Lift
off positioning
bar (141)
and rotary bearing
(143) and turn towards
motor (149).
4.
Remove both
machine screws
(204), remove lift
plate compl.
(207).
For installation
proceed in the reverse order.
Fig.
11
Fig. 12