Dual 601 - Tonearm and Tonearm Bearing; Adjustment of Tonearm Bearing

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Tonearm
and
Tonearm Bearing
The Dual
601 has a feather—light, extremely
torsion—resistant all—metal tonearm which is
suspended in a gimbal. Suspension is
by
means of 4 hardened and precision
polished
steel
points which rest in precision bell
bearings. Tonearm bearing friction is thus
reduced
to a minimum.
Bearing friction vertical g
0.007
Bearing friction
horizontal g 0.015
related
to stylus point
As a
result,
lt
ensures extremely
favourable
pick —up conditions. The
pick —up head is re—
movable. Before adjusting the
pick —up force
to suit
the built—in pick —up
cartridge the
tonearm is
balanced with the scale set to 0.
Coarse adjustment is
carried out by moving
the counterweight (52) with stem
(51), the
subsequent fine adjustment by turning the
weight.
The balance weight is designed so that pick —
up
cartridges with a deadweight of 2 — 10 g
can be balanced.
For the absorption of
Vi-
bration
and rapid small shocks, the
counter—
weight is
flexibly connected to its
threaded
stem and arrested
to prevent
unintentional
rotation. The pick —up head is
suitable for
accommodating all pick —up cartridges
whose
type of mounting
conforms With the interna—
tional standard 1/2
inch mounting and whose
deadweight does not
exceed 10 g. The treck—
ing force is
adjusted by
turning the gradu—
ated spring housing (59) and
thus tensioning
or releasing
the coil spring mounted inside.
To change the
tonearm complete
with tonearm
suspension we
recommend preceeding
as fol—
lows:
1.
Secure
unit in repair jig
and arrest
tonearm.
2. Move unit
into head position and
unsol—
der
tonearm leads.
3. Remove main
lever (154) and
compression
spring
(180).
4. Disengage tension
spring (260), undo
washer (268) and remove
skating lever
(265). Be
careful with
compression spring
(267) as lt may drop out.
5.
After removing washer
(264) and sliding
washer (263) detach
shut—off bar
(262)
from segment (258).
6. Undo hexa9on
nut (259) and pull
off seg—
ment
(258).
7. Remove hexagon nut
(217) and washer
(67),
then with draw
tonearm complete with
sus—
pension.
When
inserting the tonearm complete
with
suspension proceed in reverse order.
To remove the tonearm from the bearing race
the tracking force scale should first be
set
to zero
position after unsoldering the
tonearm
leads. Unscrew locknut (60) with
grub screw (51) and mounting screw
(65).
Carefully
withdraw tonearm from the bearing
race. For adjusting the tonearm head, a
hole is provided in the chassis to make
this possible without first removing the
tonearm.
Adjustmentc4lbnearniEleahng
Both bearings must
haue slight, just per—
ceptible
play. Adjustment of the
vertical
bearing should only be carried out by
means
of the left mounting screw
(grub screw 61),
that of the horizontal bearing by means
of
grub screw (36). The
horizontal tonearm
bearing is correctly adjusted when at
antiskating setting "0.5" (tonearm pre—
viously balanced exactly) the tonearm
slides in without resistance.
Fig. 11 Tonearm
bearing assembly
66
60
61
37
211
44
258
Fig. 12 Tonearm bearing assembly
(view
from
underneath)
35
36
54
65
59
52
55
62
265
259
256
262
154
149
150