Dual 1225 - Tonearm and Tonearm Suspension; Replacing the Complete Tonearm and Bearing Assembly; Replacement of Tonearm

Tonearm and Tonearm Suspension
The tonearm of the Dual 1224 and 1225 is
counter balanced and pivot mounted verti-
cally and horizontally. This provides ex-
tremely favourable tracking characteristics.
The tonearm head is removable. To aid in
replacing or adjusting the tonearm head a
hole is provided in the chassis to facili-
tate adjustment of the tonearm head witheut
first removing the tonearm. Before setting
the correct stylus force for the cartridge
which has been installed the tonearm should
be balanced with the stylus force setting
at zero. It is recommended that balancing
should be carried out in the direct vici-
nity of the tonearm rest. This is carried
out by rotating the counterweight.
Fig. 7 Tonearm bearing assembly
Fig. 8 Tonearm bearing assembly
(view from underneath)
68
58
55
241
245
212
225
223
The counterweight is designed so that it
can balance cartridges weighing 1 -— 10 gq.
For shock absorption (absorption of brief
shocks) the counterweight is flexibly moun-
ted on the tonearm and secured to prevent
unintentaional rotation. The tonearm head
is designed to accept all cartridges with
internationally standard 1/2" mounting cen-
ters and weighing not more than 10 gq. Sty-
lus force is set by rotating the graduated
spring housing (ses and thus tensioning or
slackening the coil spring contained the-
rein. The scale is calibrated for an ad-
justment range of O - 5 p, permitting ac-
curate setting within that range in 0.5 p
steps.
Replacing the Complete Tonearm
and Bearing Assembly
To replace the complete tonearm and bearing
assembly we recommend proceeding as follous:
1. Tighten unit in repair jig, set stylus
force scale to zero and lock the tonearm
in position
2. Turn unit upside down, remove retainer
spring (188) and: unsolder tonearm leads
3. Remove main lever (223), disengage spring
(256)
4. Remove lock washer (227) and skating disc
(226), remove shut-off slide (225) from
eccentric pin on segment, ensure ball
(224) does not drop out
5. Slacken hexagon nuts (244), remove seg-
ment (245), then remove tonearm, ensu-
ring that bearing pivot (39) and compres-
sion spring (40) do not drop out.
Tonearm complete with bearing frame assem-
bly should be refitted in reverse order. The
unit is in normal position. Insert tonearm
complete with bearing frame assembly and
lock in rest. With tonearm held in place
turn unit upside down. Place segment (245)
in position and fit hexagon nuts.
Replacement of Tonearm
To remove the tonearm from the bearing fra-
me unsolder the tonearm leads and set the
tonearm tracking force scale to zero. Uns-~
creu locknut (65) with setscrew (64) and
bearing screw (68) (left-hand thread). Care-
fully remove tonearm from bearing frame.