Kuzma STOGI REF 90630 - Manual (Page 10)

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4.3. Adjustment of VTA:
VTA describes the angle between the record surface and the stylus. This angle
changes as the height of the tonearm is altered. The standard angle is 15° but
cartridge manufacturers work with degrees of anything between 10°- 30° so only by
listening tests can one ascertain the correct angle for your particular cartridge. The
VTA also varies according to the tracking force and thickness of records. An increase
in tracking force is equivalent to lowering the tonearm and vice-versa.
For your information to change the angle by 1° means a change in height of
approximately 3mm on the pillar. Some styluses need more precise adjustment of
VTA than others.
Starting position is that the central axis of the tube is parallel to record surface.
With felt pen mark the position where the pillar meets the base as a point of
reference.
Use a good recording, preferably acoustic instruments and listen.
If the tonearm is too low the sound has a tendency to have an overblown base and
the stereo picture is imprecise.
If the tonearm is too high the sound tends to be too bright, ie. too aggressive,
especially on acoustic strings.
Try moving the tonearm up and down in 2mm steps to judge where the arm
sounds most balanced with a more precise stereo picture.
Fine adjustments can be made in the range of 0.5mm.
Now fix height firmly.
4.4. Adjustment of azimuth:
Azimuth describes the angle between the record surface and the stylus, viewed from
the front of the cartridge. This should be 90° and can be checked by observing if the
cartridge body is square with its mirror image on the blank part of a record or by
putting a mirror under the stylus (taking care that the stylus does not slide). If using a
mirror ensure that it is absolutely flat.
4.4.1. Rough Azimuth adjustment:
If the cartridge is not square, the tube can be rotated slightly to obtain the correct
azimuth. Firstly the tube should be released by loosening the two screws on the top of
the arm. Use Allen key 2mm and turn screw for only 90°. Then (being careful not to
push the tube off the armrest) insert the Allen key into the screw on the right side of
the arm (this screw is above the cueing device). Observing the position of the marks
on the tonearm and the cartridge body, this screw should be turned for approximately
45° to alter the azimuth. A clockwise turn of the screw causes a clockwise rotation of
the arm and vice-versa. When the cartridge body is square fixed the top two screws
firmly but do not over tighten as the locking mechanism holds very quickly.