The plate is the
mechanical element that physically supports the disk and prints a rotational
speed of the highest possible accuracy at each instant and over time at the
speeds at which it was recorded. If this does not happen, variations of pitch
are produced in the music played with respect to the original. If a 33 rpm disc
is played at 34 rpm, all frequencies are shifted to treble.
Material of the platter
and shape thereof.
The platters are
made of iron (iron) or antimagnetic materials (zamag, aluminum). The ferrites
have the advantage of presenting a shielding for the pickup cartridge with
respect to the dispersion field of the motor and the transformer if it carries
it. The antimagnetic platters avoid the interaction of the dispersion field of
the phono cartridge magnet on the plate if it were of ferric material.
The platter should
oppose to the maximum to the variations of speed, reason why it is very
important the effect of steering wheel that can represent its mass. For the
above, when talking about a platter, the important thing is not its physical
weight (which would give a balance) but the way in which that weight is
distributed. What is really important in the platters is the so-called moment of
inertia that takes into account the weight and the distance to the center of
rotation of that weight.
0 comentarios:
Post a Comment