1036 Chapter 27
footsteps on the floor, door slamming, or other vibra-
tions in the area.
Operating the Laser Turntable. When a record is
placed in the drawer and the play button pressed, the
record tray closes and the LT scans the disc to identify
the various bands or cuts. The bands are displayed on
the front panel Record Profile LCD display. A single
vertical line above the bands indicator shows the posi-
tion of the laser pickup head. The vertical indicator
travels across the record as it is played, showing its
exact position on the record, and which band is playing.
On the initial scan the laser head moves from the
inside (spindle) to the outside track while marking the
bands. The machine then moves into the first band and
measures the distance from the head to the record
surface. After a few seconds the record will begin
playing from the beginning.
The LP can repeat the same record up to five times,
repeat a cut, listen to a segment of the cut, play a single
grove segment repeatedly, or play selected bands in any
order.
When a record starts to play, the message window
displays the rpm of the platter. When a record is
playing, the display shows the elapsed running time, the
elapsed time of the current cut, the remaining time of
the side, and total time of the side.
27.9 Record Care Suggestions
One of the most effective ways to keep the sound from
the record free of noise and unwanted pops and clicks is
to keep the groove and the stylus clean. The causes for
dirty records are obvious; accumulation of airborne
dust, finger grease, cigarette smoke, and anything that
can be attracted by the static charges that exist on the
surface of the vinyl disc. The dirt around the playback
stylus is mainly due to raking the groove. Dust particles,
as they settle down on the record surface, are attracted
by the stylus, especially if it has a static charge on it.
Better cartridges have their styli electrically grounded to
bleed any static potential from the cantilever assembly
to ground.
27.9.1 Brushes
One method to keep room dust out of the record groove
is to have the cartridge work with the dust-collecting
brush. In sliding over the surface of the vinyl record, the
electrically insulated brush produces a static charge of
its own that attracts and holds the dust particles from the
surrounding area. The stylus cantilever, which is metal-
lic and electrically neutral because of grounding, stays
clean and free to vibrate and track the modulation of the
groove.27.9.2 Record-Cleaning MachinesThe groove modulations in vinyl LP’s are so small, on
the order of the wavelength of light, that any compound,
be it liquid or solid, will cause distortion in the repro-
duction of those grooves. The diamond stylus can be
equated to a rock, and the vinyl record to Jell-O. Picture
a rock running through jell-o at a high velocity. Any-
thing that changes the way this rock moves through the
Jell-O will cause changes in the recorded sound.
In the groove is a conglomerate of fungus, mold,
dirt, ash, pollution, mold release compounds, various
cleaning fluids and preservatives, etc. All these
substances affect the way the stylus reads the groove
and will affect the sound. A good vacuum cleaning
machine will allow you to scrub the record with
cleaning solution and then vacuum the record surface
clean of the fluid carrying the contaminates away with
it. A record cleaned on a good vacuum cleaning
machine is microscopically clean and will sound it.
One of the great shocks in audio is the first time you
hear a record you know very well cleaned by a vacuum
cleaning machine. The sound is cleaner, clearer, crisper,
with the sound of the hall or acoustic space very easy to
hear. A clean record will not wear out. It is not the
stylus that ruins the records it’s the stylus going through
grunge and pressing the grunge into the vinyl grove that
kills the sound of records.
Vacuum record cleaning machines all work the same
way; a record is placed on a turntable, the turntable
turns the record while the machine or the operator
scrubs the record, the vacuum nozzle then sucks the
contaminated fluid off the disc. A higher price gives
you quieter operation or greater sophistication in appli-
cation of cleaning fluids. In the end the result is pretty
much the same. VPI’s HW-16.5 (in production for
almost 30 years), Fig. 27-31, is an inexpensive record
cleaner. The VPI HW-27 Typhoon Record Cleaning
Machine is twice as powerful as other cleaning
machines. It includes a 7.9 A 120 Vac vacuum motor
and an 18 rpm turntable motor, Fig. 27-32.
It is strongly advised that before using any cleaning
device the instructions be followed precisely and some
experimentation be done on a few records before the
entire library is cleaned or covered with a preservative
coating. A word of caution, if too much record preserva-
tive is used, it will do more harm than good. Not only
does the excess of material not lower the surface noise,