Getting back to
basics
For all its seeming
complexity, there are really only three basic requirements of any well designed
turntable:
That the turntable
platter rotate at a constant unvarying speed
The the tone arm
enable the cartridge to trace the microscopic undulations in the record groove
freely and accurately
That it be extremely
reliable and trouble free.
The turntable proper
Let us examine the
turntable mechanism first. In addition to rotating at an exact speed, a well
designed turntable should be able to play a record with:
Minimum rumble -
that is, it should not contribute any mechanical noise of its own to the music.
It should have
undetectable wow and flutter. That means it must be free of slow and fast
variations in pitch caused by momentary variations in speed.
Belt drive plus.
The primary cause of
turntable rumble is the transmission of vibrations from the drive motor to the
tone arm as it tracks the record.
Over the years,
various methods have been devised to reduce rumble. Perhaps the simplest, most
affective and reliable is the use of a belt drive system. By connecting an
elastic belt from the drive shaft of the motor to the rim of the turntable
platter, while the belt acts as a very effective mechanical filter damping out
motor vibrations.
However, there is
one drawback to this otherwise admirable system. It lacks sufficient torque or
start up power to actuate the arm lifting and cycling functions quickly and
efficiently.
To remedy this
problem, Elac has designed an ingenious drive system with an idler assist
called Belt Drive Plus, which is incorporated in the new Elac PC 830.
An idle wheel driven
directly by the motor brings the platter up to speed quickly and indexes the
arm over the lead-in groove of the record. As soon as the tone arm descends and
the stylus touches the record, the idler is disengaged end the turntable operates
in the belt drive mode only.
To reduce wow and
flutter, the Elac PC 830 couples the motor to a heavy (4:4 pounds), dynamically
balanced turntable platter. The mass of the platter in rotation creates a
flywheel effect and very effectively smoothes out any momentary speed
variations.
It's worth noting
that the flat, precision ground rubber drive belt used in the Elac PC 830 is
resistant to heat and humidity. Moreover, long term dimensional stability is
insured through the use of an automatic belt release that reduces tension on
the drive belt when the turntable is not in use.
Precise and
continous speed monitoring is provided for via an illuminated strobe and a
pitch control that is adjustable over a range of ±3% of nominal speed.
In addition, the
Elac PC 830 satisfies another vital, but often overlooked, requirement of a
well designed turntable. It incorporates a dual element, tuned suspension
system that provides maximum isolation from external vibrations, thus rendering
it virtually immune to acoustic feedback as well as other sound bluring sources.
The well behaved
tone arm
Just as a well
designed turntable should do nothing more than rotate silently at a precise,
unvarying speed, so should the tone arm assume a completely bening role. Its
only function, to present the cartridge to the record without let or hindrance.
But this is more
easily said than done. For today's better cartridges play at such very low
tracking forces, often 1 gram or less, that many tone arms are hard pressed to
cope with them. As a result performance can be seriously degraded.
To operate properly
at these very low tracking forces, a tone arm must be very light and rigid. In
addition, it should have a very low moment of inertia, so as not to impede the
movement of the stylus in the groove. But that's only the begining, a well designed
tone arm should also have:
Very low mass,
especially at the head where it counts most.
Very low tracking
error. That is, its design geometry should permit it to remain as nearly
tangent to the groove as possible, at any point on the record.
Skating or side
thrust compensation to keep the stylus centered in the groove.
The ability to
function properly with a wide veriety of cartridges
A cueing control for
simple and precise manual operation
To successfully meet
all these requirements. Elac has designed a superb new tone arm for the PC 830.
Special alloy,
tubular construction makes it very light and rigid while significantly reducing
mass. Freedom of movement has been optimized through the use of microprecision
ball bearing races in both the vertical and horizontal pivos enabling the tone
arm to perform faultlessly with most lightweight, high compliance cartridges.
To provide greater
stability and further improve tracking, the tone arm is dynamically balanced
which has the added advantage of making turntable leveling non-critical. The
offset angle (geometry) of the head minimizes tracking error and a positive
contact, slide-in cartridge mount permits precise adjustment of stylus overhang
to further reduce distortion.
To insure perfect
centering of the stylus, in the groove at any point on the record, a highly
effective antiskating adjustment is provide for conical elliptical and CD-4
styli. Thus uneven groove wear and distortion are materially reduced. A viscous
damped cueing control sets the tone arm
down gently anywhere on the record. And the same gentle lowering action also comes into play during automatic
operation.
The finishing touch
In the final
analysis, however, any first rank turntable is more than a collection of
features. It is a study in human engineering. It should respond instantly and
effortlessly. It should enable you to play a single record or a batch of
records whit a minimum of fuss and bother. In short, it should never get
between you and the music .
Specifications
Drive System: Precision ground belt plus idler assist
Operational
Mode: Single and multiple play
Speeds: 33-⅓ and 45 rpm
Speed
Adjustment: ±3%
Wow and Flutter
(DIN) ±0,6%
Rumble DIN
Unweighted ; better than 44 dB
Weighted : 64 dB
Tone arm: 205 mm
tubular alloy
Tracking Error: less than ±1,4 degrees
Tracking Force
Adjustment: 0,5 - 4 grams
Platter: 285 mm diameter zink diecast
Platter Weigth: 4,4 pounds
Power Requirements:
Power
Consumption: 15 watts
Dimensions
(W x H x D): 435 x 175 x 350 mm
