The Linn
Sondek LP12 transcription turntable is designed and manufactured to extract as
much information as possible from the modern long playing record. It is, quite
simply, the link missing in so many play-back systems between your ear and the
reocrded performance.
The design
is elegant yet functional, relying on precision machining rather than complex
electronics and gadgetry to provide the highest level of performance while
maintaining the ultimate in reliability.
If you can appreciate the differences between
listening to a record on a good system and hearing something that approaches
live music, then the logical place to start is with the Linn Sondek LP12.
A product of
integrity which offers proven value and performance.
The Linn
Sondek LP12 is specifically designed and manufactured to obtein the best
reproduction from the modern high fidelity long-playing record.
General
Description
The Linn
Sondek LP12 transcription turntable is designed for free-standing use with the
finest specialist component high fidelity sound reproduction systems.
The unit is
designed for a long operating life and should, if treated properly, last longer
than any other part of your hi-fi system.
We cannot
emphasise strongly enough the importance of prospective customers receiving a
fair demonstration before purchase. We suggest placing any transcription
turntable beside the LP12. fit same with arms and cartridges, listen to both at
the same volume setting through the same system and decide for yourself which
sounds more like real music.
The unit is
guaranteed under the conditions which apply in the country of purchase. In
addition to any statutory rights the customer may have, we undertake to replace
any parts which have failed due to fault manufacture.
Type
Precision
built single speed transcription turntable mounted in a solid kiln-dried
hardwood low resonance plinth system with counter-balanced hinges and moulded
perspex lid.
Bearing
The LP12
employs an exclusive single point bearing running in an oil bath (world patents
pending). [The hardened and ground steel spindle runs on a mirror finished
hardened, ground and lapped thrust pad.]
The spindle
is hardened tool steel. The thrust plate, which must withstand a pressure of
2,5 tons per square inch, is top grade steel, machined, hardened, groun, and
lapped to a mirror finish. The sides of a bearing housing are lined with a
hard, very low friction plastic. Between this liner and spindle is a thin film
of oil. The only surface to surface contact is at the single point where the
spindle rest on the thrust plate. Since
this is also the center of rotation, the velocity at the point of contact is
very low. A direct result of this low velocity is low friction, negligible
wear, and extremely low rumble.
Motor
24-pole
precision synchronous low noise motor. Speed is 250/300 rpm, depending on mains
frequency. The motor is fully electrically and mechanically screened and
isolated from the main turntable assembly.
Speed Accuracy
The
synchronous motor of the LP12 locks-on to the 60 Hz AC line frequency. Over a
day's time, this line frequency, and the speed of the turntable, will typically
change by less than ±0,04%.
While it
might be possible to obtain greater "accuracy" by using a
quartz-locked servo-controlled motor, it should be pointed out that our goal is
to obtain the best possible audible performance, not to build a laboratory
standard rotating platform. Speed consistancy is far more important than speed
accuracy. Errors in accuracy of up to three percent often go unnoticed, while
rapid changes in speed of only a few hundredths of a percent are audible. By
definition, a servo-controlled motor maintains its speed accuracy by constantly
changing and correcting its speed.
Drive
The platter
is driven via a flat precision ground chloroprene rubber belt by a 24-pole, low
noise, synchronous motor. The 24-pole design of the motor allows it to run at a
relatively slow speed (300 rpm vs. 1800 rpm for a four-pole motor). The
combination of the slow speed and the individually tuned motor assembly reduces
rumble to a minimum. The beltdrive acts as a filter to prevent any residual
motor noise from reaching the platter.
Flutter is minimized by the use of a machined metal drive pulley
(concentricity 0,0004") in place of the usual cast metal or molded plastic
variety.
The pulley
is machined from the same material as the platter. Thus, all parts within the
loop of the drive belt have the same coefficient of expansion insuring that the
speed will be constant over a wide range
of operating temperatures.
A flat
precision-ground chloroprene rubber belt driven by a drive pulley mounted on
the motor. Due to the materials selected, the rotating elements within the
drive belt loop are such that the ratio is temperature stable. This means that
a constant speed will be maintained over a wide range of operating
temperatures.
Suspension
The platter
and arm board are fixed to a floating sub-chassis suspended by resilient
mountings in the double-damped triple point suspension.
Chassis
The main
chassis is heavy gauge non-magnetic brushed satin finished stainless steel. The
sub-chassis is formed from mild steel pressing welded for maximum rigidity and
stove enamelled to give corrosion protection.
Base Plate
The base
plate is constructed of heavy gauge, satin finish stainless steel. The motor of
the LP12 is attached directly to this non-magnetic plate. Besides providing
additional hum shielding, this plate acts as a mechanical energy sink. Motor
vibrations, that would have been transmitted along the belt into the system,
are instead converted into harmless mechanical noise that ia dissipated over
the entire surface of the stainless steel plate.
Subchassis
The
platter/bearing assembly and the arm board are mounted on a rigid steel
subchassis. It is isolated from the base plate, motor, and external vibrations
by a fully adjustable three-point spring suspension.
Arm Board
The arm
mounting board is constructed of a center ply layer sandwiched between two
layers of hard board.
Base
In contrast
to the typical flake board base construction, the LP12 base is crafted from
solid kiln-dried hardwood. Hardwoods are chosen for their ideal resonance
characteristics and stability. Provision has been made for proper arm cable
dressing to control vibrations that may travel up the arm cable, by-passing the
suspension.
Plater
305 mm
(12") diameter non-magnetic zinc aluminium alloy die casting machined
throughout with optimum peripheral mass distribution. Total weight is
approximately 4,5 kg (10 lb). A choice
of mat is available: a felt type suitable for tag cueing, or a radial-ribbed
thermo-plastic moulded mat for standard use.
Rumble
Rumble is
-60 dB unweighted, with reference to a 10cm/sec 1000 Hz signal. The weighted
rumble measurements used by most manufactures are virtually useless in
evaluating the performance of a turntable. Weighting systems effectively ignore
rumble at very low frequencies. This subsonic rumble may not be as audible as
rumble occuring at 200 Hz, but its side effects can be quite audible and even
more serious than a little low frequency noise. Sunsonic rumble may excite
arm/cartridge resonance and cause mistracking. The amplifier, trying to
reproduce this rumble, wastes a great deal of power. The speaker cone is forced
to move beyond its linear operating limits. The end result is increased IM
Distortion. We contend that, if you must use a rumble measurement, it should be
unweighted and the velocity and frequency of the reference signal should be
specified. Anything less can, and often does, cover up poor performance.
Wow and Flutter
The LP12's
wow and flutter is less than 0,04% (typically, wow is less than 0,03% and
flutter is less than 0,015%)
Dimensions
445 x
355 x 140mm (17½ x 14 x 5½ in)
Approximately
7 cm (2 ½") clearance is
required at the rear of the unit and approx. 25 cm (10") above the unit to
permit convenient opening of the lid.
Specifications
Type: single speed transcription turntable
Speed: 33 ⅓ rpm
Motor: 24-pole precision synchronous low noise motor
Drive: belt-drive
Plater
Type: Non-magnetic zinc-aluminium alloy
die-cast
Platter
Diameter/Mass: 305 mm (12")/4,5 kg
(10 lb)
Rumble: -60 dB (unweighted)
Wow and
Flutter: less than 0,04%
Power
Requirement: 220-250 V or 110-125 V,
50-60 Hz
Power
Consumption: 3,3 VA
Dimensions
(W x H x D): 445 x 140 x 355 mm (17½ " x 5½" x 14")
Weight: 10 kg (22 lbs)
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