- Stable four point suspension.
- Sub-chasis suspended on eighty strands of rubber in the form of
forty purpose moulded ‘O’-rings.
- Trimming screws for suspension adjustment.
- Central fluid damper controls sub-chassis motion and offers
resistive ground-path for acoustic signals.
- For transport lock down screws secure the sub-chassis and seal
the damper.
- 19mm diameter main spindle machined from high-chrome steel
hardened, ground and super finished. Runs in a sealed oil bath.
- Reflex clamping system minimises record resonance.
- 6.5Kg (14.3lb) machined platter with unique Isodamp face.
- Generous use of extensional damping and resistive loop
construction ensure sonic neutrality.
- Adjustable ball feet with optional compliant inserts.
- Four jacking screws built into the sub-platter allow the thrust
bearing to be off loaded for transit.
- Driven by a 3-phase, 6 pulse, inductance motor, with 8 pole
Neodymium magnets and 3 integrated Hall position sensors.
- The power supply houses an electronic controller using a high
performance microcomputer, optimised for motor control. Closed loop speed
control is implemented using a pseudo sine wave commutation sequence and a
proportional-plus-integral (PI) algorithm.
- New design incorporates a 4 layer surface mount technology pcb
with on-board user adjustable speed variation control.
- Large diameter strobe disc supplied allows precise adjustment of
standard speeds.
- Speeds ranges: 33.3, 45 and 78 rpm.
- Dimensions: 520 x 375 x 173.5mm.
- Packing: Substantial case.
- Net weight with power supply: 35.5kg (78lb)
- Shipping weight approximately: 45.5kg (100lb)
Model 20/12 is available in two formats
- MODEL 20/12 Equipped for but not including a pick-up arm.
- MODEL 20/12A As above but fitted with Series 300 Model 312S
precision pick-up arm.
|
A larger and more massive version of our well known Model 20/2. It will accept
nine, ten and twelve-inch arms but is especially directed at the exciting Model
312S. This offers a performance some 27% better than a nine-inch arm in respect
of angular error distortion. The wand and headshell are pressure die-cast in
magnesium and are 27g lighter than they would be in aluminium. Probably the
stiffest and lightest twelve-inch arms ever made these dual problems are at last
addressed and on listening, the benefits of minimal tracking error and harmonic
distortion are clearly revealed. A turntable should address the problems of
extraneous vibrations. These emanate from numerous sources including air and
structural vibration from loudspeakers, groove modulation, stray electrical
fields and mechanical imperfections in moving parts. In the Model 20/12, superb
instrument quality machining is allied with fundamental physics. The higher the
mass and stiffness of a body the less it will flex and vibrate; the duration of
a vibration can be shortened by suitable damping.
Model 20/12 weighs approximately 33.5Kg (73.7lb), significant in relation to its
size because it is density that matters. For example, the same weight of metal
spread over a large enough area would be aluminium foil! The sub-chassis
measures only 20 1/2” (520mm) by 14 3/4” (375mm) but weighs 8.0Kg (17.6lb). Its
thickness, 5/8” (16mm) resists flexing at low frequencies whilst high frequency
resonance is attenuated by efficient extensional damping.
Model 20/12 has no `sonic footprint'. The sub-chassis is suspended on forty
purpose moulded ‘O’ rings which ensure freedom from feedback. A large centrally
placed fluid-damper disciplines sub-chassis movement with a pleasing sense of
security when handling records on and off the platter.
In addition to a cartridge’s electrical output, mirror image acoustic signals
reacted in the arm and record, will pass into the sub-chassis in the course of
dissipation. However the usual closed loop design does not address the problem
of their differing phase so in the Model 20/12 the structural interfaces
concerned have received special attention to provide paths of the required
impedance.
This control of vibration is fundamental to the design of the player and goes
much of the way to explaining the stunning tonal and dynamic neutrality that it
exhibits.
|
