SEMPERSONUS TE2

EPICYCLIC IDLER DRIVE TURNTABLE

INNER BEAUTY

Turntables are back with a vengeance, but time doesn’t stand still. Technology’s pace allows us to revisit problems and solutions of the past with new eyes and new means.

We looked at one of the older and most cherished drive systems – the idler drive – and proceeded to iron out its kinks and foibles with modern technology and materials. The result surprised us and will surprise you.

Starting with the drive system, motion is supplied by a BLDC motor, epicyclically driving the aluminum platter through an urethane drive wheel. The motor is attached to a telescopic cradle using sorbothane rings for vibration decoupling.

THE PLATTER

The platter, of medium weight (3.4Kg), is constructed from aluminum with the major mass around its circumference for a greater Moment of Inertia. Its underside is covered in butyl rubber to quell any “ringing”. It rotates on an inverted bearing design, its weight supported by twin ceramic spheres. To top it off, we use a two layer rubber / cork mat, for further isolation.

THE PLINTH

Everything ties together at a stainless steel cross-frame, for rigidity and precision. The frame itself attaches onto a MDF and acrylic multi-layered plinth. At the plinth, all other parts -- armboard, enclosure, power and control electronics -- are bolted onto precision located mounting points.

sempersonus te2 plinth detail_auto_x2.png

THE MOTOR

The inboard power supply, line filters the mains supply before converting it to DC and stabilizing it. It then feeds the motor controller, which features electronic speed switching (33/45), along with quick start and quick stop characteristics.

The correct speed is constantly monitored and accurately maintained thanks to feedback from a 1000-step optical encoder.

At the same time, the right amount of torque provided – i.e. the absolute minimum required at all times – is continually adjusted based on feedback from the current levels required by the motor.

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OUTSIDE, EVERYTHING IS BLISS AND CALM

Complexity is hidden, or rather, function doesn’t dictate form. We strived for a classical, contained appearance, able to subtly fit into any decor and not scream about itself. Alcantara or Leatherette fabric frames the turntable, while the top is covered in brushed aluminum.

TONEARM MOUNTING

Adapters for mounting any tonearm can be supplied at time of order for no additional charge. Additional adapter boards can be ordered for a modest fee.

COLORS & OTHER FINISH OPTIONS

Standard Available Colors :

Alcantara – black or anthracite

Leatherette – dark brown or burgundy

Custom Alcantara or Leatherette finishes are available for an additional cost of $110. A polished brass Logo is optional for $135.

DUSTCOVER

For protection from dust an optional hinged dust cover is available for $500.

SPECIFICATIONS

Epicyclic drive
BLDC motor with digital, relaxed closed-loop control system
33 / 45 / 78 rpm capability (78 with pitch control in 0.5% steps)
Twin ceramic inverted bearing design
Chrome-plated, induction hardened 16mm platter shaft
Constrained layer MDF plinth construction
Stainless steel cross-frame chassis
Supports tonearms between 9”-12”
Aluminium + rubber damped platter construction
Height adjustable damped feet (4)
Exterior finished in Alcantara or Leatherette and brushed Aluminum
Platter Weight: 3.5Kg / 7.7 lbs

Total Weight : 17Kg / 37.4 lbs
Dimensions (without tonearm and feet):

52(w) x 41(d) x 12(h) cm / 20.5(w) x 16.1(d) x 4.7(h) in

PERFORMANCE

Although, we don’t believe that numbers are the only game in town, we do measure them, which is not very common today. Wow & Flutter, along with Rumble have been the most common measurements used to evaluate turntables, but we know there’s more to sound than just those two.

In fact, those two can be misleading: W&F is an average, scarcely revealing the magnitude and frequency of the occurring speed drifts. Rumble is also mostly useless, as today, the background noise from the records usually surpasses the noise coming from the motor / bearing.

However, at least for a ballpark / baseline perspective, we do measure them. Below, the plots from a recent W&F test can be seen. We used the Ios PlatterSpeed app along with Dr. Feickert’s 7″ test record and a 40sec sample.

And the test results made us proud !