NEW SEMPER SONUS EPICYCLICAL "IDLER" DRIVE TURNTABLE


"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 – idler drives – 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 10-pole BLDC motor, epicyclically driving the aluminum platter through a low-elasticity rubber drive wheel. The motor is attached to a telescopic cradle using Sorbothane rings for vibration decoupling.


The platter, of medium weight (3.3Kg), is constructed from aluminum and acrylic 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 opposing neodymium magnets. To top it off, we use a two layer rubber / cork mat, for further isolation.

Everything ties together at an aluminium / acrylic composite chassis X-frame, for rigidity and vibration damping. The frame itself, bolts onto a plinth made from steel reinforced concrete, where all other parts – armboard, sideboards, power and control electronics – are also bolted to, on precision located mounting points.

The inboard power supply, line filters the mains supply before converting it to 12V DC and stabilizing it. It then feeds  the motor controller, which features electronic speed  switching (33/45), along with quick spin-up 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.

OUTSIDE EVERYTHING IS BLISS AND CALM

Complexity is hidden, or rather function doesn’t dictates form. We strived for a classical, contained appearance, able to subtly fit into any decor and not scream about itself.

Beautiful wood panels side frame the turntable, while all other surfaces are covered in Alcantara for a truly “no-fingerprints left” finish and, if being honest, for a difference!

ARM / CARTRIDGE COMBINATION

Our standard combination includes a Jelco SA-750EB arm and a Denon DL-110 cartridge. However, armboards for other arms can be supplied instead, with no additional charge.

OPTIONAL DUST COVER

For protection from dust – and little fingers – an optional dust cover is available. It features a novel tilt/slide damped hinge that allows for a more compact vertical footprint. Also included is a useful holder for LP covers, enabling their display while the record is spinning.

SPECIFICATIONS

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 measures used to evaluate turntables ever since, 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 ocurring speed drifts; Rumble is also mostly useless, as the backgound noise from the records usually surpasses the noise coming from the motor / bearing.

But as relevant as they might be, the way a turntable platter responds to quick changes of pitch and volume, strongly shapes the signature of the sound as we hear it, yet no one measures it.

Aditionally, some of the intensity of the vibrations on a record’s groove, as perceived by the stylus, is partially lost along the mechanical path of shaft-platter-LP-stylus-arm-plinth, and we don’t have a clue on how much…

We are working on it. We want to measure it, give it a name and draw up a target, so that we can reach it and improve, again and again.

Price: around 5800 EUR with tonearm...