Sota Sapphire turntable

Sota the belt-drive turntable.

There is no mystery about the function of the turntable. Its purpose is simplicity itself; to rotate at a fixed speed with maximum isolation from acoustic and mechanical feedback. Yet because of the extraordinary sensitivity of the stylus-groove onterference, and its position at the very source of signal creation, the simplicity of the function belies the difficulty of conception and execution.

The real mystery is why there are virtually no fully-engineered, fully-built, and musically legitimate turntables. And none is priced within the range of the majority of audiophiles.

To know how the Sota Sapphire Turntable was conceived and designed is to appreciate its integration of engineering, machanics, physics, and daily audio usage. The architect of the Sota Sapphire, responsible for the engineering and for the design, R.A. Herman, who brings his years of audio experience to the task. Armed with basic concepts and preliminary drawings, Herman collaborated with one of the country's leading audio specialists, D. Fletcher of Sumiko, Inc. With a background in experimental physics and years of intimate experience and testing of the very best cartridges and tone arms.

 

At Sota Industries , we approached the design of the Sota Sapphire Turntable not as an exercise to discover new cosmic scientific principles, but to combine known conceptions with imaginative execution in a more intimate way  than has hitherto been achieved. We claim no breakthroughs more profound or more esoteric than the idea of Dynamic Stability, the guiding principle of the Sota Sapphire … idea which dominates the creation of the Sota Sapphire Table, it is about this integity, and control of forces; the proper turntable must react in a predictable and mathematical fashion. What are called "third order resultant influences" are what cause time-domain and phase-domain irregularities and give tables of inferior quality their "colorations" and "sonic signature" . The issue is not naively to try eliminate every possible rection, but to determine the vectors of forces so that the system is prepared to deal with them so that they decay harmlessly and noiselessly.

 

The suspension

If there is one area in which the Sota Sapphire Turntable makes a fundamental contribution to the world of audio ,, it will be in the suspension/sub-assembly system. If there is one area that dramatically needs the assistance of Newtonian physics, it is here. The issue are inertia and isolation and the most beneficial distribution of inertia forces. We decided to break conventionand opt for a 4 point suspension because 4 points have greater dynamic stability  than 3 points, the Sota 4 pt. sub-assembly is much more difficult to excite mechanically. To reinforce this stability, we make the sub-assembly much more massive than normal, using more than 20 lb of lead and additional low resonant, rigid material. The enormous mass itself, unique to belt-drive turntables, maximizes inertial stability while the 4 pt. approach provides the balance of "mass loading". Mass-loading means that we have a consstantly-balanced mass system,no matter the weight of the tone arm. With a choice of variable weights, the Sota Sapphire is the only turntable to our knowledge which allows the user to maintain balance by adjusting for any specific tone arm.

 

The platter

The platter, itself a kind of mini-suspension system for the record, was designed as painstakingly as was the sub-assembly. The platter on the Sota Sapphire is a unified, integrated system. It begins with a one-piece casting made of a complex alloy selected for its mass, strength, and machining properties. Even though Q is already low, a special synthetic material makes upp the platter pad and guarantees total immunity from standing waves and ringing. We discovered that building the proper platter is only the first part. It is further necessary to make certain that each platter is optimally balanced for the particular bearing and table on which it will rotate. That is why we call our platter an "integrated" system. Each platter is individually balanced at the factory and shipped fitted to the bearing. It is not removable by the user because the platter and bearings are matched. Removal will be done only at the factory.

 

Evrything revolves around the bearing. It is the center, the heart, the very pivot of the system. As one classic table proves, if you have the bearings right, you will survive, even if the suspension, platter and motor are not of the same quality. The Sota bearing is inverted, which means that errors in machining are not multiplied by the length of the thrust shaft, which in our design doea not move. Located at the very center of gravity on th eplatter is the sapphire thrust plate. The thrust shaft ascends from the sub-assembly and is topped with the ball bearing held firmly in place. The sapphire disc balances the platter and rotates on the ball bearing. The thrust shaft becomes,, in effect, a platform for motion, not an agent of motion. "Throw-out error" practically vanishes and age takes little toll of the sapphire, second only in hardness to diamond. Unlike the commonplace steel tips, sapphire has a known crystalline structure, capable of being ground to 1 wavelength of light accuracy. It keep friction to the very minimum,it doesn't deform, it keeps the contact area extremely low and, finally,it has better wear characterictics than steel. In a word, it is the best material for the purpose.

 

Specifications

Motor;  Brushless DC Servo for high torque and extreme low noise

Suspension:  massive 20 lb, sub-assembly with 4-point system for ideal of dynamic stability and static balance. Center of gravity at the center of platter.

Platter:  heavyweight 11,2 lb, single-part cast alloy with compound damping. Designed for optimum fly-wheel effect and individually balanced

Bearing:  Thrust pad; sapphire dis accurate to 1 wavelength of light over diameter. Thrust point; hardened chrome/steel ball accurate to 1/10,000,000 inch

Transmission:  belt-drive using high-technology complex, low-tension belt.

Shaft:  Hardned steel, hand-mayched to sintered bronze sleeve.

Speeds:  33-1/3 and 45 rpm. Electronically switchable with fine tuning.

Rumble: less than -60 dB unweighted 9with ref. To 10 cm/sec, 1 kHz)

Wow and Flutter::  less than ,04% RMS

Suspension Frequency:  2,55 Hz

Dimensions (H x W x D):  7-1/2" x 20-1/2" x 16-1/2"

Weight:  20 kg (44 lbs)