Through the end of Nov 2017 - get a FREE Centroid tonearm with a new SG 1.2
Spiral Groove SG 1.2
The SG1.2 body is comprised of four aluminum layers in two independent constrained-layer platforms. These two mirror-imaged assemblies, separated by four carefully positioned elastomers, function as a single platform. The feet, with Strange Attractor technology and low frequency damping, are attached only to the bottom layer. The second layer, which is separated by rigid damping material, provides a stable platform for the motor. The upper half of the SG 1.2 body isolates the platter and tonearm in a similar fashion. The bearing/platter assembly attach to the 3rd plate from the bottom. The top plate, which is separated by a rigid damping layer, provides the tonearm mount. This allows motor, platter, arm, and the furniture the turntable rests on, to remain isolated from each others' vibrations while maintaining critical alignment between them.
The unique Spiral Groove bearing is made from the same case hardened steel used for an F1 racing car's crankshaft. Utilizing material made for high heat, high speed, high wear applications might seem unnecessary for a turntable bearing, but, it's actually ideal for several reasons. For one, it allows us to machine an extremely small bearing gap for superior platter stability. Secondly, since both bearing components are made from the same material, the clearance between bearing parts remains unchanged by temperature variations. In bearings made with dissimilar materials, varying rates of expansion and contraction result in variations in the stability of the platter. This can’t be controlled unless a heater is used to stabilize the temperature. Our bearing design assures consistent high level performance without complicated compensation systems. And the steel we use is so durable that we confidently offer a 20 year warranty.
The Spiral Groove bearing incorporates a steel ball and sapphire thrust plate so the entire weight of the platter rests on the very small contact area between the ball and sapphire. This spot is vulnerable to wear and is a source of noise. To further insure the bearings durability and smooth operation we use a custom designed magnet system that reduces the weight on the sapphire to about 2 Lbs. This is a major contributor to its smooth operation and low noise.
Like Strange Attractors, the SG1.2 platter is built with irregular shapes and carefully chosen materials. The Graphite and Aluminum assembly provides a non-resonant surface for the record to mate to. Energy transfers quickly from the record through the platter and is dissipated internally. A 14 inch stainless steel drive ring provides the inertia of a much heavier platter. The speed stability it provides can be heard in the SG1.2's rock solid sound stage. Our simple and reliable clamp assures close contact between the record and platter surface and helps flatten warped records.
Our arm board has a lovely twist, so to speak: the SG1.2 arm board is fitted with a stainless steel bayonet mount. With the push of a button and a slight twist like a camera lens, it is easily removed from the turntable. This unique system provides the enthusiast fast and easy arm-and-cartridge swaps with accurate re-attachment. Once a cartridge and arm are set up and adjusted, detachment and re-attachment with the bayonet mount provides solid, locked-in, perfect alignment every time.
The extremely low residual noise floor of the SG1.2 reveals not just nuance, but sheer clarity. It breathes both low level and high level dynamics more convincingly. With very controlled authority it reveals low frequency extension and drive that is felt as well as heard. The SG1.2 exudes an authoritative calm that is a window into the soul of the performers. By removing itself from the equation it lets the vinyl—and only the vinyl—do the talking.
SG 1.2 Features and Specifications
- Oversized stainless steel platter drive ring for increased inertia and speed stability
- Inverted sapphire disc/hardened steel polished ball bearing for silent, long wear
- Platter driven at rotational plane of bearing for wobble-free rotation
- Spindle de-coupled from bearing for optimal mechanical isolation of record
- Magnetic levitation system to reduce platter weight on the sapphire thrust bearing
- Graphite and aluminum platter
- Low durometer round belt
- Quick-change bayonet mounted arm board
- Electronically selectable speed control with fine adjustment: 33⅓ & 45 rpm
- Low voltage/high torque AC synchronous motor with proprietary phase control to eliminate cogging.
- Adjustable, decoupled, aluminum and graphite feet
- Dimensions: 18.5” W x 15” D x 4.5” H
- Weight: approximately 80 lbs.