Spiral Groove (and SRA isolation)SG1.2usedSpiral Groove SG 1.2 flagship turntable with Centroid Tonearm & Free Custom SRA stand !!Below Blue Book!! Includes for Free a $6,000 tonearm AND FREE $2,500 custom SRA stand which elevates the performance a few notches. Also if buyer wants I can ship this to Alan Perkins to check it...22500.00

Spiral Groove SG 1.2 flagship turntable with Centroid Tonearm & Free Custom SRA stand !! [Expired]


no longer for sale

Below Blue Book!!
Includes for Free a $6,000 tonearm AND FREE $2,500 custom SRA stand which elevates the performance a few notches. Also if buyer wants I can ship this to Alan Perkins to check it out and verify it is in perfect condition and then ship to buyer. 

Spiral Groove's new flagship SG1.2 turntable with Centroid tonearm (second brand new Centroid tonearm available for purchase as well).  Buyer to pay shipping/insurance as well as any Paypal fees.  Also INCLUDED FOR FREE is the custom $2,500 SRA turntable stand - included in price. Extra new Spiral Groove belts included.  I have a cardas clear 1.2m RCA to RCA tonearm phono cable available for purchase as well.

Purchased brand new; used for less than one year (has been boxed and stored). Retail Price $30,000 (without tonearm) Audiogon Blue Book Price $26,250.63 (without tonearm)
Centroid Tonearm  Retail $6,000 Blue Book $2,868.63

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.


Spiral Groove Centroid Tonearm (Extra Brand New One Available for $3,000)


Structural rigidity and the efficient dissipation of unwanted mechanical energy are hallmarks of the Spiral Groove tonearm. Three criteria have determined the choice of tonearm materials: low mass, high strength, and the ability to transfer energy quickly away from the cartridge. Moreover, in order to give that energy somewhere to go, SG has established a direct link between cartridge & mechanical ground.

No other tonearm available today dispenses with wayward energy more efficiently or effectively.

Optimal rigidity and the exceptionally fast transfer of energy from headshell to ground are just two of the reasons the Centroid tonearm delivers unsurpassed speed, dynamic energy and tonal purity. Another is its overall balance. Unlike most other tonearm designs Spiral Groove use advanced computer modelling to simulate the forces exerted on the arm as the cartridge tracks the record. Understanding these forces dynamically has enabled SG to compensate for them mechanically. This approach is called 'Balanced Force Design' (see below), and with it’s principles they have greatly improved tracking & optimized the performance possible from any cartridge.

In order to deliver their best performance, high-end cartridges require tonearms that facilitate precise alignment. On the Centroid tonearm the Overhang, VTA, Azimuth, Zenith, Anti-skate control and tracking force are all easily & precisely adjustable. Spiral Groove, in addition, supply a proprietary mirror setup gauge to enhance the performance of any manufacturers cartridge, as well as ease the set-up of the arm.

The Spiral Groove tonearm was designed not only to set new engineering standards but also to please the user. Like the turntables themselves the tonearm is exceedingly user friendly. Originally the Centroid was conceived to make a perfect marriage with the Spiral Groove turntables, but in their wisdom SG have also designed a version of the Centroid arm with a Universal fitting arrangement, thus allowing all vinyl users access to Spiral Groove’s ground breaking performance – irrespective of the choice of table used.

As with all of Spiral Groove’s products the Centroid is simply a “servant to the music”.

TECHNICAL SPECIFICATIONS
Balanced Force Design™ - modal analysis places centroid at bearing point
Counter-weight design minimizes moment of inertia by staying close to bearing
10" pivot-to-stylus distance
Swiss made sapphire bearing cup and steel pin
“Zero tolerance” unipivot bearing design
Multi-layered, damped arm tube
Low mass, high strength aluminum/carbon fiber arm tube
High purity copper internal wiring
Overhang, VTA, Azimuth, Zenith, Anti-skate & Tracking force all easily adjustable
Precise mirror set-up gauge included