Unsurpassed musicality. Inspired design makes the most difficult task appear simple www.spiral-groove.com
As a medium for capturing music, vinyl remains unsurpassed. To convey its rich and nuanced potential, a turntable must, at the very least, achieve a high degree of control over the speed of its platter and the transfer of energy among its components. Noise is the nemesis, an uncompromised signal emerging from a silent background the goal.
"After reviewing quite a few cost-no-object analog rigs over the last few years, we’re absolutely smitten with this one...the SG-2 offers a HUGE sound for a relatively affordable price. It’s simple, beautiful and offers an exquisite level of fit and finish. We chose it as our Product of the Year in the analog category, and we recommend that you audition it before writing a check for one of those mega-buck contenders" Tone Audio
Spiral Groove turntables rely in part on mass to control noise. Stainless steel and aluminum lend our ‘tables heft and solidity, an effective first-line defense against errant vibration. But mass alone cannot eliminate noise; though the metals we’ve chosen store and release energy in predictable ways, they need help in order to dissipate it effectively. We provide that assistance by sandwiching together the layers of our platform with a proven damping agent.
Mechanical isolation contributes an additional measure of control. Motor, tonearm, and platter occupy discrete layers within the platform, a tactical separation that prevents noise generated by one mechanism from contaminating another. This strategic alliance — rigidity, compliance, and isolation — lays the groundwork for one of the quietest and most responsive turntables on the market today.
Because a turntable’s platter is where the rubber meets the road, its design is of critical importance. Unlike most other turntables, our ‘tables’ spindle and platter bearing are decoupled and yet precisely aligned. Severing the connection between these two critical components dramatically reduces the transfer of energy between them, lowering still further our ‘tables’ noise floor while ensuring unparalleled depth and specificity of image.
Moreover, the Spiral Groove platter is driven on the rotational plane of the bearing, which eliminates wobble. A thick phenolic layer forms the bulk of the platter, followed by two thinner layers, one of vinyl, the other of graphite. A clamp made of stainless steel and anodized aluminum snugs the record to the graphite, providing the stylus with an absolutely flat work surface. This is a platter to which you can entrust even your most pampered LPs, over and over again.
Powering the platter is a 12-volt AC motor and outboard analog sine-wave generator. Toward our goal of maximum control, we build drag into our platter and then provide enough torque to spin it precisely. Our sine-wave generator liberates our motor from the fluctuations of wall current and guarantees accurate rotation at both 33 & 1/3 and 45 revolutions per minute.
The SG2 embodies everything that Spiral Groove believes to be important in a successful turntable design. The basis of the Spiral Groove design is the constrained layer platform approach. Three dissimilar thickness aluminium layers, sandwich two layers of damping material, forming a dense, stiff, and well damped platform to which you can precisely mount the working bits of the turntable. Each “ functioning “ part of the turntable is provided with it’s own isolated layer to carry out its particular function.
To the robust bottom layer of aluminium are mounted both the height adjustable feet and the motor mount assembly. The motor being the only “active” component of the turntable, it is first decoupled- mounted to a round aluminium plate- making for a solid and silent sub-assembly. This is then suspended with tensioned elastomers from the bottom aluminium layer, creating a very quiet de-coupled mass mounting solution. Further, the part of the adjustable foot that interfaces with your support is now de-coupled from the rest of the SG2 using a similar elastomer technique. This provides the first barrier that any outside mechanical energy must try and pass through to get into the turntable. The middle and thickest layer of aluminium in the SG2 provides the stiffness and mass to which we mount the main bearing and platter assembly. Here, mounted to a massive field, the platter is free to rotate, free of flexure & noise. The top layer, farthest away from any other component, is where the tonearm resides. The armboard of the SG2 is an island of quiet, for any extra energy that resides here, will also make it to the stylus. It is no easy feat making a self-generated, rotating, and utterly quiet microphone stand. Which at the end of the day, is very much how a tonearm & turntable system operates.
The Spiral Groove armboard for the SG2 is mounted from underneath with six bolts, bypassing the bottom two layers of aluminium to keep the three layers all mechanically isolated. The armboard can be drilled for any tonearm that is 10” and will accommodate most 12” arms. The tolerances are such that you can have multiple arms “ pre set-up” on multiple armboards to switch out for your favourite cartridge selection.
We believe that the SG2 represents significant value in the world of high performance turntables. It shares so much in terms of design implementation & materials with the SG1.1, it can be difficult to understand how the SG1.1 might significantly surpass what has been accomplished with THIS model. However, one listen and the magic found in the execution details of the SG1.1 tell the whole story.
With an extraordinary 20-year guarantee Spiral Groove provide a confident launch pad for buying a product for life.
TECHNICAL SPECIFICATIONS Aluminium platter ring for increased speed stability Inverted sapphire disc/ceramic ball bearing for low noise and long wear Electronically selectable speed control: 33 1/3 & 45 rpm Removable arm board Spindle de-coupled from bearing for optimal mechanical isolation of record Platter driven at rotational plane of bearing for wobble-free revolution Low voltage/high torque AC synchronous motor Adjustable, sound-damping, aluminium feet
Dimensions: 18.5" W x 15" D x 4.5" H (470 mm x 380 mm x 115 mm) Weight: ~50 lbs. (~23 kg)
Taking the same path, where the SG2 leaves off, the SG1.1 begins. The differences between the SG2 & SG1.1 turntables are seemingly small, as the two turntables share so many of the same components. However, where they differ pays large dividends in performance. The primary difference one sees in the silver coloured SG1.1 is that the body is comprised of two separate constrained layer platforms. These two, mirror imaged platforms are separated by four carefully positioned elastomers, which mechanically decouple the two assemblies.
Like the SG2, the feet and motor are attached to the bottom two layers for maximum isolation from the rest of the turntable. The SG1.1 motor is mounted to the thickest layer of the lower constrained layer platform where the motor is de-coupled & mounted to a thick bronze ring. The ring is mounted in such a way that it sinks any energy into that layer, further dissipating residual noise from the motor. The higher mass stainless steel adjustable feet are mounted to the lowest layer on the SG1.1 and help to create further noise filtering over the SG2 aluminium versions of the same design. As with the SG2, the thickest layer of the upper platform is where the bearing & platter are mounted, completely separated from the lower platform that houses the motor & feet. It is this separation of the active motor assembly from the upper layer that is largely responsible for the distancing of the SG1.1’s performance over the SG2. The top most aluminium armboard layer is the same as the SG2, but with a lovely twist, so to speak.
The armboard of the SG1.1 is fitted with a stainless steel bayonet mounting system, that with the push of a button and a slight twist, is easily removed from the turntable. This unique system allows for a multitude of arm and cartridge set-ups to be instantly useable, a simple & perfect re-attachment – with a twist its fully locked in and secure. Yes, once a cartridge & arm are fully set up, detachment & re-attachment with the bayonet mount, will provide perfect alignment, every time.
So how do the two turntables differ in performance?
As one would hope, the SG2 is as much a Spiral Groove table as the SG1.1. As such, they share the same sonic signature & attributes. However, the lower residual noise floor on the SG1.1 reveals not just nuance, but sheer clarity that is only missed in the SG2 when compared to its larger brother. The SG1.1 breathes both low level & high level dynamics more convincingly. This is apparent in the way the SG1.1 provides superior low frequency extension & drive that is felt, not just heard. One also might suspect that the SG1.1 is a more exciting presentation, and indeed it is exciting. However, the authoritative calm of the SG1.1 is a window into the soul of the performers, removing itself from the equation, just letting what ever is on the vinyl do the talking, and nothing more.
TECHNICAL SPECIFICATIONS Stainless steel platter ring for increased speed stability Inverted sapphire disc/ceramic ball bearing for low noise and long wear Electronically selectable speed control: 33 1/3 & 45 rpm Quick-change bayonet-mounted arm board Spindle de-coupled from bearing for optimal mechanical isolation of record Platter driven at rotational plane of bearing for wobble-free revolution Low voltage/ high torque AC synchronous motor Adjustable, sound-damping, stainless steel feet
Dimensions: 18.5" W x 15" D x 4.5" H (470 mm x 380 mm x 115 mm) Weight: ~70 lbs. (~32 kg)
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
Balanced Force Design is at the heart of Spiral Groove and the basis for all products we manufacture. Indeed, it is one of our most important “assets”. The result of our design method is product homeostasis, where sheer performance, manufacturability, intuitive interaction, durability, and beauty exist in balance. Balanced Force Design is elemental and simply described, however the implementation is far from easy.
The first seemingly obvious goal is to establish, in fundamental terms, the function of the item being developed. i.e. a rotating platter at a constant 331/3 RPM. The next goal is to identify anything that would compromise or impede functionality. A constantly rotating platter is but one operation within the matrix of operations in an active turntable. Identifying and understanding the inter-related dynamics of all its parts is a much bigger and more complex task.
Finally, the most difficult goal is balancing the solutions while not creating new problems in the process. When accomplished, the result is a naturally elegant product that provides a level of performance, service life, and ease of use far beyond it’s seemingly simple form.