Telos

Analog


turntables


Spiral Groove: SG1.1

Turntable 33, 45RPM with bayonet mount armboard.

Vinyl remains unsurpassed for reproducing music. To convey vinyl''s rich, nuanced potential, a turntable must have precise speed control and operate without producing mechanical or electronic noise. The goal is an un-compromised signal emerging from a silent background. Spiral Groove builds two turntable models, identical in design concept using decoupled mass, purpose specific materials, and precisely designed construction to eliminate noise and give precise speed control for ideal playback.

Turntable Art and Science

Vinyl remains unsurpassed for reproducing music. To convey vinyl''s rich, nuanced potential, a turntable must have precise speed control and operate without producing mechanical or electronic noise. The goal is an un-compromised signal emerging from a silent background.

Spiral Groove builds two turntable models, identical in design concept using decoupled mass, purpose specific materials, and precisely designed construction to eliminate noise and give precise speed control for ideal playback.

Noise Control

In the turntable body aluminum is the first-line of defense against errant vibration, storing and releasing energy in predictable ways. Assembled into a sandwich of differing thicknesses and separated by proven damping material, the result is a dense, stiff, and silent platform. The sound-absorbing, mechanically solid, yet isolated layers (i.e.: the motor, turntable bearing, arm-board, etc.) are found in both the SG2 and SG1.1.

The platter is where the music begins. Spiral Groove's platter is belt-driven at the contact plane of the bearing to eliminate wobble or oscillation. Both the SG2 and SG1.1 platters utilize a 14 inch drive ring of either aluminum or stainless steel to guarantee exceptional speed stability. Spindle and bearing are decoupled yet precisely aligned. A thick phenolic layer forms the bulk of the spinning disc, topped by layers of vinyl and graphite. These materials act together to dissipate the energy generated by the stylus in the groove, all but eliminating the “stylus talk” common to most turntables. Threaded record clamps, made of stainless steel or anodized aluminum (depending on the model), snug the record to the graphite to create intimate contact for vibration transfer. Together, these features dramatically reduce the turntables' noise floor, giving unparalleled depth and specificity of image.

Stylus Talk

Pops and clicks on records occur when the stylus encounters a piece of debris in the groove and "plays" it as if it were part of the record. Such encounters also generate energy that, in some platters, is reflected back into the vinyl, moving the stylus and sending a second signal milliseconds after the first. This "echo" is so close in time that the pop or click is not heard as two pops, but as a louder and longer single event.

And, reflected waves don't only come from dust or dirt in the grooves. The movement of the stylus through the groove also sends energy into the record which, on insufficiently damped platters, comes back through the record to the stylus, causing a higher noise floor and coloring the sound.

Spiral Groove spares no effort to prevent mechanical-electrical feedback. SG platters are carefully engineered and constructed to dissipate energy. And they do: SG platters dissipate reflected energy so it can't get back to the stylus. Vinyl is a lot quieter and the music clearer when played on Spiral Groove.

Speed Control

All of our turntables use a 12 volt, AC synchronous motor driven by our proprietary outboard motor controller. The controller transforms AC wall current to DC and generates its own sine wave with switchable frequencies and adjustable phase to precisely control the motor. At startup the motor runs at full torque until it reaches speed when the current is reduced for smoother and quieter operation. The LED speed indicator flashes during start up, becoming steady when 33⅓ or 45 RPM is reached. Speeds are independently adjustable by 10% with 18-turn pots accessible on the turntable.

Please note: there is no further adjustment, calibration, or “tweaking” required to make either the SG2 or SG1.1 perform as designed. Once the tables have been leveled and the speed checked for accuracy, they stay set up indefinitely. Get right to setting up the tone arm and cartridge (even these operations are easier and faster with Spiral Groove's Centroid tone arm) and enjoy a new level of reproduction from your favorite records.

The SG1.1 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 assembly. 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 stainless steel feet, attached only to the bottom layer, allow leveling and contain an elastomer insert to prevent external vibration from entering the turntable. The motor is attached to the layer above it on a de-coupled solid bronze ring. This creates a rigid, stable platform for the motor that “floats” between the surface it sets on and the platter/arm assembly above it.

The upper half of the SG 1.1 body holds the platter and tonearm in serene mechanical isolation from the motor on the platform below it. The unique Spiral Groove platter bearing, isolated on its own aluminum plate, is made from the same case hardened steel used for an F1 racing car's crankshaft. While utilizing material made for high heat, high speed, high wear applications would seem unnecessary for a turntable bearing, it is actually ideal for several reasons. For one, it's dimensional stability 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 different rates of expansion and contraction cause the size of the bearing gap to change. This changes the stability of the platter and can’t be avoided unless a heater is used to stabilize the gap. The highest level of performance from the Spiral Groove bearing is assured without additional complications. And the steel we use is so durable that we confidently offer a 20 year warranty.

The top-most aluminum layer holds the arm board, which has a lovely twist, so to speak: the SG1.1 arm board is fitted with a stainless steel bayonet mount. With the push of a button and a slight twist 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 SG1.1 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 SG1.1 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 1.1 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
  • Low durometer round belt
  • Electronically selectable speed control with fine adjustment: 33⅓ & 45 rpm
  • Quick-change bayonet mounted arm board
  • Low voltage/high torque AC synchronous motor with proprietary phase control to eliminate cogging.
  • Adjustable, decoupled, stainless steel feet
  • Dimensions : 18.5” W x 15” D x 4.5” H
  • Weight: 75 lbs.

The 35Kg SG1.1 is a belt-driven, split-plinth design with an onboard AC synchronous motor driving a 11kg platter of graphite, vinyl, and phenolic. The SG1.1's clever tonearm-mounting system allows for simple installation of most any arm, Spiral Groove's complementary Centroid tonearm is designed for optimal system performance.

Build quality is camera like - in a nutshell superb. Tell-tale signature? One of the quietest turntable-tonearm combos you will experience. Stereophile Class A Rating (Vol.35 No.11). "Black backgrounds, delicate highs, natural attacks and decays, and rock-solid bass".

Elegant proportions and clever hidden features. No gimmicks.

Allen Perkins cements his place among the handful of the world's best analog systems designers. Having started with SOTA, his pedigree remains unchallenged.



Dohmann: Helix 1

A breakthrough in analog playback design and execution.

A new turntable from an accomplished team who decided to push the envelop in analog playback. Genuine engineering breakthroughs which create a new bar for performance in turntables. The Helix 1 is a showcase for MSA (c)  - Micro Signal Architecture - A new way of thinking borne from the electron micrsocope world where unwanted vibration is the enemy of resolution.

Helix 1 rewards the listener with the closest facsimile to master tape yet realized. Audio Union's engineering facilities and listening rooms use several studio reference level and highly modified master tape systems that were used to compare the Helix 1 to a range of other well-known turntables.

The specifications of the Helix 1 demand the ultimate in noise suppression and isolation systems to allow the turntable and pickup arms to deliver the micro-signals buried in the vinyl grooves on well authored LP’s.

Every aspect of the turntable design requires the preservation of the micro signals found in the groove of the LP to be retrieved with as little modification and distortion as physically and electronically possible.

Döhmann Helix 1 turntable by Audio Union incorporates several engineering advances to deliver the lowest resonance profile for any pickup arm and LP combination.

Features include:

MSA - Micro Signal Architecture©

NSM - Negative Stiffness Mechanism Vibration Isolation 0.5 Hz (Fz) Vertical 1.5 Hz (Fz) Horizontal

MCT - Mechanical Crossover Technology

TMP - Tri-Modal Platter system

EDR - Edge Damping Ring

TDS - Tone arm Damping System

RTS - Resonance Tuned Suspension

DLC - Diamond Like Coating Amorphous Material Bearing Friction Modifier

HTAD - High Torque Adjustable Drive Speed Selections 33, 45 RPM (78 RPM by request)

Velocity Adjustment Lock – Speed is constantly calibrated over 130,000 times per second to deliver precise 33.33 or 45.15 rpm (factory default).
 

Dimensions and Weight

Helix 1 - Table Width 600mm (24”) x Depth 480mm (19”) x Height 250mm (10”)

Helix 1 – Control Box Width 483mm (19”) x Depth 480mm (19”) x Height 133mm (5”)

Standard 3RU (19 inches) Configuration. Power 120 VAC, 50/60Hz 2 amps or 220/240 VAC, 50/60 Hz 1 amp

Combined shipping weight is 80Kg (shipped in 2 custom fabricated boxes).

Recommended installation requires a surface capable of supporting up to 80Kg (160 pounds) and a 620mm (25”) wide x 500mm (20”) deep surface for the isolation platform to be able to move freely.

Factory set speed selection by push button for 33 1/3 or 45 rpm.

The Helix 1 allows 33, 45 and if required 78RPM and a wide variety of engineering adjustments to create “audio bliss” that is very user friendly and easy to operate.

Multiple arms up to 12 inch are accommodated with ease of operation and setup assured. Removable arm boards allow simple interchange and calibration.
 

The new Dohmann Helix 1 turntable from Audio Union sets new benchmarks for performance in Analog. Coupled with the Schroder CB arm this table offers unsurpassed sonic results. An immediate distinction in terms of speed accuracy is noticed by experienced listeners. This is not a direct drive sound rather it presents as an organic rightness with macro and micro dynamics that astonish.

Simple to operate and able to perform in rooms where other tables fail such as wooden floorboards which create feedback loops on tables with less effective isolation solutions.

This table deserves an audition. Visit www.audio-union.com for more details



Spiral Groove: SG2

Mass Loaded Turntable 33, 45 RPM

Spiral Groove products are developed and manufactured in Berkeley, California. Founded in 2005, Spiral Groove is a design and manufacturing firm dedicated to building high-performance audio products with a focus on analog. Since its inception Spiral Groove has been building world-class turntables and tonearms that have received numerous awards and accolades worldwide.

The platter is where the music begins. Spiral Groove's platter is belt-driven at the contact plane of the bearing to eliminate wobble or oscillation. Both the SG2 platter utilizes a 14 inch drive ring of aluminum to guarantee exceptional speed stability.

Spindle and bearing are decoupled yet precisely aligned. A thick phenolic layer forms the bulk of the spinning disc, topped by layers of vinyl and graphite. These materials act together to dissipate the energy generated by the stylus in the groove, all but eliminating the “stylus talk” common to most turntables. Threaded record clamps, made of stainless steel or anodized aluminum (depending on the model), snug the record to the graphite to create intimate contact for vibration transfer. Together, these features dramatically reduce the turntables' noise floor, giving unparalleled depth and specificity of image.

Specifications:

Unique Spiral Groove platter bearing, isolated on its own aluminum plate, is made from the same case hardened steel used for an F1 racing car's crankshaft.

External motor drive electronics.

  • 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
  • Low durometer round belt
  • Electronically selectable speed control with fine adjustment: 33⅓ & 45 rpm
  • Quick-change bayonet mounted arm board
  • Low voltage/high torque AC synchronous motor with proprietary phase control to eliminate cogging.
  • Adjustable, decoupled, stainless steel feet
  • Dimensions : 18.5” W x 15” D x 4.5” H
  • Weight: 25 kgs.

Building on more than 20 years of high-end audio design experience, co-founder Allen Perkins uses a development method he calls Balanced Force Design® to conceive and manufacture every product. With Balanced Force Design, the interaction between idealized design concepts, materials, and engineering possibilities are balanced in components that are pleasing to look at and operate, extremely reliable, and always convey the music. It’s a balance of physics, engineering, science, art and intuition.

Well built, simple to set up, and bulletproof in operation, the SG2 uses a five-layer chassis—two thin layers of damping material separated by three aluminum plates—and a thick, anti-vibration platter comprising layers of aluminum, an impregnated phenolic, vinyl, and graphite.

The bearing assembly has been optimized to eliminate radial movement and prevent stray magnetic fields from interacting with the cartridge. "The SG2's dramatic timing, authoritative midrange, and superb resolution of detail worked to present music with an urgency and wave-like drive", said Brian Dramkroger of Stereophile. Through the SG2, "[a recording] became a performance," (Vol.33 No.6)

See also http://www.tonepublications.com/analogaholic/spiral-groove-sg-2-turntable-4/



Spiral Groove: The Revolution

New Product Coming soon!

The Revolution - Coming soon!

New turntable design coming soon!

Balanced Force Design is the heart of Spiral Groove. It is the guiding principle for all of the products we manufacture. To create a product in homeostasis: ultra-high performance, intuitive user interaction, durability, and beauty in equilibrium.

Balanced Force Design is a simple concept, though the implementation of it is an exacting discipline that brooks no short-cuts or omissions. First we clearly define the function of the component being developed, i.e.: a silent platter that rotates at a constant 33⅓ RPM. Next we identify any mechanical or electronic effects that would compromise or impede this function—taking into account the other systems simultaneously operating in a turntable. Next, to identify and understand the inter-related dynamics of all of these parts, multiple iterations of listening, measurement, and analysis is required. Then its balancing, adjusting, modifying, and re-analyzing the task-specific individual solutions until they work together in perfect harmony without adding noise or vibrations.

After accounting for theoretical, mechanical, electronic, and physical manufacturing constraints, prototyping, testing, and repeating the process to reach Beta or Alpha versions, the end product embodies elegance, outstanding performance, long service life, and ease of use. Not all of the design elements that contribute to these qualities are obvious in, say, the clean outline of the turntables' surface form. But their presence is clearly evident when you turn it on and listen to music.

Balanced Force Design is Allen Perkins’ personal insight and intuition into concepts, materials, and inter-related forces. This method and philosophy has been embodied in his turntables and tonearms for over 20 years. Today Allen continues to invent, design, and refine in a search for the limits of analog reproduction.

Features

  • Abiding love for good sound and audio systems that deliver it
  • Detailed understanding of music, audio components and psycho-acoustics
  • 30 years of audio engineering development
  • Unrelenting, single-minded pursuit of perfection



Dohmann: Helix 2

Dual Belt Drive Turntable with Negative Stiffness Suspension
 

The Helix 2 is engineered to deliver unparalleled performance in analog playback. It raises the benchmarks for noise reduction and preservation of signals due to its unique Micro Signal Architecture (MSA) design.

The complex chassis design of the Helix 2 incorporates technological innovations to eliminate cloudiness and time signature smear inherent in a turntable’s basic design premise.

This fresh approach addresses each aspect of noise and vibration suppression using the latest in visualization techniques, engineering concepts, and patented technologies.

Other innovations in the Helix 2 design include:

  • Active transmigration of vibrations away from the bearing and platter.
  • Motor drive control over fluidity and dynamics eliminates motor “hunt and seek” disruption to platter rotation.
  • Adaptation and integration of a Negative Stiffness Mechanism NSM©, a unique isolation system originally developed by Minus-K and customized in conjunction with Audio Union, for isolation of low frequency floor vibrations.

  • Audio Union understands all listening environments are unique. The Helix 2 is designed to operate flawlessly in non-ideal environments such as older houses with wooden floors, upper floors, attics where external vibrations are carried through buildings - even those made from concrete, steel, and brick.

    Our passion for recording and playback of music has driven us to innovate and create the Helix 2 to satisfy our desire to obtain a new reference in analog playback. We are confident you will appreciate our meticulous attention to detail from the very first note you hear in your own listening room.

    The Helix 2 turntable can be situated on any furniture; fit in with any architecture and décor with the capacity to support 70Kg and provide shelf space at least 480mm wide and 400 mm deep.

One step under the class leading Helix 1 but still a no compromise design. Sonically its in the top tier of turntables. Simply amazing performance!

Impervious to external vibration with the full MinusK Suspension inside. If it works for electron microscopes then hear what it does to a turntable!

A stunning addition to the Dohmann line now within reach of serious listeners without the bling budget.