Project Description

SPIRAL GROOVE REVOLUTION

A serious ‘entry-level’ turntable for very high quality analog playback; the Spiral Groove Revolution incorporates sleek lines and bold colors in a “modern meets retro” package.

The SG Revolution is what happens when you blend just-the-right materials with uber-careful acoustics and electronic design.

The combination of materials and careful design are primary forces in the SG Revolution Turntable. Multiple layers of impedance matched material in the body, platter and feet, deliver an ideal playback environment for the LP.

The Revolution body is a sandwich of aluminum and delrin. This rigid platform creates a tightly coupled yet isolated connection between platter and tone arm. Its aluminum platter, with varied interior and exterior angles, is topped with a delrin record surface to create an isolated energy sink for stylus-induced vibrations. A low voltage AC synchronous motor and highly evolved motor control system assure constant speed and minimum noise. Graphite, aluminum, and engineered elastomer, in the height-adjustable feet provide excellent isolation from external disturbances.

This carefully orchestrated combination of high mass, extreme solidity, superior speed stability and non-existent noise floor, converge in the Spiral Groove Revolution to deliver the cutting edge of LP playback.

REVOLUTION TURNTABLE

Extremely dense and rigid layered body of aluminium and delrin. Multi-layer platter of graphite and aluminium. Decoupled record spindle, threaded record clamp, magnetic bearing load reduction system, 33 and 45 speeds, height adjustable isolation feet, removable arm board.

£15,000
  • Weight – 78 lbs. excluding tonearm and power supply
  • Size – 20” W x 15” D x 7” H
  • Body – Aluminum and delrin sandwich
  • Platter – Aluminum with delrin record surface
  • Platter bearing – Hardened steel low profile inverted bearing with sapphire thrust plate.
  • Feet – Graphite, aluminum and elastomer – height adjustable
  • Motor – AC synchronous
  • Power supply – AC sine wave generator and amplifier. Phase corrected and frequency adjustable.
  • Speeds – 33 – 45 rpm, adjustable
  • Removable arm board
  • Magnetic weight reduction system in platter
  • Guarantee – 10 years mechanical, 3 years electrical

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.

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.) is found in SG1.2.

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 20 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 the SG1.2 perform as designed. Once the table has been leveled and the speed checked for accuracy, it stays 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.