MICRO SIGNAL ARCHITECTURE (MSA)©
Micro Signal Architecture© (MSA) is a cohesive design approach that uses the most advanced available techniques to remove physical and mechanical vibration and electrical noise.
Entering the world of microscopic endeavors there are barriers; for example, the actual method of measurement can deflect the measurement itself. Thought is needed for the measurement system to deliver the best result. For example, numerous research facilities around the globe have millions of dollars invested in microscope systems examining atomic scale objects to enhance our understanding of the physical world.
Images at the nanoscale are extremely sensitive to external vibration even under vacuum. Experiments utilizing sensitive equipment such as; Atomic Force Microscopes, Electron Microscopes and laser scanning systems, require the staff to stand still in the building and machinery to be disabled, when a sensitive image is captured by the microscope. Similar to Hollywood movies of submarine warfare!
In actuality, even foot steps several floors above can transmit through concrete structures and blur the images. This is not an elegant solution for such expensive research, only with the installation of advanced vibration suppression and isolation can the images be retrieved in fine enough detail to show new insights. So how analogous is this to audio?
For analog systems such as the audiophile turntable it is extremely relevant to the performance of the table. For vinyl playback, the enemy of any signal found in the mechanical groove by stylus tracing is also vibration and electrical interference!
Many audiophiles and music lovers lament the lack of isolation on turntables, from entry level to cost-no-object designs. Existing turntable suspension and isolation systems may not achieve the real world performance objectives they claim and listeners experience feedback, information blurring and over-weighted boomy bass response. Modern homes, are not designed for vibration control. In older homes with wooden floors these systems become unstable and do not stop footfall or feedback loops occurring (the classic tiptoe around the suspended turntable else your cartridge mistracks syndrome). This is predominantly due to the natural frequency of these suspension systems not being low enough (0.3hz-1.5hz).
The innovation in Helix 1 lies in the ingenious way the NSM isolation technology is integrated. The turntable and NSM device form a fully acoustic and mechanically balanced system. The result is a precisely designed “mechanical crossover” that harmonizes the forces at play between the incoming external acoustic and mechanical vibrations (the environment) and the self-generated internal vibrations caused by bearings, motor and chassis dynamics (the hardware).
By complex use of recent developments in software measurement technology for Chladni plate analysis and engineering “cymatics”, the team at Audio Union has developed a complex chassis system that effectively damps vibration utilizing a semi-active topology.
The Helix 1 showcases the use of semi-active vibration suppression in a pre-stress accumulation/release (PAR) design. This is a method to convert the strain energy of a vibrating system into kinetic energy, which is then released from the system by means of a dissipative device. This delivers superior isolation to the level demanded by the most sensitive electron microscopes and atomic force microscopes.
The design is semi-active; it does not require adding any substantial amount of energy, is highly efficient and cost effective compared to an active system. Active systems have a tendency to add noise to the operating environment, this is also undesirable. Our approach eliminates this unwanted noise that can disrupt the stylus to record interface.
One of the major influences in the sound reproduction of vinyl play back is mechanical vibration. After all, turntables are mechanical devices. What if a “mechanical crossover” concept could be extended to create a smooth continuous pathway to channel vibrations away from critical areas on a turntable?
Historically mechanical crossovers have been well documented in loudspeaker design for decades. Experienced designers such as Dr Plamen Ivanov Valtchev in Europe have published numerous papers (AES, patents, etc.) on advanced mechanical speaker structures and designs.
Here is a summary of one successful implementation.
Coupling the cone of the speaker to a voice coil bobbin through a compliant section and directly attaching a small lightweight whizzer cone allows the compliant section to serve as a filter! The main cone is not vibrated at higher frequencies as whizzer cone responds to all frequencies, however due to its smaller size; it limits the output at higher frequencies, thereby implementing a “mechanical crossover function”.
From this method we learn the shape and weight of the components influence acoustic behaviour under vibration. Therefore, selection of materials and the suspension elements used determines the crossover frequency and effectiveness!
By extending the mechanical crossover concept to the Helix 1, physical zones can be defined on the infrastructure that focused vibrations away from key areas (platter, bearing, motor, tonearms, floor modes), establishing a smooth continuous pathway to channel vibrations away from critical areas on the turntable!
The Helix 1 has been designed to reject low frequency vibrations coming up from the floor by using the MinusK NSM isolation system and drive higher order vibrations generated through motor noise away from the bearing and platter via a complex coupling to the chassis. For these higher order vibrations local isolation, absorbing, redirecting and suppression technologies are employed including semi-active decoupling from motor vibration.
The Helix 1 is designed to operate flawlessly in non-ideal environments suffering from floor borne vibrations such as older houses with wooden floors, upper floors, attics and any external vibrations which are carried through buildings – even those made from concrete steel, and brick.
Measurement and Visualisation Techniques
By creating a visualisation technique to see these vibrations in real life, the team can see where the vibrations “collected” on a chassis under real life operating conditions.
Chladni Plate Analysis
Extensive use of Chladni plate analysis and the subsequent use of pre-stress in the chassis design allowed the positioning of “anti” vibration zones in critical areas (Motor, bearing and arms) vs trying to damp it with one solo material or less effective broadbrush approaches.
Our experimentation confirmed no “magic bullet” exist for resolving the challenges facing existing turntable designs. It is the precise blending of high-tech materials and topologies which has created the sonic breakthroughs in the Helix 1. Vibration analysis has advanced since the pioneering work of Robert Hooke in 1680 and Ernst Chladni in late 1700’s. Chladni’s Law F=C(m+2n)p can be used in complex eigenmode and wave analysis of turntable chassis. The Chladni method is used by artisans and scientists alike in the creation of musical instruments and engineering solutions.
In simpler terms, “the bearing is the center of the “universe” where “planets” (Motors and Arms) sit on an orbital plane (the chassis/plinth). Vibrate the plane (chassis/plinth) by internal or external means and you get vibration patterns and nodes which become visible to the naked eye using Chladni plate analysis.
By placing the bearing and motor and arms into “optimal zones” where vibration was well damped or controlled we provided the best possible place on the chassis for the susb-system to sit with the lowest possible vibration. Helix 1 chassis research created several eureka moments!
Some resources can be viewed here:
History of Chladni’s Law
Music + Math: Chladni Plates
Helix 1 design is a significant enhancement on state of the art and its motion control defines what will become part of a new breed of “super turntables”.
HTAD – High Torque Adjustable Drive. This is where torque curves and “ballistics” can be adjusted by “musicians and artisans” to “voice” the table for ultimate performance and musicality. This software driven perspective unveils a unique capability for system designers to work with every aspect of a drives performance and open new vistas into music performance.
The precision motor industry is changing rapidly to embracing a software driven architecture. Helix 1 technology is taken from latest developments in sub micron servo drive systems for precision optics and adapted by our engineering team to deliver superior motion control to the Helix 1.
The Helix 1 motor control system is a digital closed loop servo with greater than 16bit resolution. Absolute positioning reading occurs over 120,000 discrete positions of the rotor per revolution. The motor spins several hundred times to achieve one revolution of the platter thus increasing the system resolution by an order of magnitude over a direct drive topology.
In laymans terms; this means at 33/45 rpm platter speeds we have an incredibly high number of checks on the speed stability per second. This information is fed to a super fast microprocessor in the servo control and our custom written software then defines the stiffness and the ballistics of the system and responsiveness of the servo loop. Different ballistics (inertia/force ratios) can be programmed to yield different sonic signatures and sound dynamics. Using a laptop interface we can tune sonics of the drive and control a comprehensive set of variables.
The table can act like a high torque Direct drive or like an underpowered low torque design depending on servo programming. Torque force can be adjusted to suit sonic palettes and the frequency of the drive shifted to areas that are better handled by the mechanical design and vibration control.
Cogging is prevented by a proprietary coil design that smooths the motor to vanishing low levels of vibration. Our motor design team has delivered extremely low motor noise on the Helix 1. We have not found any comparable system able to attain similar results.
The speed is factory set for 33 and 45 and does not need adjustment in normal operation. However if a user wishes to adjust the reference speed a software application via a smartphone/tablet/computer allows adjustment. It is also able to be securely connected to our service technicians for diagnostics and firmware / software upgrades.
Advanced settings are provided to factory trained technicians via stored named reference files for clients custom installations.
The 120mm (four-inch) plinth is made from precision CNC aircraft grade aluminum and structural alloys and weighs close to 50 kg (100Lbs) when assembled. Connected by a series of interlocking plates which are fitted closely to the MinusK suspension system and allow for the mounting of the sub-systems such as motor, bearing, tonearm combinations. A laminated glass plate is used to add ballast and lower the center-of-mass. This glass plate provides visual access to the MinusK suspension for performance monitoring.
The 15Kg (30Lb) platter is made of triple layer of an engineered thermoplastic (made for Audio Union by a European supplier of polymers), and non-ferrous alloy machined to close tolerances. Each high-mass platter is balanced and shaped for lead-in groove and record label.
Special features include an EDR – Edge Damping Ring which damps the platter and LP edge and a damping mat to interface to the LP.
High reliability and ultra low-noise operation were specified as part of the architecture. Audio Union engineer Stanislav Stoyanov developed a new low height, high stability custom bearing design for the Helix 1 using MARAGING STEEL to provide the desired capabilities, precision and low thermal and flex modulus. A single, ceramic ball, located at the bottom of the spindle is used for trouble-free operation on a quiet thrustpad. The high tech lubrication system is sourced from the aeronautical engineering field to ensure low noise operation.
The record clamp is designed for ease of operation and secures the LP effectively on the platter surface and flattens even severe warps in poor quality LP’s. The clamp is a multi-piece design which has a reduced damage profile in the event a user accidentally drops the clamp onto an LP during operation. This was designed for “real-world” use (late night LP sessions and low lighting where operator fatigue sometimes occurs).
A precision single spindle high-torque motor featuring zero cogging is used. The motor can supply up to 100 watts of power for the most demanding control needs. By careful software controlled ballistics the belt system is gently started and bought to rest to avoid premature wear. Speeds are factory set and rock solid.
Dual high damping o-ring belts are provided for stable drive transmission.
Arm Board Assemblies
The Helix 1 supplies two armboards (for dual arms) that are removable and can be predrilled for most commercially available arms or left blank for future use. The armboards are able to be fitted or removed externally with arms mounted. No need to dismantle and recalibrate. The chassis has a damped tubular cross-section underneath which precisely locates the armboards relative to the bearing and platter. This provides a very rigid system with minimal flex and movement.
The Helix 1 is able to function with your choice of arm. We recommend the Schröder CB Arm which has been custom designed to work seamlessly with the Helix 1 and delivers exceptional performance.
The Helix 1 turntable can be mounted on normal non-audio grade furniture (as the suspension system will work independently) and fit in with any architecture and decore.
Any platform the turntable sits needs to support 70Kg (140 pounds) and is at least 620mm wide and 500 mm deep.
Helix 1 includes an owner’s manual that includes step-by-step directions for set up although we recommend working with your authorised dealer.
The table is very easy to set up, use and play.
All controls for normal 33 or 45 operation are located on the turntable top panel.
A separate “control box” motion control servo drive is located in separate 3RU standard rack size housing which can be placed conveniently nearby or out of sight.
The unit comes pre-calibrated to precise speed for 33 and 45 from factory. The drive system monitors the speed constantly over 130,000 times per revolution to deliver direct drive like accuracy without speed drift. Speed adjustment is accessed via simple USB interface on the Control box and can be done remotely or onsite using a simple GUI connected to the USB direct or via secure Wifi.
Version shown here is anodized silver/black halftone edition. Unit is available in all black and all silver anodized configurations.