Buying a turntable 101

SO you want to buy a turntable? This is always an exciting journey as there are so many choices available at all price points today.

What’s a turntable, to begin with? It’s an analogue music waveform transcription device to facilitate the extraction of music waveforms stored on a record to reproduce music. In simple terms, a turntable will have a tonearm, cartridge, platter and motor.

The choice of drive mechanism
The drive for a turntable platter is usually provided by a motor. The spinning motor generates a vibration that needs to be isolated or damped because it can interfere with your music. There are three main technical designs used to isolate vibration, namely:

1. Belt drive: This is the most popular and cheapest implementation for a turntable. The platter is connected to the motor via a rubber belt that isolates motor vibration from the platter. Small, fast-spinning low-torque motors are often used in belt-driven designs as it depends on the moment of inertia or flywheel effect from the platter rotation to keep the platter spinning with minimal stress on the motor. Early designs used DC servo motors whilst modern designs can be elaborate, with AC motors powered by a regenerated AC sine wave power supply.

Given that there is a degree of slip between the belt and platter, pitch accuracy and speed accuracy may be an issue with lesser designs. It’s arguable that the belt used may generate some sonic attributes to colour the music resulting from slippage. Start-up time varies and the platter may take a few seconds to achieve the desired playing speed.

Examples: Rega Planar 3, Micro Seiki RX-5000, VPI Prime, Techdas Airforce One and Kronos Sparta.

2. Idler drive: This is a small rubber wheel that is an intermediate between the motor and platter, or at times, the idler wheel is attached to a powerful motor directly. Some designs drive the idler wheel via a belt to reduce the vibration from the faster spinning motor. Drive is provided when the idler wheel presses against the inner side of the platter. Vibration from the motor is absorbed by the idler wheel. The direct contact between the idler wheel and platter transfers the rotational energy efficiently. Once it starts spinning, it just keeps going and going with lots of torque.

Idler drives can be prone to rumble. Low-friction precision-machined bearings with a substantial plinths are often used reduce rumble. Frequency dependent synchronous motors are often used, hence speed stability is a function of the electricity grid.

Examples: Garrard 301/401, Thorens TD-124, EMT 927 and Lenco L75.

3. Direct drive: The most elaborate drive system for turntables. In simple terms, the platter is directly coupled to the motor system sharing a common bearing on the same axis. Absorption material beneath the platter is used to damp the motor vibration. Early designs were prone to cogging from rotational irregularities but this has since been mitigated with improved designs incorporating a continuous magnetic field from doughnut shaped magnets, which have more stator windings for a more even field, as well as integrating the platter as part of the actual rotor design to be driven entirely from the stator windings. The integrated platter motor effectively spins at the same speed which the records demand, hence having a lower noise floor compared with both belt and idler drive systems. Direct drives offer superior quartz-controlled speed stability, a good sense of solidity and almost instant start-up to accurate speed.

Examples: Technics SL-1200GR, Micro Seiki DDL-60, Denon DP-80, Audio Technica AT-LP120 and VPI HW-40.

Plinth design, mass and materials
There are two main schools of thought on vibration isolation when it comes to plinth designs. The most popular designs being:

1. Fixed plinth: Here, the platter and tonearm sit on a fixed plinth, with the motor located onboard or outboard. The variations in fixed plinth designs can be extreme as purveyors of lightweight plinths (or absence of) such as Rega believe that lightweight materials dissipate energy faster to reduce colouration whilst the heavyweights (eg. Techdas, Micro Seiki and TW Acoustics) depend on mass to prevent resonance while absorbing vibration. Sandwiched composite materials (acrylic, brass and wood) are used by Gold Note to tune the resonance signature of their plinths for a desired sound colouration.
2. Suspended sub-chassis: Mounting the platter and tonearm from the plinth via a suspended sub-chassis enables the stylus to transcribe from the record isolated from vibration coming through the plinth. The sub-chassis usually sits on a three-point spring suspension using metal, rubber or elastomers. The Linn Sondek LP12 and Oracle Delphi series are classic examples of a three-point suspended design whilst Kronos takes the suspended chassis design to a whole new level with its novel suspended layers supported by four turrets.

Heavier platters will put less stress on the motor with their innate higher amount of inertia contributing towards the flywheel effect and this is heavily capitalised upon by many high-end manufacturers such as Techdas, Micro Seiki, TW Akustics and Continuum Audio Labs.

All materials have different natural resonance frequencies. If possible, it’s important to match your musical preference with the materials used as an acrylic plinth will sound very different from a wooden or granite plinth. Composite lamination adopted by some manufacturers as well as choice of damping materials and bracing will all have an effect on the resulting sound.

The same applies to the platter where you see materials such as glass (Rega), acrylic (Pro-Ject), sustarin (Gold Note), aluminium (VPI) and even gunmetal (Micro Seiki) being used. It is not unknown that high-end turntable makers employ metallurgists to formulate alloys with the best sonic attributes for their turntables.

Tonearm and cartridge
You won’t get much of a choice when it comes to tonearms – with most turntables, the tonearm usually come preinstalled and matched to the overall design. Turntables such as the Dual CS-440 or Denon DP-200USB have automatic tonearm cueing and return features which are excellent choices for novices wanting a worry-free option. Some of the high-end turntables and vintage turntables have the option to mount different tonearms by changing the arm-board.

All-in-one
Given that space is at a premium nowadays, one can minimise clutter by opting for an all-in-one lifestyle turntable that comes with an onboard phono stage (like VPI’s Player). You can take it a step further – some modern all-in-one turntables are equipped with an analogue-to-digital converter with USB connection to digitise your records or even Bluetooth (Sony PS-LX310BT) to connect directly to your streamer or wireless speakers.

What to buy?
It’s always good to start with a budget and keep an open mind in terms of the choices available. For the final consideration, buy new or used? Previously, only belt-drive and direct-drive turntables were available new but with the vinyl revival, we also see the emergence of vintage idler drives (Garrard 301 by SME Engineering) being offered as newly assembled from new old stock inventory.

Buying new is the safest option, as you get support and warranty. You will get the latest in technology on drive systems as well as precision-built components, including quieter, energy-efficient motors and stable power supplies. Modern turntables tend to be voiced towards the current preference for a more accurate sound profile. Used or vintage turntables have their appeal as they do sound different from most modern turntables, partly due to differences in materials used, and are voiced for the analogue musical preference of yesteryears. Do your homework for availability of parts, local repair skillsets and online support database if you are considering a used or vintage turntable.

At the end of the day, there is no perfect turntable, only compromises. It is best to audition a few within your budget before narrowing down to the best fit for your system.