What Makes A Great Turntable?
What are the key construction items and features that make the top vinyl record players “great” vs. turntables that make Eddie Vedder sound like Justin Bieber (without the auto-tune)? There are many factors, from the components themselves to the accuracy and noise margin of the analog signal itself – which usually ends up digitally converted and amplified in some fashion and sent through any number of speaker or headphone types. In most vinyl record player reviews these are the key components in making the record player accurately reproduce the intended sound.
And we won’t even go into the factors involved in the quality of production of the records themselves or the cleaning and care of the vinyl. Those topics will be reviewed in more detail in a future article, but suffice it to say, they are critical to the overall sound as well.
So What To Look For?
What this means is that while one high end turntable may sound great in one system, it may not sound so great in others. Aside from the non-turntable factors, which depend on the end users method of building an audio system – turntables basically have the following components that contribute to the ability to accurately reproduce the originally intended sound.
- Plinth or Base: The plinth is the base of the turntable – it provides the foundation that everything else is built upon. It provides the stability and isolation required for quiet and consistent rotation of the record on the platter. Plinths can be made of wood (or MDF), plastic, or metal, resting on feet often tipped with rubber.
- The Platter: The platter is the part of the turntable that the record sits upon. They are typically made of steel or aluminum, with aluminum the preferred choice for higher end systems. The platter is spun by the motor at various revolutions per minute (most commonly 33 and 45, and occasionally 78). A mat is often set upon the platter to act as a buffer between platter and record, but this may not be necessary depending on the turntable. Platters are usually removable.
- The Drive Motor: The platter is rotated by a belt-drive internal or external to the platter, or direct drive where the motor is attached directly. Belt-drive is considered superior for noise reduction but direct drive is typically used in “professional (DJ)” units because of their instant torque and accuracy.
- The Tonearm: The tonearm, or ‘arm’ sits off to the side of the platter and supports the cartridge and stylus, a typical radial or pivotal arm designed to allow the stylus to trace the record in an arc from its outside edge towards the center. The tonearm can be straight or curved. There are also tonearms known as linear or parallel tracking arms which trace the record from the outer edge in toward the center in a perfectly straight line, exactly as the record was cut during the manufacturing process. Such tonearms are usually reserved for the highest end turntables, and most of the turntables on the market today feature a standard radial or pivotal tonearm. The tonearm typically has a counterweight to help adjust the tracking force – optical tracking is neither too light or too heavy and is critical to record sound and wear. Tonearms can be manual or automatic. Some prefer the manual for the audiophile grade sound.
- Cartridge: The cartridge is the piece that holds the stylus and attaches to the tonearm in a headshell. Besides the stylus, it contains other parts such as the coil, cantilever, suspension, and magnet. There are 3 primary technologies used in cartridges, the Ceramic, Moving Magnet (MM) and Moving Coil (MC) designs.
- A ceramic cartridge is the cheapest to make, and generates an electrical signal through a piezoelectric pickup.
- A MM-type cartridge utilizes a magnet on the end of a cantilever holding the stylus to translate tip movement into an electrical signal. This is the more common configuration in modern hi-fi turntables, as the tracking force is lighter than ceramic and can more accurately reproduce at all frequencies.
- The MC-type cartridge is somewhat the inverse of the MM type – a stationary magnet and coils move within the mechanism to create the electrical signal. They typically produce a lower output than the MM design and may require additional pre-amplification. This type is mostly seen in very high-end turntables.
- Stylus: This is the piece that tracks in the vinyl grooves – where the rubber hits the road. They typically come in 2 tip types – elliptical and spherical. Elliptical types tend to be slightly more expensive, but sit deeper in the grooves. The tips are usually made of one of two materials, diamond or sapphire. Diamond, being much harder, has much better wear characteristics and are found in most higher end cartridges. Both, however, need to be replaced on a regular basis to maintain sound quality and avoid record groove damage.
- Pre-Amps: A turntable may come with a pre-amplifier built in to boost the electrical output to normal audio signal strength, but many do not. If they don’t, they may require an external pre-amp to boost the signal to input to a stereo receiver. Many modern receivers no longer have a phono line-in with a built-in pre-amp.
- USB or Bluetooth: There are modern turntables with built-in USB connections that enable an easy way to convert records to a digital, which may be useful in converting old records that are hard to find in a digital format. Bluetooth can enable a wireless playback, although the sound quality would be questionable – this seems better suited to digital formats.
- Speed Selection: Almost all turntables come with the ability to play 33 1/3 or 45rpm speeds, sometimes with a manual belt adjustment or by switch. Some turntables also enable playing older 78rpm vinyl but there are not many models with this feature.