Have you ever wondered how a turntable works?
How does it take those grooves on a vinyl record and turn them into the music we hear?
It’s a fascinating process that has been refined over the years, but the basic parts have remained the same.
From the stylus to the turntable, each component plays a crucial role in producing the sound we love.
In this article, we’ll take a closer look at how a turntable works and explore the science behind it.
So sit back, relax, and let’s dive into the world of vinyl records and turntables.
How Does A Turntable Work
At its core, a turntable is an electromagnetic device that converts sound vibrations into electrical signals. When a vinyl record spins on the turntable, it creates sound vibrations that are picked up by the stylus, also known as the needle.
The stylus is made of a hard material, usually diamond, and is shaped like a cone. It sits at the end of the tonearm, which is mounted to the side of the turntable and sits parallel to the record. As the record spins beneath it, the stylus rides around the spiraling grooves of the disk, picking up the vibrations which are ultimately turned back into sound.
The vibrations travel along a flexible metal strip and wires housed in the tonearm to the cartridge at the end of the tonearm. The cartridge receives the vibrations, which are converted to electrical signals through a coil in a magnetic field. The electric signals are carried along wires to the amplifier which enhances the power of the signal. Finally, the signals are converted back to sounds that come out through the speakers.
It’s important that the turntable spins at just the right speed because a turntable that spins too fast makes a sound resembling The Chipmunks, and a turntable that spins too slowly makes a sound resembling Eyore. Turntables use either a belt drive or direct drive system to spin the turntable.
A belt drive system uses a thin rubber belt looped over the motor and central axle of the turntable to spin it. A direct drive system uses gears to turn the table directly using an electric motor.
The Parts Of A Turntable
A turntable is made up of several intricate parts that work together to produce high-quality sound.
The plinth is the base of the turntable and holds all the electronic components that make it work. It can be made from materials like metal, wood or acrylic, and it also adds to the aesthetic appeal of the turntable.
The platter is the part of the turntable where the vinyl record sits, and it spins to produce sound. The slipmat, which is placed on top of the platter, prevents the record from slipping off and acts as a buffer to reduce vibrations that can interfere with sound quality. Platters can be made from various materials like aluminum, plastic, glass or acrylic, with acrylic being a popular choice due to its density and consistency in play speed.
The tonearm is mounted to the side of the turntable and supports the cartridge, which contains the stylus responsible for picking up vibrations from the record’s grooves. Tonearms can be either straight or s-shaped, with each having its own pros and cons. S-shaped tonearms distribute mass evenly on either side of the pivot point, but they can be heavier due to their longer length.
The cartridge receives the vibrations from the stylus and converts them into electrical signals through a coil in a magnetic field. The preamp then transposes these signals into volumes loud enough to hear through speakers.
The counterweight at the end of the tonearm needs to be set correctly to apply the proper amount of tracking force to ensure accurate tracking of the record. Most tonearms pivot from a full bearing, but there is a growing trend towards using uni-pivot designs that reduce bearing friction by minimizing contact area between moving surfaces.
How The Stylus Reads The Grooves
The stylus reads the grooves on the vinyl record by following the undulations in the spiral groove. The stylus is mounted at the end of a cantilever, which is attached to the cartridge. As the record spins, the stylus moves up and down along the groove, tracing the wavy path of the recording.
The stylus is made of a hard material, usually diamond, which is shaped like a cone. It sits in the groove of the record and moves along with it as it spins. The tiny movements of the stylus are what create the electrical signals that are sent to the amplifier to be turned back into sound.
The cantilever acts as a mechanical amplifier, magnifying the tiny movements of the stylus and transmitting them to the cartridge. The cartridge contains either a piezoelectric crystal or an electromagnetic coil that converts these mechanical vibrations into electrical signals.
The piezoelectric crystal generates an electric current when it is compressed or stretched, while the electromagnetic coil generates a current when it moves through a magnetic field. Both methods result in an electrical signal that is fed into the amplifier.
It’s important that the stylus is properly aligned with the groove so that it can accurately track the undulations in the recording. A misaligned stylus can cause distortion and damage to both the record and the stylus itself.
The Role Of The Tonearm And Cartridge
The tonearm and cartridge are two of the most important components of a turntable. The tonearm is responsible for positioning the stylus over the record and tracking the sound vibrations as they enter through the stylus. It consists of two pieces – an arm base and a headshell at one end. The headshell holds the cartridge, which contains the needle responsible for reading the modulations on the groove of the record.
The tonearm needs to be balanced so that the weight of the stylus and cartridge is evenly distributed. This is done by adjusting counterweights on the arm’s back end. The physical design of a tonearm varies by model, but it usually consists of a metal or plastic arm that holds the cartridge. Tonearms can be made from various materials, such as carbon fiber, plastic, aluminum alloy, or wood.
The cartridge receives the vibrations from the stylus, which are then converted to electrical signals through a coil in a magnetic field. The electrical signals are carried along wires to the amplifier, which enhances their power. Finally, the signals are converted back to sounds that come out through the speakers.
Turntable cartridges come in different types, including moving magnet (MM) cartridges and moving coil (MC) cartridges. MM cartridges are more common and offer a warm sound with good bass response. MC cartridges are more expensive and offer better detail and clarity.
How The Turntable Motor Works
The motor is the heart of the turntable, responsible for spinning the platter at a constant speed. In a direct drive turntable, the motor is located directly under the center of the platter and is connected to it directly. This means that there is no belt to wear out or break, making them ideal for DJs who need a quick start-up time and the ability to scratch records.
Direct drive turntables have a high torque motor which means that the platter speed is less susceptible to outside forces such as the stylus or hand. This also means that the platter will accelerate to its proper speed faster, reducing distortion when the record begins to play. Some direct drive turntables use the platter itself as the rotor in the turntable’s synchronous motor, meaning that there is no motor per se in the turntable. The platter is entirely driven by the magnetic field induced by the turntable’s stator.
On the other hand, direct drive turntables may suffer from vibration due to the motor, which can affect sound quality. To combat this, shock-absorbing material has been used to cut back on vibrations. In addition, slipmats are used to reduce friction between the spinning platter and record, which helps isolate the record from motor vibrations that would be picked up by the stylus.
Turntables for DJ use also include a pitch control, which allows for fine tuning to the correct speed used in conjunction with a strobe light. This technique is known as beatmatching and assists DJs in musical performances. Some manufacturers have even included other electronic controls such as reverse and “nudge.”
Understanding The Importance Of Platter Size And Weight
When it comes to turntables, platter size and weight play a crucial role in the overall performance of the device. The platter is the circular platform on which the vinyl record sits and spins. The size and weight of the platter can affect the speed stability, noise floor, and resonance of the turntable.
There are varying opinions on what makes for the best platter size and weight. Some argue that a heavier platter is more desirable for speed stability. Once the platter has reached the correct speed, there is a degree of “flywheel” effect, which means the motor switches over to regulating the speed rather than applying constant accelerative force. This is an anathema to others who believe that such a process means that the platter is being encouraged to sit around the desired speed and not exactly at the desired speed.
A light platter can be coupled and controlled directly by the motor which means that it will spin at exactly what speed you tell it to. However, some argue that this leaves the platter more susceptible to interference from the motor.
When it comes to noise, heavy platter proponents argue that a thicker platter with extra mass is less likely to transmit any form of noise from the bearing. Lightweight enthusiasts counter that smaller and lighter platters don’t need such a massive bearing that in turn can be smaller and more efficient.
Ultimately, finding the right platter size and weight for your turntable depends on personal preference and experimentation. It’s important to consider factors such as speed stability, noise floor, and resonance when making your decision.
The Impact Of Anti-Skate And Tracking Force
When it comes to playing vinyl records on a turntable, the impact of anti-skate and tracking force cannot be overstated. These two factors play a crucial role in ensuring the optimal sound quality of your records.
Tracking force refers to the amount of pressure that the stylus applies to the record while playing. It is important to set the tracking force according to the instructions on the cartridge for your turntable, as exact recommendations may vary slightly. The right tracking force ensures that the stylus moves smoothly across the grooves of the record, picking up all the sound vibrations and translating them into electrical signals.
However, even with the correct tracking force, skating force can cause issues. Skating force is a tertiary motion that occurs when the tonearm veers towards the center of the record. This can cause the stylus to skip or jump around, adding wear and tear on the grooves themselves. This is where anti-skate comes in.
Anti-skate is a feature on many turntables that prevents tracking issues when listening to a record. It applies a countering force to the tonearm when it is in motion, maintaining equal force on both sides of the stylus to keep it balanced within a typical groove. This balance is not natural and has to be created by the anti-skate control. If left unchecked, skating force can cause uneven wear on both stylus faces that are in contact with the groove wall and affect stereo balance.
Properly setting anti-skate ensures that your records play smoothly and reduces wear and tear on both your records and stylus. It also helps maintain audio balance between left and right channels, reducing distortion and improving sound quality.
In conclusion, anti-skate and tracking force work together to ensure optimal sound quality when playing vinyl records on a turntable. It’s important to set both correctly according to manufacturer’s instructions to prevent tracking issues, reduce wear and tear on your records and stylus, and improve overall sound quality.
