maPlatine.com glossary

To help you choose your turntable, Hi-Fi cartridge, phono preamp and accessories, maPlatine.com has compiled a new glossary. Feel free to consult it for help with the technical terms of the Hi-Fi world.

33 RPM: This is the most commonly used name of 12 and 10 inch vinyl records. It is played on a turntable at a minimum speed of 33.33 revolutions per minute.  This format was first marketed in 1949.

 

45 RPM: These vinyl microgroove records are usually 7 inches (17cm) in diameter, although there are also 'Maxi Single' 45 rpm records that have a diameter of 12 inches (30 cm). This format was first marketed in 1949. As a general rule, 45 rpm records must be played at a speed of 45 revolutions per minute.

 

78 RPM: These vinyl records have a diameter of 10 inches (25 cm) and were marketed between 1925 and 1960. Originally designed in Shellac, a substance produced by the secretions of an insect living in Asia and combined with other ingredients, such as slate, wax, cotton, etc. In 1960, with the surge of 33 and 45 rpm records, this format became less popular.

 

A

ANTISKATING: This term refers to the correction of the centripetal force applied to the cartridge, which thrusts the stylus towards the centre of the record during playback. Antiskating compensates for this force and prevents the early wear of the wall of the record grooves as well as the inner side of the stylus during playback. It must be applied according to the specifications of the manufacturers of the cartridge and of the tonearm with which it is associated.

Over the years, manufacturers have developed a number of innovative technical solutions. However, a fairly simple method to implement has become the most widespread, namely a brass rod with a hoop that supports a nylon thread that connects a small weight to the turntable tonearm. This solution is extremely effective if it is properly designed and very easy to use.

There are other means of correcting the centripetal force, such as magnetic repulsion, a coil spring system that can be adjusted with a thumb wheel.

Note that some high end unipivot tonearms do not use this correction as antiskating is provided by the cable through the tonearm of the turntable.

 

DRIVE SPINDLE: spindle around which the platter is placed.

AZIMUTH (OR TILT): It is the angle between the surface of the record and the vertical axis of the Hi-fi cartridge. It can be referred to as the tilt of the cartridge. The azimuth must be perfectly horizontal to prevent any unbalance between the two channels, additional distortion and further groove wear.

Explanatory diagram of azimut

B

BANDWIDTH: The bandwidth is a frequency range that the system can process. It is expressed as Hz and the first digit indicates the minimum response for bass and the second digit indicates the maximum for treble.

BERILIUM: Very lightweight, white, metallic element that is both fragile and extremely resilient (6 times more than aluminium).

MOVING COILS: Moving coil cartridges (or MC) include two coils that are attached directly to the cantilever, as opposed to MM (Moving Magnet) cartridges, where the magnet is attached to the cantilever. Therefore, the two coils need to be much lighter that in MC cartridges, which generates a better response and a much finer sound quality. The design of moving coil cartridges is therefore more accurate, which explains the price difference compared to moving magnet cartridges (MM). Still, these cartridges are very popular with audiophiles because of their performance levels, which are both tangible and subjective.

BORON: Chemical element classified as a metalloid, extract from borax or kernite. It is used to make high end cantilevers.  Boron has highly advantageous mechanical properties, including a score of 9.5 on the Mohs hardness scale (by way of comparison, aluminium has a score of 3 and diamond a score of 10).

PHONO CARTRIDGE CONNECTION TERMINALS:  

To mount a Hi-Fi cartridge four wires of the turntable tonearm have to be connected to the associated terminals on the cartridge. 

They can be arranged as follows:

'+' left channel: WHITE

'-' left earth: BLUE

'+' right channel: RED

'-' right earth: GREEN

 

Connection terminals of a phono cartridge

TONEARM: Part of the turntable that supports the Hi-Fi cartridge.

LINEAR TRACKING TONEARM: Instead of moving in a curve during playback, it moves in a straight line (tangentially to the microgrooves). The operating principle, very simple in theory and fully in line with the record's original recording, is actually complex. That's why nowadays, only very few brands make them.

 

C

CANTILEVER: A cartridge is made up of three components: stylus, cantilever and suspension. The cantilever is the small arm that is attached to the phono cartridge and supports the stylus. Its role is to vibrate in exact sympathy with the stylus in the record groove, up to the moving part of the cartridge. It can be made of either beryllium, boron (Ortofon Cadenza Black), ruby (Ortofon Cadenza Blue) and sometimes diamond (Dynavector). Many cartridges however, including high end versions, have an aluminium cantilever. It usually has a cylindrical profile, though it can sometimes be conical.

 

Position of a cantilever

 

CAPACITY: Accumulation of electrostatic charges between two conductors that are isolated from one another. Its unit of measurement is the microfarad.

CARTRIDGE: Part used to play a record. It converts the mechanical oscillations of the stylus to a low voltage electric signal. 

 

MOVING MAGNET CARTRIDGE: The cantilever of MM cartridges is completed with a pair of small permanent magnets that will oscillate close to a pair of coils (stationary) inside the cartridge. As the stylus traces the groove, the magnets start vibrating, creating an electric current inside the coils that is similar to the audio signal recorded on the record.

 

LOAD: This technical term refers to the electrical characteristics of the phono cartridge. It covers the impedance of the cartridge, its capacity, etc. In fact, these parameters are used to determine the choice of preamplification stage in order to obtain the best sound quality.

Now going further into the technical details, a cartridge can be compared with an RLC circuit (resistor, coil, condenser), which typically reacts like a resonant filter. Namely, the filter boosts some frequencies and reduces others, and acts so that the Hi-Fi cartridge delivers the most linear frequency response possible.

 

COMPLIANCE: As opposed to stiffness, compliance is the property by which a flexible material will bend without breaking. All Hi-Fi cartridges are fitted with a suspension, so the compliance value is of particular importance. A phono cartridge with a high compliance will work to full potential with a lightweight tonearm and, conversely, a cartridge with a low compliance will perform best with a heavy tonearm. Compliance can be used to measure the resonance frequency of a tonearm if we know the mass of the cartridge and tonearm. The best results are obtained for frequencies between 9 and 13 Hz.

 

CONICAL: Some stylus tips have a conical profile, which improves the contact surface between the diamond and the record's groove. Other styli have a spherical design that are cheaper to produce and therefore more widespread on the market.

SUB PLATTERThe sub platter is the part that supports the drive spindle well.

COUNTERWEIGHT: Tonearm counterweight. It adjusts the tracking force applied to the cartridge stylus and must therefore be produced with great accuracy.

PLATTER MAT: A platter mat must be used with all alloy, glass and MDF platters. It wards off resonance from the record. Mats can be made of synthetic rubber, felt, cork, leather, etc. The mat's surface must be sufficiently adhesive so that the record won't slip.

D

DAMPER: A damper reduces vibration induced by a vibrating element.

CROSSTALK: Crosstalk occurs when the right channel signal overlaps the left channel signal on a cartridge, and vice versa. Namely, traces of the first signal remain audible on playback of the second signal. This is also referred to as 'noise' and this phenomenon is often caused by electromagnetic inductions.

DISTORTION: Deformation of the signal caused by poor-quality or defective elements leading to imprecise, distorted and sometimes unpleasant sound quality.

DYNAMIC RANGE: Difference (in decibels) between the maximum and minimum level of a signal. By extension, the dynamic range of a medium is the gap between the maximum level that it can record and its intrinsic noise level.

E

SKIN EFFECT: Also known as the Kelvin effect, it refers to an electromagnetic phenomenon that affects all alternating currents. When the frequency is high, the current tends to circulate towards the surface of a conductor. The further it moves away from the conductor's outer edge, the more the current density decreases, increasing the conductor's resistance as a result. This means that the current does not circulate evenly through the conductor.

MEMORY EFFECT: A signal going through a conductor charges the conductor's insulator with static electricity. It is then transferred to the following signal. Some insulators are not very sensitive to this effect: air, porcelain, Teflon, and others.

ELLIPTICAL: The shape of the stylus can also be elliptical, i.e. the tip is initially cut to a spherical shape and cut twice. The two cuts increase the vertical contact surface and reduce the forward/backward contact area between the tip and the record's groove.  The elliptical profile is an upgrade of the spherical profile that significantly increases the frequency response. The phase is therefore more stable and distortion is generally reduced, in particular at the end of the record.

 

CHANNEL BALANCE: This term refers to the a cartridge's ability to identically reproduce a signal on both channels. This difference can be measured in decibels (dB), if it is zero, playback of a monophonic record will generate an identical output level for each channel. Therefore, a difference of 0dB between both channels is ideal.  This imbalance can be caused by several factors that are unrelated to the cartridge. From a mechanical standpoint, this defect can be caused by a poorly adjusted azimuth, an incorrect alignment between the cartridge and headshell and even between the headshell and tonearm. Antiskating adjustment is also a key factor.

From an electrical standpoint, balance problems can be caused by a number of factors, such as the connector cables, the setup of the stereo preamp, the power amp, the loudspeaker filters, as well as the acoustics in the room where the system is used.

 

Phono cartrdige on a vinyl record

 

TONAL BALANCE: Balance between the 3 main ranges (bass, mid-range and treble).

STYLUS/CANTILEVER ASSEMBLY: Element that is not attached to the body of some MM cartridges. It includes the cantilever and the moving part. With this design, the stylus is field-replaceable and does not require removing the phono cartridge of a turntable. MC cartridges do not have user-replaceable stylus assemblies.

F

TRACKING FORCE: Force applied to the phono cartridge on a vertical plane, perpendicular to the record. Its intensity is determined by the counterweight. For best sound quality, the cartridge must stay permanently in contact with the groove walls so that all the information recorded will be processed. Manufacturers apply an optimum tracking force to each cartridge, measured in grams. This value is often provided as a range with a difference between 2 and 4 grams. The cartridge will wear much sooner if the tracking force is too low, because if the stylus bounces out of the groove, it will damage the information recorded on the groove.

G

GAIN: In the music world, gain is also known as amplification, i.e. the capacity of your Hi-Fi system to increase the amplitude of the signal. Gain is usually measured by calculating the ratio of the input signal and the output signal and its unit of measurement is the decibel.

I

IMPEDANCE: Electronic circuits have the ability to reduce their specific electric current. This measurement is known as the impedance of the circuit. An electronic circuit has an 'input' and 'output' impedance. Input impedance refers to what is perceived by any source connected to this circuit. As opposed to the output impedance, which reflects the impedance applied to each device connected to the output. Best sound quality will be achieved if the input impedance of a phono preamp and the output impedance of a Hi-Fi cartridge are in line. Otherwise, the connection between the two devices will act as a filter on the signal, which will therefore only be communicated partially. As a guideline, the input impedance of a phono preamp (cartridge load impedance) must be 10 times greater that the output voltage of a phono cartridge.

L

ARM LIFTER: mechanism used for automatically or manually lifting the tonearm to which the cartridge is attached.

LP: Acronym for Long Play, used for 33 rpm 12-inch vinyl records. It was initially unveiled by Columbia in 1948 and its use became more widespread in the record industry in the mid 50's. LPs were adapted for stereo playback in 1958, and this format is still a benchmark to this day. 

M

MC (MOVING COIL): Moving coil Hi-Fi cartridges are high-tech devices and are therefore a lot more complex to assemble, and as such, more expensive. This technology is used with high end Hi-Fi cartridges. They have a low output level, generally below 0.8 mV and require a suitable phono preamp or transformer. However, some MC cartridges are referred to as 'high output', meaning that the design uses more wire on the coil. This process allows them to have a high output level (generally above 2mV) and therefore to be compatible with all standard phono preamp models. Important: the stylus is not interchangeable.

MDF: Medium density fibreboard

MM (MOVING MAGNET): Hi-Fi moving magnet cartridges are the most common on the market and the simplest to make, and therefore the cheapest. Their stylus is interchangeable, their output level is usually over 2mV, making them compatible with all commercially available phono preamps.

MONO (OR MONAURAL): One audio signal transmission channel is required to reproduce a monophonic recording. Note that all microgroove records released before 1960 are almost entirely recorded in mono. Likewise, all 78 rpm records are mono.

 

MU-METAL (µ-METAL): This alloy is a combination of nickel and iron. Its advantage lies in its electromagnetic capabilities. It is in fact extremely advantageous when used for shielding, in particular in an MC cartridge, where it can isolate the magnetic fields generated by the two moving coils. Mu-metal is often used to shield electric transformers processing low signals, as is the case with the input stage of some preamps.

 

N

NEODYMIUM: This chemical element is used for the production of permanent magnets with a high magnetic intensity. It is quite prevalent in the high-fidelity industry, specifically when small dimensions and a powerful magnetic field need to be combined.

 

NUDE: A nude stylus means that the diamond bonded to the cantilever hole is made up of one piece.  Contrary to bonded mounting, for which the stylus is not made of a single piece.

 

Diagram of a phono cartridge

 

O

OFC (OXYGEN FREE COPPER): 5N oxygen free copper (99.999% oxygen free copper) 7N (99.99999% oxygen free copper) or 9N (99.9999999% oxygen free copper)

OVERHANG: it is a setting to determine how far a cartridge protrudes over the tonearm of a turntable. This setting will perfectly align the cartridge with the groove tangent.

P

RECORD CLAMP: Its role is to hold the record completely flat on the platter.

PLATTER: Part of your turntable that supports the record. It can be made of different materials: MDF, aluminium, steel, acrylic, and others.

WOW: deformation of the sound induced by speed fluctuations between the recording and the playback on your turntable.

PIVOT: Mechanism that moves the tonearm horizontally and vertically while minimising stress and friction.

 

PHONO PREAMP: The role of a phono preamp is to be able to process sound levels with very low amplitudes. This means that it enables a signal coming from a phono cartridge to be boosted, while applying as little distortion as possible for the final sound quality.

Ideally, you should opt for a phono preamp in its own housing rather than using the phono input of a built-in amp because the sound quality will be significantly improved.

 

The inside of a preamplifier

 

R

RADIUS: The radius of a phono cartridge stylus measures units of the order of a micrometer (i.e. a thousand times smaller than a millimetre!). For specific and complex stylus profiles, measuring the radius is not necessary or in any case, it would be too complex to be easily usable.

RCA: Interconnect or phono cable that uses standard cables called RCA: the central point is the signal and the outer edge is the ground wire.

FREQUENCY RESPONSE: Measurement by which the sound quality of a Hi-Fi cartridge reading a specific sound signal can be measured. The signal starts to transmit 1 Hz, then the signal scans all audible frequencies from bass to treble. The frequency response is simply the result of this experiment, often presented in chart form showing the amplitude in volt according to the frequency in hertz, and it should be as flat as possible.

RESISTANCE: A physical principle that reduces the passage of electric current. Also a component that reduces heat by the Joule effect.

RIAA: This acronym stands for Recording Industry Association of America. Il fait référence à une organisation interprofessionnelle ayant pour objectif de défendre les intérêts de l’industrie du <stro