The earliest recording device was the phonograph, invented by Edison in 1877, in which an analogue wave was stored mechanically. A person’s voice was recorded as the person spoke into a horn which had a diaphragm at the back. As the voice vibrated the diaphragm, this in turn caused the movement of a needle against a tinfoil cylinder. A groove was thus created by the needle on the tinfoil. The process is reversed when the tinfoil cylinder rotates: the needle vibrates against the groove and the vibrations are picked up by the diaphragm and transmitted to the air in the same manner to recreate the original sounds.
Based on this same principle, gramophone records are flat discs used for recording, first patented by Emile Berliner in the year 1887. This innovation allowed mass production of the records and replaced the cylinder with grooves. These gramophone records, also called vinyl records, are analogue audio storage systems. During recording, vocal cords cause the surrounding air to vibrate and these vibrations are inscribed as grooves on the recording disc. When a disc is played, a needle or stylus in the tonearm of the phonograph moves and vibrates on the inscribed grooves and the vibrations are converted into electrical signals. These signals are amplified and the same sounds are recreated by the loudspeaker.
The Role of the Cartridge and Stylus
In the modern phonograph, the vibrations of the needle or stylus are deciphered and amplified electrically to recreate high-fidelity sounds recorded on the disc. In these gadgets, the magnetic cartridge with a stylus is the transducer. The stylus moves within the spiral grooves as the disc rotates and the vibrations of the stylus convert into electrical signals that are amplified and recreated as original sounds by the speaker systems.
Cartridges, also called pickups, are the contraptions to which a stylus is attached. In earlier times, the crystal or ceramic cartridges were used with a stylus, also called a needle. The stylus, once sapphire or diamond, rides the groove as the disc rotates while playing. The magnetic cartridges introduced later replaced the ceramic cartridges and are a popular product now. Several types of magnetic cartridges are also available such as the moving coil and moving magnet.
Generally, when the stylus is replaced, the type of stylus required depends upon the type of cartridge one has. Knowing the basic features of both cartridges and styli enables the shopper to make an informed choice while buying, especially if buying online. eBay has a vast array of cartridges and styli and armed with the relevant details, online shopping is a pleasant and productive experience.
The Ideal Cartridge-Stylus Mechanism
The mechanical function of the cartridge is to hold the stylus and place it within the groove with just the right pressure. The ideal setup involves steady movement of the stylus as the disc spins, irrespective of changing frequency signals. Despite jolts because of fluctuating frequencies or pauses in groove modulations, the stylus should retain its central position and adapt easily to the right vibrations as the music stops and starts.
Types of Cartridge Mounts
Selecting the right replacement pickup cartridge compatible with the turntable tonearm mount is important for peak performance of the turntable. Mismatch of the cartridge and the tonearm can result in impaired track performance and unwanted resonances while the music plays out.
Standard 12-mm Mount
The 13-mm (1/2-inch) standard mount is a common mount and has been the standard for many manufacturers. The cartridge rests under a flat headshell and is attached to the tonearm using two screws placed 12.7 mm (half an inch) apart. Four wires on the mount attach the cartridge with the mount using spring clips.
Also called the T4P, the P-Mount is a plug-in style, compatible with turntables that have the T4P symbol on them. A single screw through the side fixes the cartridge to the tonearm even as the cartridge plugs into the mount.
Convertible or Universal Mount
A versatile mount, the universal phono cartridge mount, can be adapted to fit both standard mount and the P-Mount tonearm assemblies. The design makes provision for using two screws 12.7 mm apart with four spring clip slots for the four tonearm wires, which is the standard mount design and the plug-in, single-side screw attachment design of the P-Mount as well.
This is generally found in the high-end DJ applications in which precision is very much needed. Available with bayonet-style tonearm assemblies, the built-in integrated phono cartridge mount ensures perfect alignment as there is no additional mounting hardware.
Phono Cartridge Types
Cartridges and styli for turntables are available as piezoelectric pickups using ceramics and crystals as styli, notable among them being sapphire, diamonds, and the exotic metal osmium. While the osmium styli wear out easily, sapphire tends to damage the grooves on both vinyl and shellac discs and are thus unsuitable in the long run. A diamond stylus, though expensive as compared to the others, has longer life and will not damage the discs, giving from 300 hours to 1000 hour of listening pleasure. Users must track the stylus tip for signs of wear, however, otherwise the quality of the gadget is affected and so are the records. Magnetic cartridges are the most effective solution, amongst which there are a couple for users to choose.
Inexpensive and the best, magnetic cartridges are either moving coil or moving magnet giving high fidelity sounds and does not affect the discs as these ride the grooves with just the right pressure.
Moving Magnet (MM Cartridges)
A cantilever with the stylus at one end has a magnet at the other end that moves in consonance with the stylus as it traces the audio signal on the groove. This magnet is surrounded by magnetic conductors as well as copper wires inside the moving magnet cartridge. The moving magnet creates a magnetic field in the conductors and the copper coils convert it into electric signals. The stylus in most moving magnet cartridges is replaceable.
Moving Coil (MC Cartridges)
In moving coil cartridges, fine coils are wound around the stylus cantilever and move within the field of a large permanent magnet within the cartridge body. This is a highly sensitive device that tracks the groove accurately but has low output levels. The output signals must be boosted using preamplifiers and step-up transformers to cancel noises and other disturbances.
London (Decca) Cartridges
The positive scanning used in a Decca cartridge is unique to this type of cartridge. Though it has neither a moving coil or a moving magnet, this cartridge delivers the best sound reproduction of all. An L-shaped cantilever, attached to a metal support, is magnetically activated by vertical and lateral magnetic poles and coil assemblies in close proximity, effectively reading the vertical and lateral motion of the stylus as it rides the groove. The stylus shaft has a small piece of soft iron and, being less than 1 mm away from the tip, the tiniest of movements of the stylus are recorded accurately.
Crystal Ceramic Cartridges
The principle behind crystal and ceramic cartridges, collectively called piezoelectric cartridges, is that some crystals, when bent, give off electrical signals. A crystal or ceramic embedded in the lever of the stylus head bends when the lever moves side to side and creates electric signals. Piezoelectric cartridges are found in some retro phonographs which are still popular as collector’s items.
How to Buy Phono Cartridges and Stylus on eBay
While phonographs are not much in use, music lovers who want to keep alive the magic of the bygone eras will avidly pursue all avenues to obtain the old gadgets, records, and other parts that one may need. Cartridges and styli are much-sought-after replaceable parts and eBay is one place where several types are easily available. To begin a search on eBay, typing the relevant keywords such as ‘phono cartridges’ delivers several listings. Another way of finding desired products, especially if one is looking for a specific model, is by typing in the brand name. This is especially true of electronic and electrical gadgets, as most would work best with OEM parts.
All sellers specify details about postage and shipping; nevertheless, shoppers would do well to ascertain the exact costs before purchase. For additional savings, look for items with free shipping. eBay offers numerous payment options, all safe and secure, so shoppers can confidently complete their online deals.
Music lovers hooked on to retro gadgets such as phonographs and gramophones will rejoice to find that cartridges and styli are easily available online. After determining the type of the cartridge mount on the gadget, one is ready to begin scouting for the cartridge, selecting from amongst the four types of mounts that are generally available: the standard 13-mm (1/2-inch) mount, the P-Mount, the universal mount, and the integrated mount. After determining the mount type, the shopper can opt for the different types of magnetic cartridges, Decca cartridges, or from the piezoelectric cartridges for retro phonographs and gramophones. The most widely used cartridges are moving coil (MC) or moving magnet (MM), and these are easily available from several manufacturers of international repute. Knowing the replacement part number, make and model is helpful in making the most accurate match when buying online. Since the ultimate performance of the gadget and the longevity of records depends a great deal on the cartridge and styli, one must choose these items with the utmost care.