How Ortofon Hi-Fi Cartridges Work

Moving Magnet and Moving Coil pick-up cartridges are designed to read the tiny modulations in a vinyl record's groove, and convert the mechanical motion to an electrical impulse which can be amplified through a hi-fi system to music that we can hear and enjoy. It is a critical component to understand when trying to get the best from a turntable-based hi-fi system.

For detailed advice on cartridge set-up, visit our Cartridge Installation page. Here, we explain how pick-up cartridges work and what to look out for before you buy - particularly when considering an Ortofon cartridge.

The Principle:

Record Cutter Detail
Vinyl records are originally cut by a machine which effectively acts like a hi-fi cartridge in reverse; putting recorded music into a record, rather than extracting information from it. Here, our simplified animation helps to explain the process better...

This basic animation shows a cutter head controlled by a Left and Right (stereo) audio signal. The original analogue recording provided from a studio therefore directly impacts on how the record groove is cut. The effect of this can be shown when we take a very high-resolution photo of the resultant record groove, like the one shown below...

Record Groove
Image taken from Vinyl Factory.
Cartridge manufacturers therefore design products which can track these movements and modulations in a record wall and convert the mechanical energy they generate to an electrical impulse. To achieve this, Ortofon include these fundamental parts in each of their cartridges – regardless of price:

1. A diamond
2. A rigid cantilever
3. Magnets
4. Wire coils
5. Suspension

Diamond Stylus Profiles:

Cartridge Stylus Profiles
Diamond is chosen as the material of choice for reading a record groove because it is an incredibly hard material that will not degrade considering the huge forces that are applied to it when playing back a record. When set-up correctly, it will also not rapidly degrade a record groove.

Because of the costs of sourcing diamond as a material, some more affordable cartridges have tipped diamonds – where the diamond is mounted onto another hard material, which in turn is mounted to the cantilever. More premium designs are classed as ‘Nude’ because they are a single piece of diamond connected directly to the cantilever. Using a one-piece diamond has obvious benefits for optimum transmission of the music signal.

How the diamond is cut to read the record groove strongly influences the eventual musical performance of a pick-up cartridge. Broadly speaking, there are three types of stylus profiles in wide use today. At the higher-end there are more unique ‘cuts’, but here we will only mention the most common.

Above are four drawings of a record groove. Slide a. shows the profile of an original cutting stylus – obviously this is what dictates the level of detail in a record groove. Slide b. shows a spherical stylus in the groove. Spherical styli are the most common and most basic profile; they are easier to manufacture, so they are more affordable, but they pick up little information from the record wall and also put high amounts of pressure on localised parts of the groove. Slide c. shows an Elliptical stylus in the groove. Elliptical styli have their sides polished so they read more of the groove, but are still at the more affordable end of the price spectrum. Finally, slide d. shows a Fine-Line stylus in the record groove. Fine-Line styli are often found in more premium designs and boast an optimized polished profile, which allows for far greater contact than both Spherical and Elliptical designs.

Moving Magnet (MM) vs. Moving Coil (MC):

There are, broadly speaking, two types of pick-up cartridge in common use today. Typically, moving magnet cartridges are at the more affordable end of the price spectrum because of the extra level of micro-engineering involved in moving coil manufacturing. The main differences of each are detailed below...

Moving Magnet Cartridge Internals
In a moving magnet cartridge the diamond is attached a rigid cantilever, which is controlled in its movements by a suspension system. The movement which the cantilever system creates when reading a record causes a magnet – attached internally to the cantilever – to move. This movement from the magnet interacts with coils of very fine wire inside of the main cartridge body, which each contain around 3,000 windings. The result of this varying magnetic field is an electrical current, which represents the original music signal.

 

Moving Coil Cartridge Internals
The moving system in a moving coil cartridge is lighter, which allows for an easier, more fluid movement of the cartridge’s components. The principle which MC cartridges use is the same; they just reverse to essential components. Here, the coil (of typically 10-30 windings) is attached to the cantilever system, and the magnet sits within the main body. However, the electrical generation is the same – the only difference here is that because the moving coil has less mass, the output is typically lower, which is why phono stages have separate moving magnet and moving coil settings. Because of this more delicate and complex construction, moving coil styli are non-replaceable, unlike moving magnet designs.

Understanding the Ortofon Range:

Ortofon are one of the last remaining dedicated cartridge companies. As a result, they boast a wide range of cartridges suited to a variety of budgets and music preferences. The OM and 2M series represent Ortofon’s moving magnet models, though they offer replacement styli for a wide variety of older designs. Ortofon’s moving coil models range from the more affordable Quintet series and the premium Cadenza range up to the high-end, exclusive models - such as the flagship MC Anna.

All the models in Ortofon’s 2M, Quintet and Cadenza ranges are distinguished by their colour. The colour represents not only each models' price position in the range, but also its unique sonic characteristics. Below, the typical sound performance for each colour is described, in price-ascending order:

RED
Good harmonic sound from a good value-for-money cartridge. The Red models always represent the entry-level cartridge in a range.

BLUE
More precise sound than a Red cartridge; Blue cartridges tend to have a higher frequency bandwidth for a more ‘direct’ sound.

BRONZE
Bronze cartridges tend to have a more damped and romantic sound, suiting them particularly well to classical compositions.

BLACK
Black cartridges always represent the top of a range, and as a result they offer the best of everything. They read a lot more of the groove, offering a more balanced and ‘truer’ musical performance than any other competitor product. They are strictly true to Ortofon's mantra of "Accuracy in Sound".