THE PICKUP – AN AUDIO MECHANICAL WONDER

The delicious analogue vinyl sound starts and ends with a good pickup. But how does this little machine really work, and which type fits your needs exactly? We take you on a journey in behind the diamond needle.

The pickup is the unit that captures/reads the various variations of the actual track on the vinyl record and then converts these vibrations into an audio signal that can be amplified and transmitted through your speakers. There are many types of pickups for turntables, all with their own unique characteristics and in all price ranges.

A pickup is a so-called “mechanical transducer”, a bit like a microphone. It converts motion energy into electrical energy, and it colors the sound significantly more than conventional electronics. The extreme fine mechanics are easily influenced by both the precision of the mechanics themselves and external influences.

The needle in a pickup moves over the vinyl material at incredible speeds. It can be subjected to g-forces (gravity acceleration) of up to 100 g and move at a speed of over 100 kilometers per hour. By comparison, the F-16 fighter plane can perform around 9g, and a highly trained pilot risks fading at 7g. Then it is easy to understand that the pickup must be of very high mechanical quality to be able to read the tracks perfectly.

Multiple pickup types for multiple needs

The most commonly used pickup types are Moving Magnet and Moving Coil, also called MM and MC. There are also other more unusual types that we will not go into further detail in this article.

The choice of pickup is often a matter of quality, price, and how the pickup in question matches the turntable, tonearm and music system to which it is connected. In this article we give you some basic knowledge about the different types of pickups and the technology around them.

The disc and the tracks

The engraving head cuts the grooves from the outer edge and into a spiral towards the center of the disc. This is the lacquer master that is then sent for reproduction, where it is sprayed with silver nitrate that fills all the disc tracks. It is then chemically treated to create a negative metal release, a so-called “metal pestle”. This is used to press the vinyl into finished discs. When making a vinyl sheet, you start by cutting a master that is either a copper sheet (Direct Metal Master – DMM) or a “lacquer master” which is an aluminum sheet with an applied surface of vinyl acetate – which is basically reminiscent of nail polish. In this varnish coating, the traces are cut by the engraving machine, a so-called “cutting lathe”.

Vinyl mastering is a very difficult and expensive process and it takes many years of experience to do it properly. This is one of the reasons that vinyl records usually cost a little more and often have large quality differences depending on where they are mastered. And now – back to the pickup!

The structure of the pickup

The pickup consists of a small diamond needle mounted on a small tube, called the needle tube or cantilever. Behind this tube is a magnet or coil mounted which is set in motion as the needle follows the disc grooves. The movement creates a current/voltage in the magnetic field inside the pickup, and it is this variation in the current/voltage that we can amplify and hear as music in our speakers.

There are normally three types of pickups: Moving Magnet, Moving Coil and high output Moving Coil.

MM – Moving Magnet

The Moving Magnet pickup is the most widely used pickup type on today’s turntables because it is cheap to make and delivers fine performance at its price. By default, it is usually MM pickups that come with a turntable.

Moving Magnet is, as its name implies, an electrical system, where a magnet has been mounted on the end of the “cantilever”, ie. it touches the diamond needle which is mounted on the other end. This magnet moves between two pairs of coils, and together they make these a very small electromagnetic generator. When the needle follows the tracks on the disc, the magnet moves similarly between the coils and generates in the coils a small current/voltage that reflects the music of the tracks.

The advantage of this design is that it is relatively simple and inexpensive to produce and that the needle and cantilever can be replaced when worn off.

MC – Moving Coil

Moving Coil pickups are usually something you find on slightly more expensive and better turntables, or they are sold separately for you to upgrade your turntable. MCs are available in many price ranges but are usually slightly higher than the MM models. This is because they are much more difficult and expensive to manufacture. In return, they also offer a sound quality that can be significantly better than the one you get from a typical MM pickup.

Some sharp-sighted readers have certainly figured out that the Moving Coil pickup consists of an electrical system where (compared to the Moving Magnet type) it is the coils that move instead of the magnet.

In an MC pickup, the coils have been placed directly on the cantilever, and thus they are located in the magnetic gap where they are in a very powerful magnetic field and vibrate after the vibrations of the music.

The coils are extremely small and made with very thin wires, so it is quite obvious that it is quite difficult to manufacture MC pickups correctly. Therefore, they are almost always handmade, such as at Ortofon. They also often use finer materials compared to MM, which of course also leads to the fact that they cost more to manufacture.

High-output Moving Coil

There are also high-output MC pickups. Here is room for some more windings on the coil and use stronger magnets. This way you can get a higher output signal from the pickup, so you can connect it just like an MM model. This is an attempt to take the best of both worlds.

You get many qualities from the MC design, but with a high output, so the requirements for the RIAA preamplifier are not as high as for a genuine MC pickup. High-output MC is actually a pretty elegant compromise, but it does not give the exact same precision as the pure MC types, mainly because of the more windings and the higher weight this leads to.

How long can my diamond needle last?

When you play your discs, the needle cannot be saved. A diamond needle normally lasts about 1,000 hours without audible deterioration if you are good at keeping the needle and discs free of dust and dirt, and if the pickup and arm are set correctly. This corresponds to about one disc per day for about three years.

For both sound and financial reasons, it is a very good idea to stick to new and fresh pickups. When it comes to MM pickups, you usually only need to buy a new stylus, then it is like new again, but if you use the MC you have to replace the entire pickup. It is difficult to give a concrete answer on when a pickup is too old or has become too worn as it varies between different brands. A good rule of thumb is that, whether you play one plate a day or one a year, you should consider saving together for a new pickup or new needle as it approaches three years.

Which pickup should I choose?

If you just want to listen to your old plates in good quality without getting too complicated, an MM pickup is definitely recommended. They are available in all grades and are very easy to deal with. Some models can even be upgraded with a better needle as it begins to wear. A good start, for example, may be a pickup from Ortofon’s 2M series that contains some of the world’s finest MM pickups.

If you are used to an MC pickup you are probably already used to mounting and adjusting.

REMEMBER: A pickup is never better than the turntable it sits on. Unless the turntable does not create good working conditions for the pickup, even the most expensive pickup can perform poorly. Therefore, a better turntable with a cheaper pickup is better than an expensive pickup on a cheap turntable. This way you can also upgrade the turntable later.

However, a good pickup is always a good component to upgrade if you already have a turntable. This is where the sound begins, so this improvement can be useful all the way to your ears.

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