Magnets are an essential component of electric guitar pickups. Without a magnet, there is no magnetic field, so no sound: it’s that simple. But how do these magnets affect the sound of microphones? We will analyze the different characteristics of Alnico and ceramic magnets used in electric guitar pickups.
A for Alnico, C for Ceramic 8
Most of the pickups we use are equipped with Alnico or ceramic magnets. Alnico is the acronym for the 3 main elements that make up this alloy: Aluminum, Nickel, Cobalt. They also contain a very small part of Copper and for some (6, 8 and 9) a little titanium. The different types of alnico are classified by grade (1, 2, 3, 4, 5, 6, 7, 8, 9). Historically, the magnets used in the manufacture of electric guitar pickups are the Alnico 2, 3 and 5. Subsequently the Alnico 4 and 8 were integrated and very recently the Alnico 6 and 9 appeared.
Each grade of Alnico has specific magnetic properties and its own sonic character.
The output level of a microphone depends on several parameters, in large part, the magnetic force of the magnet. This is measured in Gauss and varies according to the grade of the magnet and its size.
Vintage type Alnicos : 2, 3 and 4
Alnico 2 magnet : The Vintage Classic
The Alnico 2 is made of 10% Aluminum, 19% Nickel, 13% Cobalt and 3% Copper, the rest being iron. Pickups equipped with Alnico 2 magnets have moderate power with strong mids, receding highs and good sustain. It was very common on early humbucker pickups but was not used on Fender single coils, although today Strat or Telecaster pickups can be made with Alnico 2. Signature Slash pickups or PAF Antiquity for example, are equipped with this magnet. This is the most frequently used magnet, along with the Alnico 5, for humbucking pickups. A low definition combined with very present mids and a moderate output level make it a perfect choice for vintage blues / rock rhythms.
Alnico 3 : Jazz, blues, Archtop… and a lot more!
The Alnico 3 is set apart: it has no Cobalt in its composition. It is made up of 12% Aluminum, 25% Nickel and 3% Copper. He is the least powerful of all the ranks, but he overcomes this lack of power with a strong character. Pickups with this alloy are heavily loaded in the lower midrange which gives them that raspy sound so characteristic and hollowed out in the upper midrange. The bass is slightly behind but the sustain is excellent. When you send gain it grumbles seriously but if you lift your foot a little you can easily venture on Jazz, funk or reggae but with double coils. The Alnico 3 is used much less today by big brands. Gibson reserves it for example for the high-end models of its Custom Shop to equip its most faithful reproductions of Les Paul or ES-335 (Custombucker or MHS pickups). These famous Custombuckers Alnico III are not found in the trade and for good reason. The first Strat and Telecaster single coils of the 1950s had A3 magnets and then Alnico 5. Guitars equipped with Alnico 3 pickups are therefore quite versatile in the vintage register with a strong character!
The Alnico 4: Lord of Classic Rock
The Alnico 4 is almost a newcomer since it did not exist in the 70s although it carries with it the DNA of the classic rock and hard rock sound of this period. It is composed of 7% Aluminum, 14% Nickel, 24% Cobalt and 3% Copper. It has spread more recently and is used primarily for humbucker pickups. It provides a higher output level than the Alnico 2 as well as more brilliance and better definition. It is located halfway between Alnico 2 and Alnico 5. It is perfect for Classic Rock, Blues, Hard Rock or even metal. It very easily supports large distortions in a rather Old School register and becomes very bluesy as soon as the volume of the guitar is lowered.
And the winner is : Alnico 5
It is by far the most used magnet in the manufacture of electric guitar pickups. It has a substantial magnetic force, strong bass and treble, deep mids and very good definition. The sustain is slightly set back due to its strong magnetic force The Alnico 5 can be used with all sizes and types of copper wire, it supports over-winding without problem. Finally, it is equally at home in vintage and modern registers, everything will depend on the amp you plug it into. It is used in most modern or Hot Vintage humbuckers. Its versatility and widespread use, however, have a slight disadvantage: a certain lack of originality.
Does the size matter?
And yes, here size matters! We will make a first comparison between the magnet volume of a Stratocaster single coil with a Humbucker and a P90. The Strat pickup is made up of 6 cylindrical magnets of approximately 308 mm3 for a total of 1850mm3. The humbucker has a single parallelepiped magnet of 2500mm3. The P90 has two magnets identical to the humbucker, for a total magnet volume of approximately 5000mm3! The size of the magnet (s) directly influences the sonic character of the microphone and the output level. Now let’s take Seymour Duncan’s Invader: it is equipped with 3 magnets including an oversized one in the center (the usual place of the magnet in a Humbucker). The other two are on the sides, smaller in size, otherwise it won’t fit. It has a magnet volume of 7000mm3 and has the same winding as the famous JB of the same brand.
Modern alloys: Alnico 6, 8 and 9
Alnico 8: a supercharged Alnico 5
Among these 3 alloys, Alnico 8 is the best known even if its use remains anecdotal compared to Alnico 5. Its composition is as follows: 7% Aluminum, 15% Nickel, 35% Cobalt, 4% Copper and, this is new, 5% Titanium. It is used as an alternative to ceramic magnets (Ceramic 8 or C8) which it shares certain characteristics: very high output level, very high treble and excellent definition. My A8-equipped pickups are made to take heavy distortions while maintaining clarity and definition. The are clear are quite dry and tend to twist quickly depending on the attack of the pick. We reserve it for the bridge pickup although a paired set is quite possible.
Alnico 6: the outsider
The Alnico 6 is used even less often. Seymour Duncan integrated it into the Joe Bonamassa signature set to equip his 1958 flying V named “Amos”. It’s a magnet halfway between the 5 and the 8, from an output level point of view. It has very present bass and treble a little behind compared to the Alnico 5 while maintaining the hollow in the mids. Its tone darker than 5 and 8 while retaining a modern tone.
Alnico 9, a rare bird
It has a magnetic power equivalent to the Alnico 8 but with less treble and more medium. This small sound difference brings it closer to the more vintage Alnicos but with a very high output level. It has the same composition as the Alnico 8, the difference is in the manufacturing process. It would be a mix between the Alnico 8 and the Alnico 4 with which it goes perfectly in a microphone set.
Ceramic 8 magnets
We were talking about high output level with modern Alnico. The C8 delivers approximately double the more powerful Alnico 8. Suffice to say that we do not play in the same court! The ceramic magnet delivers very present bass, very deep mids and piercing, even aggressive highs. The clean sounds are freezing with this magnets, it is really made for the big distortion. It supports (even prefers) the overwinding which will remove the treble in favor of the mediums and thus rebalance the sound. You made extreme metal, take C8.
Find complete information about Alnico magnets on the page dedicated to them on Wikipedia.