AlNiCo types vs. Ceramic and other tales.

[sydsbluesky]

Off on a tangent...

A year or so ago I discovered that different pickups have different magnets... well, not to say discovered, but became aware of to an almost painful extent, having never seemed to take notice of such a thing before.

I was researching my first set of actives at the time, and noticed on the EMG site all the models came in Ceramic, and then some had an "A" after them. P-60A(mini hums,) SA(singles,) 60A (humbies) and even PA (base pups.)

My mind having been opened to this new technical playground, I read everything I could find on the p0rn machine about magnets (see? they -can- be used for other things!) in pickups... materials, shapes, sizes, strengths... well, here's my tangent on my findings for make benifit glorious nation of GuitarNutz2.

Can google up more info on the AlNiCo magnet grades and the engineering aspects of the magnetic fields and all that dog pile someplace, but here's the quick and to the pointless of it.

ALNiCo= alloy of Aluminum Nickle and Cobalt.

Nickle and Cobalt are both magnetic in nature, while Aluminum is not, so by switching up the amounts in the mix, you get AlNiCo numbers. II, V and VII are the most common, but Duncan makes a VIII and even maybe a IV... Dunno off the top of my head.

The higher the number is, the stronger the magnet is... stronger magnet means more output.

Lower ones tend to have mellower, warmer tones, while the stronger ones tend to have crisper highs and punchier lows.

The 57's mellow, warm tone is from the AlNiCo II working in concert with the vintage pickup cover - try pulling it off for a little different sound - the wiring and the even bobbin winding... there are a TON of things at work in each and every example.

Ceramic...

Ceramic has a different magnetic field compared to AlNiCo. AlNiCo actually dampens the string vibrations, creating what I feel is a little more expressiveness. Ceramic generates the flatter sound with a little less expressive possibility... Obviosuly not all expressive Pups are AlNiCo, and not all flat ones are ceramic, but the flatter ones tend to be ceramic. (EMG 81, anyone?)

Dave Gilmour played EMG SAs in the red strat. EMGs S pup, but with AlNiCo bar instead of ceramic.

Trend that you tend to see across the board is AlNiCo in neck and Ceramic in bridge, when the two are mixed on the same guitar. This includes the dreaded 81/85 set. *cringes*

You'd have to look elswhere for more comprehensive comparing/contrasting.. Maybe tonight I'll internet it up a little and find more info for this.... I personally find it fascinating... What? don't you? *clears throat and moves on*

Other things to consider is rail magnets vs pole magnets. Rails have a steady volume with bent strings, where as pole pieces can loose some of their pull as a string moves away from the pole.

Active pups in the briefness...

Actives...use much smaller magnets (hencs the placement closer to the string and the lower resistasnce on the pots) and THUS, the magnets will tug on the string less.

In which case, the AlNiCo actives act more - in at least this one way - like ceramic.

.... also less magnetic tug means more sustain.


But theory is one thing and practice is another.

When I go shopping I tend to ignore the theory, but it's always there for food for thought.

There you go. The quick and to the pointless of pickup magnets.

[ChrisK]

Actives...use much smaller magnets (hence the placement closer to the string and the lower resistance on the pots) and THUS, the magnets will tug on the string less.

While the smaller magnets do allow one to adjust the pickups closer to the strings, the smaller magnets also force one to adjust the pickups closer to the strings.

The value of the pots is unrelated to the size of the magnets and relates only to the desired output impedance of the active amplifier stages.


So you want to investigate magnets.......


www.rare-earth-magnets.com/?gclid=CJyb6sP56I0CFQNYYQod2hPtEA

www.rare-earth-magnets.com/magnet_university/types_of_magnets.htm

www.magtech.com.hk/index_product.htm

www.aqdi.com/cgi-bin/database.cgi

The start and end point for the formal study of electromagnetic theory is QED

[sydsbluesky]

I never said one caused the other... just that the pot values indicate the relative strength of the magnets if nothing else is in the way.

I mentioned soem of the EMG gadgits that can be added in to change impedance. The lower impedance is encessary because the output of the actives is very LOW from the magnet and BOOSTED by the active preamp (powered by the 9 volt.)

Which is why with an EMG PA2, for instance, you can put it in after your signal passes your pots and get low impedance without havign to change the pots... it'll cut it down to 2K, then boost it with the preamp before sending it off at low impedance... or at least that's how it was explained to me.

I'm a bio major... engineering isn't my department, so I'm just repeating what I've been told by various sources.

[ChrisK]

I was just commenting that the pot values indicate the relative activity of the electronics output rather than the passive coil's input impedance.

[sydsbluesky]

We need a physicist to translate QED into tone lol

Okay... now I'm home from work and have a moment.

I had a forum bookmarked someplace with exactly that... an electrical engineer that consulted for a pup... designer, or something. I wish I could find it again.

I'm going to dig and see what I can unearth on the subject of translation into layman's terms.

[sumgai]

Uhh, syd?

We're not all exactly what you'd call "laymen" here. Several of us here are indeed engineers, at least three that I know of.

If you want/need to get the actual physics of how a pickup works, we've discussed this before. Use the Search option in the menu just below our site's logo, and be sure to go back at least 600 or 700 days (it has been awhile).

One of the better off-forum sites that deals with how a pickup works, and particularly the effects of various magnet materials, can be found here. (This site is full of self-serving marketing speak, but what he says about the underlying workings of a pup is nonetheless true.)

HTH



sumgai

[sydsbluesky]

that layman I was talkin about is me.

I tried searching the site with the day count at 999, but I didn't get anything.

I dug through the forum a bit and found some links posted by chrisK that were helpful. I sent him a message letting him know that I found them interesting, but I wasn't able to really find anything on the forum itself linking the physics to the tone... I guess I'll look a bit harder.

I was hoping for a bit more of the personal experience/preference/findings in this related to the ear instead of bouncing off into the engineering department with this thread, andgetting a link to the wiki on quantum electrodynamics and commercial magnets.

But yeah... I'll go down to the physics department and see if my buddy can help me get a better understanding, since all these links seems to be above my head.

...maybe something in layman's terms.

[ChrisK]

This is a process called calibration. We're getting calibrated with each other.

While there are engineers a'board, we look to learn from your discoveries as well. I can say a bit about magnets, but not necessarily about how they sound specifically. There are many variables.

A good place to look at is Duncan's three CD set of tone clips for their pickups. These were recorded in reference platforms (same guitar/amp/settings/riff/player) where one can discern the actual differences. Now of course, these are for their different pickups and not their same pickups with different magnets, except for a couple of examples. One is the SH-5 and SH11 as one is alnico5 and one is alnico2 with the same coils. There are also the 2-5 pickups that use different magnet material for the low and high strings. These may be permutations of other pickups as well.


While I cannot speak to the veracity of this link, it purports to offer controllable variation based on guitar type.

www.aqdi.com/cgi-bin/database.cgi


This is a good patent on pickup technology as it is recent and cites a number of relevant pickup patents over the years. Enter the patent numbers into google patents and you're on your way.

www.google.com/patents/about?id=oymAAAAAEBAJ&dq=7,227,076

Note that the inventor (Willi Stich) is also known as (the) Bill Lawrence and these pickups are the Fender SCN series. (Based on past verbal (and nounal) conversation with him, I can assure you that he's aware of QED.)

[sumgai]

syd,

OK, fair dinkum. The school of thought that you're really asking about is not physics, but psychoacoustics. That's pretty hard to quantify, but nonetheless, we (some of us innerweb denizens) have made a start at it.

Try this link to see harmonic relationships. You won't hear anything, but you will see, graphically, why certain factors are big influences on what we do hear, and how we can make those factors work for us (instead of just wishing and hoping that they come together in a way we might like).

My final thought for you is, always keep in mind that one man's "open airiness" is another man's "ice-pick shrill". IOW, tone is in the ear of the beholder, and what suits me make make you cringe. Take all marketing hype with a large glass of stout or pale ale. Take all reviewers' opinions with a dime baggie. ;D Mortgage the house, buy a set of every type of pup you wanna try, and sell the leftovers on eBay or craigslist. (Then pay back the mortgage! )

HTH



sumgai

[sydsbluesky]

This is more like it!

Tonight I'll have the time to scour all of these links after work.

And yeah, sumgai... I'm on a Quest, no, an odyssey, to run every pickup I can think of through my Dr. Jessinstine's ESP MH monster.


ESP MH-200:
Body wood - best guess Agathis? That's what the model uses now...
Neck - maple with a rosewood digitboard. Medium wire.
Floyd lic. bridge, replaced with guitar fetish version. (currently set to the body with a piece of oak hardwood flooring behing the block... did that the same time I installed the current pup, the SH-1, so...)
Fully rewired and chromed out.
Elixer 10s nanoweb strings.


So far I've done stock (CRRAAAPPPPYYY duncan designed pups made by ESP to the schematics loosely scrawled on what I'm sure was second hand cardboard using a pen perilously low on ink,) Seymour duncan SH1(current,) Duncan SH2, Gibber '57 for neck, and I've done stock and the JB in the bridge... I never use the bridge, so I couldn't care less. And I'm putting a set of Duncan Livewires in within the next week.

Wanted to try the actives.

Played them all for a while through the same amp, speaker, cable and OD pedal. (Marshall 100AVT, big butt 320 watt crate cab loaded with celestian custom 80 watters, and boss blues driver, connected with two of the cheap monster cables.)

So... I'll get there yet!

But.. SO FAR results are...

AlNiCo II = good cleans in what I would call a "bright" body, but being obsessed with neck pups, it doesn't have the leads I like to hear. This is the case with both the 57 and the SH-2. I actually prefered the Duncan, but could be the wood behind the block.

The SH-1 is similar to the SH-2, but with a Nicko V. Very good, well rounded pup. Deserving of it's excellent reputation.

The SH-1 vs. SH-2 shows all the classically listed differences between V and II.

I play all of my pickups with open coils except the 57... and the livewires, which are gonna be plastic covered.

The H is my jamming and gigging main, mind you, so I don't get to fiddle with it as much as I would like.

And I shall pour myself into those links like Robert Plant into 10% spandex 90% denim jeans once I get home. I'm sure I'll have some questions after I do.

Always glad to be lent an ear by those in the technical know.