Neodymium-iron-boron polymer magnets

[Mike Sulzer]

I absolutely love that you don't think any of it useful. I'm not looking for a debate, just clarify for us you really believe so long as gauss strength is set proper around the string, the return path and gauss strength at other locations within the coil are of no value? The only place of value is where the string is?

Yes, of course, that is true for the permanent field.* Its only purpose is to magnetize the string. On the other hand, the flux path of the field from the vibrating magnetized string does matter. It is the flux from the vibrating string passing through the coil, than induces the voltage in the coil.

An example of this is the Lace pickups that David King mentioned. Assuming that the Wiki article is correct, these pickups intend to magnetize the string with a lower than normal field strength to avoid string pull, but still get a high output. So you use weak magnets and a core structure that results in this lower field level at the string. In order to make up for this lower than typical string magnetization, you attempt to capture more of the flux from the vibrating string and get it to pass through the coil. In order to do this, you might use some steel (high permeability), or possibility other material such as ceramic, to guide the flux from the bottom of the coil back up towards the string in order to shorten the path through air. This steel would also tend to increase the permanent field strength at the string, so you have to be sure to use weak enough magnets.

*And despite your sarcasm, it has nothing to do with my beliefs. It is how the physics works. I suggest again looking at the solution referred to in the "Light reading" discussion. You do not have to understand the math to follow the basic steps.

[MrCandy]

Thank you gentlemen for your interest in such an interesting and promising topic, we appreciate it.

I've even dreamed of a type of "magnetic paint" that would be aligned by a magnet within proximity while the "paint" was curing. Not like ferrofluids, which don't retain magnetism, but more like what Mr. Candy is referring to but with highly customized polar patterns, built in focusing and defraction, etc. If Mr Candy can make truly custom pieces, that could be motivating for someone like us, but doesn't assist in a group buy due to the specialized nature of the part, and any company our size or a guitar company would request the exclusive on the part as well.

Yes Frank,the Subject is very promising and flight of scientific thought can be unlimited.
We have already own a lot of ideas how to use these products and I think you have them too.
Next week we will have a number of sound and measurement tests for these magnets that we will share here.
Also if you are interested we can cooperate with your great company, the more so you must have secrecy of the negotiations
document in the archive signed by Andrey Rybakov.

Transfer hi to Evan Skopp if nearby.
Andrey Rybakov.

[David King]

So we'll be able to 3-D print our own proprietary neo magnets if we can just buy the right ink cartridge?

[frankfalbo]

Mike thanks for the clarification of your position, its less different from mine than your first post suggested. I had already read the light reading thread and could engage on some of the conclusions drawn there. But as I suggested, I can't really debate more, in no small part out of respect for my company and confidential R&D projects or discoveries. I still contend that controlling the flux path in and around the coil geometry by means other than steel appendiges, including exploring customized gauss patterns contained within the finished magnet dimension itself has value. We can leave it at that.

[David Schwab]

There are ceramic rods; I have used them in various pickups, including those with six coils.

Didn't you use ferrite cores with neos on them? They aren't permanent magnets, right? I think he was referring to ceramic rod magnets.

[David Schwab]

The LAce Sensor pickups use(d) flexible ferrite magnetic sheet material and they sound nothing like ceramic pickups so I'd be of the opinion that a soft elastomer matrix around a hard magnetic material (high coercivity) will give very different results from it's sintered or molten-cast cousins.

Don't forget Rickenbacker pickups, some of which use rubber magnets.

[David Schwab]

I still contend that controlling the flux path in and around the coil geometry by means other than steel appendiges, including exploring customized gauss patterns contained within the finished magnet dimension itself has value.

Reminds me of the Attila Zoller pickup, patent #3588311. It was a very well regarded jazz pickup.

[Sweetfinger]

So we'll be able to 3-D print our own proprietary neo magnets if we can just buy the right ink cartridge?

Don't see why not!
I can envision a couple places where this might work nicely, like the magnet for a Dearmond "Hershey bar" style pickup or having the molded plastic bobbin for a Dynasonic BE the magnet. Perhaps a new take on the ol' "Eye Beam". What does the actual surface of the plastic look like? if it can be polished, or comes in colors and looks pretty groovy by itself I could see a real sexy molded string through design for a lap steel.

[FunkyKikuchiyo]

Didn't you use ferrite cores with neos on them? They aren't permanent magnets, right? I think he was referring to ceramic rod magnets.

Yeah, that is what I meant. Basically I'm thinking of a pickup wherein no part (except the coil) is conductive enough to put a meter across it and read open. A ceramic rod would do that, and I don't think I've ever seen such a thing.... probably would be too strong, which is why I never gave it much thought until recently. I wouldn't expect it to sound amazing, but it would make for an interesting experiment, I think.

[Mike Sulzer]

Yeah, that is what I meant. Basically I'm thinking of a pickup wherein no part (except the coil) is conductive enough to put a meter across it and read open. A ceramic rod would do that, and I don't think I've ever seen such a thing.... probably would be too strong, which is why I never gave it much thought until recently. I wouldn't expect it to sound amazing, but it would make for an interesting experiment, I think.

If you goal is to have no significant losses in the pickup except in the wire resistance, the rods that I have used that are permeable but are not permanent magnets will do that just fine (although they are slightly conductive). The small neos that you need to put on do not have much loss.

[Mike Sulzer]

Reminds me of the Attila Zoller pickup, patent #3588311. It was a very well regarded jazz pickup.

Well, that is an odd pickup with one outer magnet with N/S up and the other across. Is the central piece that the screws go into just steel or is it also a magnet? The major effect on the string magnetization would seem to be to spread it out along the string, but by different amounts in the two directions, but also make it more horizontal. But there would be little useful effect since the horizontal component of the magnetization contributes little to the flux pointing through the coil.

[David Schwab]

But there would be little useful effect since the horizontal component of the magnetization contributes little to the flux pointing through the coil.

Except it does have an affect. He wanted a wide field to get a certain tone, and he got it.

SH AZ 48 Attila Zoller floating jazz guitar humbucker

It's been considered the best jazz guitar pickup for quite a while. Zoller developed it by trail and error, so he he was using his ears and not thinking about what would or wouldn't work.

[frankfalbo]

Sounds pretty good to me. Too bad he didn't have today's technology and software, he would have realized how silly his design was.

[David Schwab]

Sounds pretty good to me. Too bad he didn't have today's technology and software, he would have realized how silly his design was.

There's a nice modern recorded sound clip at the Shadow website:

playaudio

[Mike Sulzer]

Except it does have an affect. He wanted a wide field to get a certain tone, and he got it.

The pickup in the patent does not appear to be a humbucker; I think the one in the sound clip is. Am I missing something?


"Except it does have an affect": I really do not think it can. You do not know that the sound and the claimed reason for the sound have any relationship, and they appear not to in this case. That pickup is like any other in that regard: The sampling area is given by where the string is magnetized most strongly with a direction through the coil. That is located near the screws.

The pickup apparently has a lot of metal, a lot of eddy currents, and so a very low Q and a flat response over the somewhat limited frequency range where jazz is best played.. When dealing with audio, the first thing you look for is frequency response. That explains most things. (In an active system you also look for overloading, of course.)

In a pickup you also have a non-linear response that can be somewhat a function of pole piece geometry, etc. But no, there is no wide sampling area from magnetizing the string over a wide area along the string rather than perpendicular to it.