Neo magnets and big distance from the strings: would I miss anything?

[David Schwab]

hello triad,
as far as I remember (can't find the book right now) erno swan ( hope this is the correct name) uses nothing but ferrite-magnets for the projects in his book. I don't think other magnets are discussed in animal magnetism. at the time the book was written it was really difficult to get alnico rods or neo-magnets.
chr.

I have that book. I don't remember him saying that. Alnico rods have been around for a long time. If you want to make a modern type of bass pickup, and you are using steel poles, ceramics make more sense than alnicos. Lots of bass pickups like Bartolini use ceramic magnets.

Obviously Zwaan shifted over to neo magnets for his Q-Tuners.

[David King]

I don't think of the Q-Tuners as being particularly bassy so whatever the neos are doing for him it isn't adding appreciably to the low end. I imagine that if the pole pieces were closer to the magnets and there wasn't such a gap all around the coils it might be a very different animal.

[David Schwab]

I don't think of the Q-Tuners as being particularly bassy so whatever the neos are doing for him it isn't adding appreciably to the low end. I imagine that if the pole pieces were closer to the magnets and there wasn't such a gap all around the coils it might be a very different animal.

Well it's also a sidewinder, and he's using very large magnets, so he needs the gap. On a humbucker the neos produce a lot of low end.

But I think his coil geometry and everything else was designed to get that tone he gets. My sidewinders don't sound like that, even if I use neo magnets.

[Mike Sulzer]

Magnets do not produce "low end"; they magnetize the string and contribute permeability for the inductance and the sensitivity of the coil and modify the circuit with eddy currents if they are conductive. Neos have permeability very close to free space and they are not very conductive. Think of them as not doing much of anything beyond providing the field to magnetize the strings.

Well it's also a sidewinder, and he's using very large magnets, so he needs the gap. On a humbucker the neos produce a lot of low end.

But I think his coil geometry and everything else was designed to get that tone he gets. My sidewinders don't sound like that, even if I use neo magnets.

[Peteus]

I guess i'm slightly high jacking this thread but, one of the guys recommended I could use a Neo on the end of each pole piece for a humbucker I'm building. For a guitar pickup what size of "small round" neo do people recommend so I don't get a massive string pull and made successful pickups with?

[Mark Hammer]

Is the Alnico-type/brightness relationship generalized to pickup form-factor (i.e., holds true across P90, PAF, SC, etc.), or true for SC w/polepieces only?

[Mike Sulzer]

I like little disks about the same diameter as the pole piece, between 1/16" to maybe 1/8" thick. You should try a range and see what you like. (This is for the end away from the string.) I once built a humbucker with 3/8" dia. 1/4" thick disks. It was really hard to assemble and totally destroyed the sound of the string. You might consider investing in a gauss meter some time. It is fun and useful to know what field you get at the string.

I guess i'm slightly high jacking this thread but, one of the guys recommended I could use a Neo on the end of each pole piece for a humbucker I'm building. For a guitar pickup what size of "small round" neo do people recommend so I don't get a massive string pull and made successful pickups with?

[David Schwab]

Magnets do not produce "low end"; they magnetize the string and contribute permeability for the inductance and the sensitivity of the coil and modify the circuit with eddy currents if they are conductive. Neos have permeability very close to free space and they are not very conductive. Think of them as not doing much of anything beyond providing the field to magnetize the strings.

OK, but as I said taking the same pickup, and swapping in different size neo magnets made a huge change in the tone, and not so much in outlet level. The large neo made the pickup very dark and bassy sounding. A smaller neo was bright sounding, as was a larger ceramic.

So something is going on beyond magnetizing the strings.

Let me see if I can find sound clips I recorded.

[edit]

OK. found them. Recorded in March 2010.

Here's the pickup mounted in the guitar.



It was recorded direct into a Roland VM-3100Pro digital mixer, and into TC Works Spark XL on my Mac via S/PDIF.

Unfortunately I had the levels a little too high and it's clipped. But you will still hear the difference. Nothing was changed between takes except swapping the magnet. Because I was able to pull the pickguard out from under the strings, I simply removed it from the guitar, swapped the magnet, and put it back.

Ceramic

Neo 1

Neo 2

So you can clearly hear that the magnet type and size changes the tone of the pickup.

This is the same affect I also noticed with bass pickup.

[Mike Sulzer]

So you can clearly hear that the magnet type and size changes the tone of the pickup.

The first clue that this test does not show what you think it does is that the level does not change much when you change the strength of the magnet. Theory, measurement, and listening all show that it does, unless something stops it from happening. The second clue is that you have a significant amount of non-linearity in all three cases, and that the non-linearity is significantly different in all three cases. One possibility is that the magnets cause different levels of output which cause different non-linear effects. Something in the processing could be equalizing the final levels, as well as adjusting the tone. I am just speculating, of course, but for sure this test does not show what you claim.

[David Schwab]

The first clue that this test does not show what you think it does is that the level does not change much when you change the strength of the magnet. Theory, measurement, and listening all show that it does, unless something stops it from happening. The second clue is that you have a significant amount of non-linearity in all three cases, and that the non-linearity is significantly different in all three cases. One possibility is that the magnets cause different levels of output which cause different non-linear effects. Something in the processing could be equalizing the final levels, as well as adjusting the tone. I am just speculating, of course, but for sure this test does not show what you claim.

What non-linearity are you speaking of? You are hearing digital distortion in the high end. The levels do indeed change. You can see this in the waveforms. However, because I was clipping the waveforms, they ran out of room, i.e., tops and bottoms flattened, on the two neo clips. And you can hear the difference in levels, but the difference wasn't that great. I said that in my post above:

swapping in different size neo magnets made a huge change in the tone, and not so much in outlet level.

The tonal differences were clearly evident when listening to the pickup. And you cannot deny that they sound different in the recordings. it was enough of a difference to make me put the small neo magnet in. I didn't like the way it sounded. I was looking for a brighter tone, and you can hear it's darker and has more mids.

There was no tone adjusting. As I said, the pickup is being run directly to the mixer, skipping any volume or tone controls. The pickup was connected directly to the output jack. I used a 15 foot Spectraflex cable into my Roland mixer's high Z input (1 megohm). The EQ section was defeated. I had the gain cranked to hear it well in my speakers (Monsoon flat planar + sub), and didn't realize I was clipping the input on the recorder (TC Works Spark XL). This was really setup as a listening test, and not so much for recording.

Rather than trying to find flaws in my method, why not say; "hmmmm that's interesting, I wonder why that might be?" That's how you do science Mike, not having your mind made up about something from the start. Then we might learn something new. This effect is repeatable, and I'd be happy to do it over with better recordings. I get the very same results with my bass pickups. And I use it to an advantage on some models. I changed nothing but magnet size, and I get a fatter tone.

This reminds me of when you didn't agree about the multi coil pickup not being muddy when wound hot, and then you did a test with low wind coils which missed the point entirely. You have to wind up past the point of diminishing returns. Any pickup wound to, what was it 4k?, is going to sound bright and clear. Wind a 10k coil and things are very different.

While we are on that subject, here's a 4 string single coil Jazz bass pickup wound to 8k.

This is just the bridge pickup.

https://soundcloud.com/davidravenmoo...idge-3-5-14-12

Now here's a 5 string multi coil Jazz bass pickup wound to about 9.6 k:
This starts out with the neck, and then both, and then the bridge. You can hear it's a lot brighter, and it was louder. If the single coil was wound that hot it would have sounded like mud. The two certainly sound different too. They both used the same wire and alnico 5 magnets.

https://soundcloud.com/davidravenmoo..._5-string-jazz

[Triad]

Thanx for taking the time to do this experiment, it's very interesting.

[Mike Sulzer]

What non-linearity are you speaking of? You are hearing digital distortion in the high end. The levels do indeed change. You can see this in the waveforms. However, because I was clipping the waveforms, they ran out of room, i.e., tops and bottoms flattened, on the two neo clips. And you can hear the difference in levels, but the difference wasn't that great.

You cannot hear the severe distortion on the ceramic as well? You cannot hear the additional distortion on the neos, clipping that limits the differences in levels? Then I am not sure there is much point in proceeding with this discussion, or any other, but I will give it a try nonetheless.

I am glad you acknowledge that there is significant difference in the levels. As I said, there is a big differene in the frequency responses, but the question is why? Could the stronger magnet move the magnetic state along the hysteresis curve of the steel in the blade, enough to alter the inductance a lot? I have always thought that is a very small effect, but who knows? You cannot just say "magnets sound different." So you see why I think there might be some problem with the processing.

As for science, one of the most important things is skepticism. This means that if you do a really bad experiment, and tell me you could do a better one, but say that I should believe the results of the bad one anyway, then I do not. It is that simple.

OK, let's review the other issue that you mention. I demonstrated a general theoretical result: winding one big coil or several smaller ones around the same cores should make little difference in the inductance, given the same total resistance, I believe. It was not necessary to state an exact number of turns to get this result. In particular, it has nothing to do with whether it is enough turns to sound muddy to you. I illustrated this with a specific case, both measurement and listening. The tests agreed with the theory. It was not your specific case (muddy) that I used; so what?

You say it does not hold when you use enough turns to make the pickup sound muddy. Why would that be true? I have theory, measurement, and listening agreeing. You have a listening test, but I cannot access those bass clips.

[Steve Conner]

As for science, one of the most important things is skepticism. This means that if you do a really bad experiment, and tell me you could do a better one, but say that I should believe the results of the bad one anyway, then I do not.

I'm sorry, but I have to side with Mike in this case.

[David Schwab]

You cannot hear the severe distortion on the ceramic as well? You cannot hear the additional distortion on the neos, clipping that limits the differences in levels? Then I am not sure there is much point in proceeding with this discussion, or any other, but I will give it a try nonetheless.

I am glad you acknowledge that there is significant difference in the levels. As I said, there is a big differene in the frequency responses, but the question is why? Could the stronger magnet move the magnetic state along the hysteresis curve of the steel in the blade, enough to alter the inductance a lot? I have always thought that is a very small effect, but who knows? You cannot just say "magnets sound different." So you see why I think there might be some problem with the processing.

As for science, one of the most important things is skepticism. This means that if you do a really bad experiment, and tell me you could do a better one, but say that I should believe the results of the bad one anyway, then I do not. It is that simple.

OK, let's review the other issue that you mention. I demonstrated a general theoretical result: winding one big coil or several smaller ones around the same cores should make little difference in the inductance, given the same total resistance, I believe. It was not necessary to state an exact number of turns to get this result. In particular, it has nothing to do with whether it is enough turns to sound muddy to you. I illustrated this with a specific case, both measurement and listening. The tests agreed with the theory. It was not your specific case (muddy) that I used; so what?

You say it does not hold when you use enough turns to make the pickup sound muddy. Why would that be true? I have theory, measurement, and listening agreeing. You have a listening test, but I cannot access those bass clips.

All three clips are clipped. The neos are actually clipped a little more.

Yeah Mike, clipping limits volume. Tube amps compress the signal because of soft clipping. If you want to try and match what I know about pro audio recording, please be my guest. Once you get past the available headroom, you don't get any louder, you get more distorted. In fact, fuzz pedals work the same way. How do you think you get the sustain from something like a Big Muff Pi? Lots of clipping.

There was not a large difference in levels. Since the ceramic is also clipped, and wasn't much quieter than the small neo, it was already just about out of headroom. The neos were a little louder, and the tops of the waveforms were flatter. If anything clipping adds high frequency harmonics, which actually made the darker sounding neo brighter. Thats how the aural exciter devices work.

Ceramic (some clipping on the peaks)


Small neo (lots of clipping)


Big neo (even more clipping)


You can clearly see that the two neo magnets made the pickup louder than the ceramic. You can also see that the two neo pickups are close in levels, but they don't sound the same. The smaller neo was not all that much stronger than the ceramic magnet. When I get a chance I'll take readings on them. I did this back in 2010. I didn't want to change the input levels, but if I had known the neos would clip so badly, I would have started lower. Since the recordings were not important, I didn't want to swap magnets again.

You are not being skeptical. You have a belief system in place. You believe that it has to match what you think you know as true. You said the magnet only magnetizes the strings and adds no low end. I hear more low end in those recordings, as well as in regular listening. Science learns new things all the time. Go back about 10 years and scientist said there is no way there was any water on the moon or Mars. And guess what? Lots of water. They even found water on Mercury. Discoveries are often made by chance, because we don't know everything. When science gets dogmatic, there is a problem. Skepticism works both ways. One must be skeptical of your findings as well, which is why I questioned why you wound the pickups so low, when the discussion was about over wound pickups. Overwound pickups are dark sounding. You under wound yours. Under wound pickups are brighter sounding. That limited the differences between the two sets, and still, your multi coil pickup was brighter. Just not as dramatically so as with over wound pickups.

What I wold like is you to think about the effect that's going on, not just dismissing it. If you want to repeat the experiment, exactly as I did, be my guest. But you can't change your experiment from mine and use it as proof of anything. Thats what you did with the multi coil pickups. it just proved that low wind pickups are brighter. that wasn't the test.

As far as my test, clipping aside, it was not an experiment. I was making reference recordings for myself. I do that with every new pickup design I try. That way I can come back after several more iterations and refresh my memory on where I was a few days ago. They ended up being bad reference recordings. So even if my recordings don't match what I was hearing, the effect is still there. All three sound different. I disliked the large neo and got a small one. The large one wound have been great for Jazz. And the pickup was only about 5.5k. In the end I didn't like the small one either and used the ceramic magnet.

The larger magnet works well enough that I used it to fatten up the bridge pickup on my Neo Jazzbucker set. I went with a larger magnet, and instantly had a warmer tone. While the recordings are not perfect, my test is valid because nothing was changed except the magnets. Same coils, same blades, same wiring, same recording setup. The whole thing was done is less than 30 minutes. The hight of the pickup did not change. I wasn't using the recordings to decide what version I liked, I was using my ears.

On to your multi coil test. You wound some very low output pickups. Anyone knows that the more wire you wind on the pickup, you get more lows and mids and less treble. But that's not going to happen on a 4k pickup. That wont even happen on an 8k pickup. But wind it up to 20K, like a Wal pickup and you will have mud. Like the old Guild humbuckers. They had almost no high end.

And even with a 9k Jazz bass pickup, it's not as bright as the 6K Jazz pickups. The first thing the guy who's bass the multi coil I made went into said was "wow, these are really bright sounding, way brighter than the old ones, and louder too." I used the same magnets and bobbins, I just cut them apart, and remagnetized two bobbins to be reversed. Unfortunately I did not record the pickups before I reworked them, but I had rewound them myself in the past. The bridge pickup was dead when he brought it to me.

As another example, this past week I made a dual Jazz humbucker bridge pickup for a customer's P bass. I made the pickup and wound it with 5,000 turns on each coil. It sounded very nice, very balanced sounding, but the 10k P bass pickup was louder and fuller sounding. He wanted a dark sounding pickup. So I rewound it with 8,000 turns on each coil. Now it as perfect. It has a lot less high end, and matches the P bass pickup very well. So more wire=less high end and more low end. If I had wound eight coils, it would have been as bright as the first pickup, and with having a slightly lower resonant peak, would have had more of a cutting tone, making it sound even brighter.

[Mike Sulzer]

"One must be skeptical of your findings as well, which is why I questioned why you wound the pickups so low, when the discussion was about over wound pickups. Overwound pickups are dark sounding."

The discussion was also about whether you can make a pickup brighter by replacing a single coil around a set of pole pieces with individual coils around each pole piece. I showed you that they sounded the same, with my number of turns. I also showed you why you would expect the inductance to be the same, in general. Why do yours sound different? Why do the single versus multi coil pickups sound different when there are lots of turns, but not when there are not so many? Changing the inductance affects the sound with brighter pickups as well as darker pickups, and since I showed that the inductance should not change, what is going on?