Aperture question

[bfhoo]

SRV also tuned down a step, so he might as well had 9's on the guitar. It all equals out in the end.

A lot of players use 9's and get a good tone without a lot of effects. Take Brain May for example, he uses 9's. That's also a 24" scale guitar! He never sounds plinky.

SRV used 10's or 11's, not 14's as legend tells.
On the other hand, Hendrix used 08's, talking about plinky...

[Possum]

....

SRV used 12's then went to 11's. Hendrix used 9's. There is no comparison between an 11 gauge high E string and a 9 gauge high E. The 11 has more mass, is louder, less tinny because of the mass. If Stevie could have got that tone out of 9's I'm sure he would have used them. 9's sound like crap on a big archtop. Its all a matter of taste, I don't like the wimpy tone 9's get, I don't like effects or master volume amps so no 9's for me. Shit, when I was a kid all you could buy were Black Diamond 12 gauge strings, those things were a bitch to play but man they roared....

[David Schwab]

On the other hand, Hendrix used 08's, talking about plinky...

That's not what Jeff Beck says:

Jimi Hendrix became a friend and confidant of Beck's during the Jeff Beck Group period (1968). Hendrix gave Beck several pieces of guitaristic advice. "On my early stuff, I was playing the thinnest strings you could get," says Beck, ".008s. And then the Jimi man came along and told me, 'You can't play with those rubber bands. Get those off there.' So my string gauges have been creeping up ever since. Now I've got .011, .013, .017, .028, .038, and .049. I'm trying to get heavier on the top end." It was also Hendrix who rekindled Beck's interest in the Strat.

And:

The Gear of Jimi Hendrix

The String Thing

Hendrix’s strings of choice were light-gauge Fender Rock ’N’ Roll sets (gauged .010, .013, .015, .026, .032, .038). However, guitarist/producer Bob Kulick—an acquaintance of Hendrix’s during the Greenwich Village days—remembers him breaking a string in a dressing room, and saying, “Uh oh, I don’t have any extras.” Kulick asked him what he needed, and Hendrix said he used an E string for a B. “That was the first time I’d ever heard of anyone moving their string gauges over like that,” Kulick says.

But, then again, Band of Gypsies drummer Buddy Miles insisted that Hendrix used a very heavy E string, a medium gauge on his A and D, a Hawaiian G string, a light B, and a super-light E. This was supposedly not just for experimentation, but something Hendrix did because he thought the mixed gauges would keep the guitar in tune better. (Michael Bloomfield apparently tried some of the Hendrix Strats that Miles owned, and he was also a proponent of the mixed gauge theory.)

For picks, Hendrix chose whatever medium gauge his hand came up with when he stuck it into the drawer at Manny’s. Barrett simply reports that the Experience carried thousands of picks, as well as hundreds of guitar straps—all selected to match Hendrix’s shirts.

So, Hendrix used 10's, not 8's.

[David Schwab]

SRV used 12's then went to 11's. Hendrix used 9's. There is no comparison between an 11 gauge high E string and a 9 gauge high E. The 11 has more mass, is louder, less tinny because of the mass. If Stevie could have got that tone out of 9's I'm sure he would have used them.

I don't like the way an 11 E string sounds... not snappy enough unless you tune down a little. 10's are good. Don't forget that SRV tuned down. 9's a step lower would be very floppy. 8's are awful. I used to use 8's on my Vox 12-string though. That was the only way to get that thing playable.

I think there is an optimum tension for a given scale length and pitch. Heavy gauge strings sound weird to me. On an electric anyway. Same thing for me on bass. I like .045 sets. .050 is too heavy and .040 G strings sound thin. But like you said, it's all personal preference. I like guitars to be bright and snappy.

9's sound like crap on a big archtop.

They don't have enough mass to drive the top.

Shit, when I was a kid all you could buy were Black Diamond 12 gauge strings, those things were a bitch to play but man they roared....

I used to use those too. Man they were awful strings! My fingers heart thinking about them! I was happy when I found EB Slinky's.

[bfhoo]

I think heavy strings are adored more because of their feel than their sound. At least I like thin neck with big strings. On the other hand, I have noticed when you play with heavy gauge, you learn to use "too much force". I break strings more often with 11's than 09's...

[salvarsan]

This question is a bit complicated, and it needs a careful description of how a pickup works. Let's start by determining this: what does "aperture" mean to you?

Response Effects of Guitar Pickup Position and Width



1 of 3 articles on pickup aperture, et.al.


-drh

[Mike Sulzer]

Response Effects of Guitar Pickup Position and Width



1 of 3 articles on pickup aperture, et.al.


-drh

From the link you gave:

"Pickups do not sense the string at a single point source, but rather over an area due to the width of the magnetic field. This sensing area is called the "aperture" of the pickup and is about an inch wide on a thin single coil pickup and about 2.5 inches wide on a wider pickup such as the Gibson humbucker."

Tillman says that these are approximations, but I do not think he realizes how bad they are. The aperture function can be thought of as the product of two functions, one due to the distance over which the string is magnetized, and the second due to the sensitivity of the coil to the changing magnetic flux from the string.

1. String magnetization: This is determined by the cores (or magnets, if used as cores). It has nothing to due with the width of the coil itself. It falls off very quickly with distance along the string because the field from the core or magnet falls of quickly. The function is not much wider than the core width. For a humbucker, it is even more extreme. It is the vertical pointing field that counts for the most part, and this is extremely small between the two coils of a humbucker because the fields point in the opposite directions and tend to cancel in between the coils.

2. Coil sensitivity: This divides into two parts:
a. The coil alone
b. The effects of the cores

a. The coil alone: A wire loop is sensitive to flux that passes through it. Thus a winding on the outside has a wide sensitivity, while one wound around close to the core has a narrow sensitivity. Add up the sensitivities of all the windings and you get a triangle shaped function with a flattened top. (Remember that this function would multiply into the one for the magnetization; so this tends to narrow the total function further.)

b. The effects of the cores: If the cores have high permeability, such as the steel cores of humbuckers, the flux pattern from the string is modified. The flux from the part of the string just above gets drawn through the core, effectively amplified. The flux further away does not get affected so much. This tends to narrow the aperture even more.

[defaced]

On the other hand, I have noticed when you play with heavy gauge, you learn to use "too much force".

This has significantly impacted my playing style and has really impeded my ability to learn to play "light and fast". Over the past several years I've been weening myself off of heavy string in favor of lighter string to re-teach myself how to play. Not a fun endeavor. But I agree with Possum completely, heavy string sound are where it's at.

[ShannonH]

soo lemme get this straight...

2. Coil sensitivity: This divides into two parts:
a. The coil alone
b. The effects of the cores

a. The coil alone: A wire loop is sensitive to flux that passes through it. Thus a winding on the outside has a wide sensitivity, while one wound around close to the core has a narrow sensitivity. Add up the sensitivities of all the windings and you get a triangle shaped function with a flattened top. (Remember that this function would multiply into the one for the magnetization; so this tends to narrow the total function further.)

b. The effects of the cores: If the cores have high permeability, such as the steel cores of humbuckers, the flux pattern from the string is modified. The flux from the part of the string just above gets drawn through the core, effectively amplified. The flux further away does not get affected so much. This tends to narrow the aperture even more.

So the best way to get a wider aperture is to
1. Use a wider overall coil
2. Use a large magnet vs. a steel core of some sort

Did I understand that correctly?

[salvarsan]

The aperture function can be thought of as the product of two functions, one due to the distance over which the string is magnetized, and the second due to the sensitivity of the coil to the changing magnetic flux from the string.

We know.
We did the finite element magnetic models a few years before you showed up.



-drh

[Mike Sulzer]

So the best way to get a wider aperture is to
1. Use a wider overall coil
2. Use a large magnet vs. a steel core of some sort

Did I understand that correctly?

It is primarily determined by the magnetic core, whether it be a permanent magnet or steel pole pieces; it does not matter which. The coil can make the aperture somewhat narrower, but not too much; so I would not worry about making the coil too wide.

[Mike Sulzer]

We know.
We did the finite element magnetic models a few years before you showed up.



-drh

That is interesting. Who is we? Are the results available somewhere?

[Possum]

...

Hendrix's favorite guitar, a black strat, is in the posession of some lady who's name I've forgotten, someone measured the strings on that one and they were 9's FWIW. Jimmy Page sure knew with to do with 8's. Billy Gibbons uses 8's even now from what I've heard. I like 11's but am probably moving more back to 10's lately, I like to do big string bends now and then and don't need to be hurting my joints, which can take a long time to heal. I think there may be some confusion about early string gauges, from what I remember Super Slinkys when I was a kid were 8 gauge, now they are 9 gauge but the same name. The same thing may be happening when referring to Hendrix's strings. Anyway, he obviously didn't use heavy strings.

[salvarsan]

That is interesting. Who is we? Are the results available somewhere?

Andy of Wizard Pickups, Possum, Me ... Steve Kersting of SK Guitars is the only one who left the results up. *You are quite free to research the Ampage archive for more names.


Magnetic fields in pickups


While the field plots were initially interesting, they remain unusable in the absence of useful magnet material tests. *Remember that the Extech LCR meter is a major expense for a lot of pickup builders, so purchasing or building a device to generate BH curves and minor hysteresis loops is a complete non-starter here.
On the modeling side, the FEMM software group not only refused to help with design of more sophisticated pickup models but ruined their credibility by not correcting their Alnico data sets. *Alnico 8 has a permeability of 6.6?



In short, magnet modeling was briefly diverting but not especially germane to pickup building. *People got pretty pictures and a slightly better understanding of magnetic circuits, but nothing that improved their pickup-building craft.
-drh

[Joe Gwinn]

On the modeling side, the FEMM software group not only refused to help with design of more sophisticated pickup models but ruined their credibility by not correcting their Alnico data sets. *Alnico 8 has a permeability of 6.6?

If I recall, FEMM allows one to define one's own magnetic materials.

The biggest problem with FEMM is that it's 2D, but even so it can do a pretty good job on the center of a blade pickup.