The "MRI" magnetic Assembly

Rick Aiello · Post by **Rick Aiello** » 20 Dec 2004 5:06 pm

Here's the prototype of the most powerful magnetic assembly to date ...

A gnarwlin' 850 gauss (midgap) monster ... and I was HOLDIN' back ... that will fit in any standard horseshoe magnet bay ...

This particular version was built to house Jason Lollar's "Pole Piece-less" bobbin ...

I have another that will hold a standard "Pole Piece" bobbin ...

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Aiello's House of Gauss


My wife and I don't think alike. She donates money to the homeless and I donate money to the topless! ... R. Dangerfield
[This message was edited by Rick Aiello on 14 January 2005 at 01:07 PM.]

Dan Sawyer · Post by **Dan Sawyer** » 20 Dec 2004 5:45 pm

Very cool, Rick! Are you planning to install this in any refrigerators… oops, i mean guitars?

Peter Jacobs · Post by **Peter Jacobs** » 20 Dec 2004 6:18 pm

And I was just thinking, "What can I use to attach this guitar to that aircraft carrier..."

Yikes! The iron in my blood is being polarized as we speak!
[This message was edited by Peter Jacobs on 20 December 2004 at 06:19 PM.]

Gerald Ross · Post by **Gerald Ross** » 20 Dec 2004 6:21 pm

The strings fit through that narrow slot without buzzing?

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Gerald Ross
'Northwest Ann Arbor, Michigan's King Of The Hawaiian Steel Guitar'

Gerald's Fingerstyle Guitar Website

Rick Aiello · Post by **Rick Aiello** » 20 Dec 2004 7:49 pm

Yep ... plenty of clearance

Very cool ... Jason out-did himself on these

[This message was edited by Rick Aiello on 14 January 2005 at 12:57 PM.]

Travis Bernhardt · Post by **Travis Bernhardt** » 20 Dec 2004 9:02 pm

I was wondering why every time I put my keys down they rotated towards Berryville.

-Travis

Mike D · Post by **Mike D** » 21 Dec 2004 7:20 am

Will a warning to people with pacemakers be included with the P/U Rick?

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Half-assed bottleneck and lap slide player. Full-assed Builder of resonator instruments.

Rick Aiello · Post by **Rick Aiello** » 21 Dec 2004 8:00 am

Yep ... and for folks with steel implants too

Seriously, unlike its cousins ... I found a way to "direct" the bulk of the flux to the interior ... basically less "leakage" ...

A paper clip is only lightly drawn to the outer shell of this rascal ... where it would "launch" off my desk before.

I really needed that kinda "juice" for Jason's "Pole Piece-less" bobbin ... cause there are no pole pieces to concentrate the flux density under the strings.

So to get roughly the "equivalent" response as in my H-Shoe ... I had to bring the flux density to at least 800 gauss in the interior.

I made one thats 1250 gauss too ...

I'll have to back way off for a pole piece bobbin ... but thats no biggie.

[This message was edited by Rick Aiello on 14 January 2005 at 12:58 PM.]

Ray Minich · Post by **Ray Minich** » 21 Dec 2004 11:24 am

That thing would probably bend a beam of light

Mike Neer · Post by **Mike Neer** » 21 Dec 2004 12:52 pm

Whoa! That thing will take an MRI of your strings, for sure.[This message was edited by Mike Neer on 21 December 2004 at 12:52 PM.]

Dwayne Martineau · Post by **Dwayne Martineau** » 21 Dec 2004 1:38 pm

a gnarwlin' 850 gauss

What's the range for a regular lap steel pickup, say a Supro or old National...?

Rick Aiello · Post by **Rick Aiello** » 21 Dec 2004 2:41 pm

Basically it depends where you put your probe (watch it Howard) ...

I measure horseshoe type magnets flux density "smack dab" in the middle / mouth of the magnet ... I call it "mid gap".

A Rickenbacker ... about 200-225 gauss.

Fender Trapazoids ... about 150 gauss ... mid-way between the upper and lower steel "yolks" ...

Supro type string-thru (2 magnets) ... about 85 gauss ... mid-way between the upper and lower steel "yolks" ...

For a conventional pickup comparison ... my Stringmaster reads about 400 gauss at the height of the string ...

Rick Aiello · Post by **Rick Aiello** » 21 Dec 2004 3:21 pm

The "Star" of the show ...

[This message was edited by Rick Aiello on 21 December 2004 at 03:29 PM.]

Denny Turner · Post by **Denny Turner** » 24 Dec 2004 7:05 pm

Rick,

Just curious: What contributions and effect does such high gauss have on string drag? Are the magnets focused to a +/- gauss plane for the strings so there isn't so much of one polarity of that large a gauss pulling the strings? Is there also a similar latteral consideration to the outside strings vs inside strings exposure to the closed loop magnets' latteral ends?

I'm glad you clarified the external field strength; I was beginning to visualize colored sparkles of a worm-hole dancing in that coil's string tunnel ...and beginning to think a Picker might need an eyeball x-ray clearance to play that monster!

Another curiosity just occured to me: How much g-force does it take to erase the ROM in an electronic watch?

Wishing all the Happiest of Holiday Seasons.

Thank You,
Aloha,
DT~
[This message was edited by Denny Turner on 24 December 2004 at 07:25 PM.]

Paul Arntson · Post by **Paul Arntson** » 25 Dec 2004 3:34 am

Merry Christmas to All!
Denny - I think it depends on how fast your watch is moving when it gets in the field.

Rick -
That pickup is awesome. Is that an 8 string model? I've got to go back and review my copy of The Philadelphia Experiment before I order one...

Rick Aiello · Post by **Rick Aiello** » 25 Dec 2004 7:01 am

Denny ...

To give you a different perspective and to show that the field is not as strong as it "sounds" ...

In a standard Ricky horseshoe pickup (fully charged 1.5") ... say 210 gauss (mid-gap) ... once the bobbin is in place ... things really change.

The effect of the pole pieces is 2-fold ...

1) The ferrous slugs "concentrate" the lines of force (they like steel alot more than air) ...

2) The "Air-Gap" (space between pole tops and magnet) is greatly reduced ...

This results in a flux density of around 1000-1200 gauss ... affecting the strings ...

As with the MRI assembly, "H-Shoes" and standard horseshoe magnets ... there are equal yet opposite force vectors acting on the strings ... basically cancelling each other out ...

So unlike conventional pickups ... the "string drag" isn't really a factor ... as long as your strings are properly positioned.

These MRI's were developed to generate a field in the same "strength range" as a horseshoe pickup ... in a "Pole Piece-less" bobbin ...

As far as you watch ... just don't lay it inside the "MRI" and you are good to go ... ha, ha

Back to the Christmas un-wrapping ... just needed a break

Merry Christmas y'all ...

[This message was edited by Rick Aiello on 14 January 2005 at 01:00 PM.]

Rick Aiello · Post by **Rick Aiello** » 25 Dec 2004 8:54 am

Back for another "break in the un-wrappin' action" ...

Is there also a similar latteral consideration to the outside strings vs inside strings exposure to the closed loop magnets' latteral ends?

Because of the unique Orientation of the field within' the central cavity ... there is complete uniformity in field intensity ... each string "sees" the exact same thing ...

This orientation is "impossible" to achieve with a standard horseshoe magnet configuration.

Paul, one of the great things about Jason's "Pole Piece-less " coil ... any number of strings can be used ... restricted only by the distance spanned by the outermost strings.

This particular one has a 3" orifice ... it'll accomodate all my 8 string guitars ... except my Sierra.

Back to the presents ...

Loni Specter · Post by **Loni Specter** » 25 Dec 2004 4:44 pm

Rick,
You must be a Democrat, 'cause no Republican, conservative, would ever screw around with this unless it was for military reasons! Afte you set this mad equipt guitar on your lap. does your pecker point north?
Merry Xmass to all!

Denny Turner · Post by **Denny Turner** » 29 Dec 2004 8:37 am

Thank You Rick.

Aloha,
DT~

Wayne Cox · Post by **Wayne Cox** » 31 Dec 2004 9:29 am

RICK, a few years ago, Bruce Zumsteg & I did some experimentation with steel guitar pickups. One of the things we discovered was that when the gauss becomes too strong, the pickup turns into a microphone. Your design is different from any we tried but any chance of your MRI being too microphonic???
~~W.C.~~

Rick Aiello · Post by **Rick Aiello** » 31 Dec 2004 10:10 am

Any fully charged Rickenbacher Horseshoe or Fender Trapazoid/Boxcar ... is going to "pickup" ambient vibrations (non-string oriented) ...

Simply tap on the magnets or coverplate ... and you hear the tap thru the amp ...

I prefer to call these types of pickups "Vibrasonic" as opposed to "Microphonic".

The term "Microphonics" is usually associated with a loose coil ... and can be improved greatly by wax "potting" . Ya know ... The characteristic of speaking into the pickup and your voice being heard thru the amp ...

With these "3D" magnet systems (horseshoe,trap, etc) ... you are always going to have "Vibrasonic" characteristics ... its simply a function of Faraday's law. Even with the best wound "potted" bobbin ... you are gonna hear the non-string vibrations.

The stronger the magnets ... the greater the audible "Vibrasonics" ...

This may bother some folks ... but the "trade-off" of hearing ambient vibrations is welcome by many (but not all).

My cast aluminum Dustpans ... being 1 solid chunk of metal with integrated nut/bridge ... paired with a 500 gauss (midgap) H-Shoe ... is the most "Vibrasonic" machine I've ever seen.

With the gain turned up abit ... you can pickup the vibrations of touching the tuning pegs ...

Glorious to some ... annoying to others ???

All depends on what you want to hear ... and how you play.

WC ... to answer your guestion ... because of the directionality (mentioned above) of the field toward the interior cavity ... the "Vibrasonic" characteristics ARE LESS than with my H-Shoe or even a fully charged Ricky.

Once I get one permanently mounted into a pan ... and have anothe built for a pole piece bobbin ... I'll have a better indication of what characteristics this thing will have.

Hope that helped and didn't bore y'all too much on this festive day ...

Gotta go work on something ... watch for another

post soon

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Aiello's House of Gauss


My wife and I don't think alike. She donates money to the homeless and I donate money to the topless! ... R. Dangerfield

Rick Aiello · Post by **Rick Aiello** » 2 Jan 2005 4:19 pm

Should be singin' next weekend ...

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Aiello's House of Gauss


My wife and I don't think alike. She donates money to the homeless and I donate money to the topless! ... R. Dangerfield

Rick Aiello · Post by **Rick Aiello** » 9 Jan 2005 4:19 pm

Just finished puttin' her in my prototype dustpan ...

Sorry to tell y'all ...

But this is the Finest Pickup I've ever heard ...

Jason Lollar has just "raised the bar" so high ... I doubt even he can top this.

Jackie Anderson · Post by **Jackie Anderson** » 9 Jan 2005 4:46 pm

How 'bout with some Boxcar bobbins...?

Meanwhile, Rick, you are the one who keeps on outdoing himself!

Rick Aiello · Post by **Rick Aiello** » 9 Jan 2005 5:02 pm

Jack, these are them ...

He recently got some folks workin' with him in his shop ... and that freed up enough time to do two "prototypes" ... and he sent me one to mess with.

They are soooo "fine" ... that old design I had made (that we were gonna do for your Dually) ... was far to inefficient ...

PS These are alittle "rough looking" ... it's just a prototype.

They didn't need to be 1.5" wide ... that was just to fill my frypans bay ... the width only needs to be 1" actually ...

Less right hand obstacle ...

No pole piece adjustin' ... strings perfectly balanced ... the bass response is scarey ...

Phewwwwwww

[This message was edited by Rick Aiello on 14 January 2005 at 01:02 PM.]