Sunday, 4 May 2008

The Geo Mag Pick-Up (updated)

After successfully rewinding a broken Fender Jaguar Pick-Up, I decided to make one from scratch.
A pick-up kit, complete with bobbins, magnets, wire and polepieces just seemed to easy so I started to look around the house for supplies.
I found a bunch of these Geo Mag poles:



...and cut of the plastic:


There are two, extremely powerfull, Neodynium magnets on each pole. The one closest to the strings must be removed. When removed, the magnetic power on the "string-end" closely resembles standard Alnico magnets used for pick-ups.


I stripped 6 Geo Mag poles and attached them to a standard size bobbin, made from some very sturdy cardboard. I insulate the poles with tape to protect the coil wire from corrosion:



UPDATE:
I finished winding and ended up with 5000 turns and a resistance of 5,8 kohm. The coil wire was a bit loose so I gave the whole thing a nice dip in a mixture of 80% candle wax and 20% beeswax, heated to a temperature of about 60 degrees Celcius in a double boiler. I'm no expert, but there are plenty of tutorials out there on Pickup potting.
My boiler looks a little primitive, but it turned out fine. The coil wire is firm.



I installed the pickup in neck position and tested it through a PocketPod. At first it sounded pretty standard: Clear bell-like sound and so on. Then I noticed that the bassy notes has got a very distinctive snappy-sound to them. Also the pickup is almost noiseless, which I didn't expect :-)
All in all it's a decent pick-up with a unique sound and a lot of fun to make. The next one will be a bass model.

17 comments:

Niels Kaagaard said...

Hi. Any comments are wellcome !

Anonymous said...

Hej Niels. Jeg fik samme idé og søgte på geomags og guitar pickup og fandt din side. Har du mulighed for at lægge et lydeksempel op?

Niels Kaagaard said...

Hejsa. Jeg skal nok forsøge mig med et lydklip på et tidspunkt, men har ikke de store indspilningsmuligheder lige nu. Jeg venter nok til jeg har lavet en mere, så man kan høre den på forskellige positioner på guitaren.

Niels Kaagaard said...

...og jeg er da også åben for at låne et eksemplar ud.

Thomas B said...

Det er pænt af dig, men nu har jeg bestilt en rulle kobber, så jeg skal i gang med at vikle. Jeg kan sende et lydklip, når jeg (forhåbentlig) når så langt.

Niels Kaagaard said...

Det glæder jeg mig til at høre ! Tråden kan være lidt svær at finde til en rimelig pris i Europa. Jeg købte mit via ebay.uk (søg på 47 swg coil wire). 47 swg er samme tykkelse som 42 awg, som er standard tykkelse.

Thomas b said...

Jeg fandt et sted i Danmark (elektronik-lavpris.dk), der solgte 750g 0,05mm til 600 kr. + porto. Jeg vil lave to humbuckers med coil split, så jeg lægger stort ud ;-)

Er i øvrigt også ved at lave en guitar (halsen er dog genbrug) - det bliver en strat-agtig bastard med hollowbody....

DIY kan ikke rigtigt betale sig, men det er sjovt :-)

Niels Kaagaard said...

Spændende. Jeg vil også gerne lave en semi-hollowbody, men har svært ved at finde træ til toppen.

thomas b said...

Det samme her. Det bliver et underligt sammensurium af noget gammelt vellagret træ og krydsfinér - det er første gang jeg prøver et sådant projekt, så det har nok mest karakter af at være en stiløvelse.

Christian K. said...

Hi,

a very goog thread.
Here is my blog about my homemade guitar.

http://guitarbuilder.wordpress.com/

I will build my own humbucker Pickups and use geomag... good idea.

one question:
is it possible to use the geomag for humbucker building ?

The small magnets have north and south pole, ok.

Is it right when i turn the small magnetics 180° in a humbucker, but onliy for one row (6 item)?

Thanks bye
Chris

Niels Kaagaard said...

Hi Christian

Thanks for the Comment !

The Geomag-magnets have got a north and south pole, and I think You can use them for humbucking pickups.
You need to make the Humbuckers "RWRP” : reverse wound-reverse polarity.
So You must wind the coils in different directions and place the two rows of magnets in different polarity.

I'll keep an eye on your blog ;-)

Christian K. said...

Hi Nils,

i will find out, where is the north and where is the south pole of the magnet.

How can i do the this ?

Use the geomag like an compass-neddle with a thin wire in the midle ?

Why i must wind the coils in different direktions ?

The different polaity i agree.

Bye
Chris

P.S.
I´ll will keep an eye on your blog, too ;-)

Christian K. said...

Hi,

have a look at this page about the winding direction.

http://www.stewmac.com/FreeInfo/Electronics/Pickup_building/i-5961.html

Bye

Niels Kaagaard said...

Hi Christian

I was sticking to the information on http://en.wikipedia.org/wiki/Humbucker
...but I´m not sure if one of the coils really needs to be reverse wound.
I think You can use a any cheap compass to determine the North and South of the magnets.

Christian K. said...

Hi Niels,

is a soundfile from your pickup available ?

Check my blog with the new´s about my drawing ;-)

Next week is winding time....

Bye

Niels Kaagaard said...

Hi
Sorry I haven't made a soundfile yet. I'll post it when I have one ready.

Manfred Christiansen said...

træ til top blev der spurgt om noget tidligere:
basslab
woodworks

Jeg har selv bygget en el-spade og to akustiske (1 archtop, 1 klassik) er igang med en EUB (electric upright bass) med piezo pickup og har planer om en ES-type halvakustik.

Manfred
www.x-iansen.dk
(se også min pladespiller med en tonearm lavet af et sammenrullet stykke avispapir)