"Flatpups" pickups?

[Jason Rodgers]

Have you seen these? Flatpup news. A guitar builder friend mentioned them to me. Like sidewinders that got ran over!

Anyone heard them? This is very clever.

[Mark Hammer]

No idea what they sound like, but I imagine this is a good solution for folks who might want to add a pickup without cutting a hole or routing.

[jason lollar]

Definately has some demand for that after barcus berry quit making thier .25 tall pickup alot of people used on dobros. I have made some pickups with that low of a profile- there are alot of hoops to jump through on something like that to get a consistant and clean product with typical output and bass response.

[Mark Hammer]

I have a pre-war Kalamazoo KG-21 I've been trying to build a pickup for, for years, without a great deal of success. It has about 5/16 clearance between the strings and body up at the end of the fingerboard. Something like this might be just the ticket.

[rjb]

I haven't heard them in person, but there's a bunch of demos on YouTube.
The ones I've checked out sound pretty darn good.

The basic design is one that made me smack my head and say "Why didn't I think of that?"
It's on my hobbyist's list of things to copy... some day.

I've poured through the site, and admire the way the designer handled the mechanical details-
from the hookup wire terminations to the various frames, pickup rings, and covers.
In the photos, many of the pups are posed with hand-made jewelry; I bet having a background in metal smithing doesn't hurt.

The site seems to provide enough technical information to more-or-less "reverse engineer" the electrical designs....
Note that the iron core is punched through to hold the disc magnets, and the coil windings (partially) cover the magnets.
I wonder if alternate configurations with the windings parallel to the strings might yield interesting results?

I'm also intrigued by the pickups that are voiced for bronze strings-
I've never before seen external "pole shading" magnets used to reduce B & E string output.

Neat stuff.

[rjb]

I have a pre-war Kalamazoo KG-21 I've been trying to build a pickup for, for years, without a great deal of success. It has about 5/16 clearance between the strings and body up at the end of the fingerboard. Something like this might be just the ticket.

I've got a similar situation with an old Harmony Patrician.
I tried converting a DeArmond soundhole pickup for pickguard mount- it fits, but is too hot that close to the strings.

The Flatpup MR neck pickup is 5 mm (.197") and the bare pickup is 4.5 mm (.177") thick.
Should fit, but I wonder if the magnet pull would be too strong- looks like a row of neo's.

An alternative might be to stick a taller pickup to the body with foam tape, closer to the bridge-
say, between the f-holes.

[the great waldo]

Hi Rjb
Hi All
I know the guy that makes these pups. Elmar. He's a very nice chap who kind of stumped me as I was trying endlessly to make super thin Jazz pups by cutting down normal bobbins using neodym magnets etc. I found one of his pups in the shop where I work and was surprised. The basic idea is sidewinder humbucker coils with a p90 magnet circuit. The first ones were a bit Heath Robinson but worked well, I kicked myself for not thinking about it before. Elmar came up with a good idea to adjust individual string sensitivity by moving a reverse polarity magnet towards or away from the pole magnets. (I think this must be what Schaller was doing on their jazz pickups schaller-guitarparts.com.ua ) It made me think again that it is a good idea to step back sometimes from what one is doing to avoid getting into a short sighted rut. I wish Elmar all the best. The pups work well and it's nice to see someone taking a new approach on an old idea and they look good too.

Cheers

Andrew

[Mark Hammer]

I don't know if strong magnetic pull is necessarily an issue here. Keep in mind that we normally eschew strong magnetic pull on the basis of it interfering with sustain. However, the "classic" jazz archtop sound is often one where the post-pluck decay is actually fairly rapid. In a sense, strong magnets might simply exaggerate what we rely on a floating rosewood/ebony bridge to do in the first place.

[Mike Sulzer]

Yes, neos under the string provide all the fixed field necessary. You need a high permeability material such as steel to help bend the magnetic flux coming down from the vibrating string and guide it through the coils. This is somewhat harder to do in a thin rather than a thicker coil structure, and so more flux is probably lost than in a standard sidewinder. A key thing to determine would be how wide to make it: how wide would it have to be before the turns at the outside are not adding much to the signal?

I don't know if strong magnetic pull is necessarily an issue here. Keep in mind that we normally eschew strong magnetic pull on the basis of it interfering with sustain. However, the "classic" jazz archtop sound is often one where the post-pluck decay is actually fairly rapid. In a sense, strong magnets might simply exaggerate what we rely on a floating rosewood/ebony bridge to do in the first place.

[elmar flatpup]

Hi folks, I googled for 'flatpup' and found this thread. I appreciate your kind words :-) btw, the iron core isn't punched through since you want to split and bend the magnetic flux into the core. For those who want to give it a try, make sure the core tin is properly isolated to prevent shortcuts from the coil to the core.

[Mark Hammer]

Hi Elmar,
Kudos for your good work. And welcome here!
A question: Do you produce anything that can be used as a "floating" pickup attached to the end of a fingerboard?

[elmar flatpup]

Thanks Mark! Yes, there is a floating pickup version, although I usually don't offer it.

[rjb]

btw, the iron core isn't punched through since you want to split and bend the magnetic flux into the core.

Oops, guess I misinterpreted something I thought I saw.
Plus, I thought your design might be a flattened version of this:
https://docs.google.com/viewer?url=p.../US3902394.pdf

Thank you for generously providing that design information.
Feel free to stop by, anytime you feel like revealing more of your trade secrets.

[Jason Rodgers]

Thanks for jumping in, Elmar. I suppose it's a good idea to google yourself from time to time and see what pops up. Glad you found us.

Since you're telling us all about the Flatpups: Aside from the fact that thin pickups can be quite useful in certain applications, what inspired you to pursue the refinement and production of your design?

[rjb]

The first ones were a bit Heath Robinson...

I had to look that up.
Oh, I see- you meant "Rube Goldberg".