Blade Style Pickup - Ceramic Magnet Orientation

[rjb]

This may be going against the grain, but I've always believed that a nice, bright and clear tone makes your bass sound great. A thick and dark tone makes the band sound great. I run by treble and mids flat and boost my bass. I always play flats.

AFAIK, isn't that standard mixing/recording philosophy? Cut highs on the bass and lows on the guitar to improve instrument separation/clarity by giving everyone their own restricted territory in the audio spectrum? (Oversimplifying, I know- I'm just a dilettante.)

It also seems to me like you guys are saying that the return strip is superfluous. Just out of curiosity, is there any reason for a return bar on the Peavey pickup?

It appears that Peavey's reason was to increase the magnetic field on the topside of the pickup.

There was a magnetic return strip of iron laid flat across the bottom of the pickup and magnetically attached to the bottom edges of the pickups. This iron kept the magnetic field from forming on the bottom of the pickup identical to the top field, so the field on the topside was greater than of that of the pickups like Gibson, (without magnetic returns).

Since we've already established your sanity , here's a slightly messy experiment you might consider.
(Disclaimer: I've never gotten around to trying this myself, but would be interested in the results)

Space the magnets 1/2" apart with plastic standoffs or copper wire or some other method that uses a minimum amount of non-ferrous material. Suspend the assembly in a clear container filled with mineral oil and #0000 steel wool fibers and view the magnetic field. Try again, using two magnets with a return strip. How is the magnetic field affected?
Ref 3D Magnetic Field Viewer

-rb

EDIT: DK posted #30 while I was writing this.

[Freekmagnet]

Since we've already established your sanity , here's a slightly messy experiment you might consider.
(Disclaimer: I've never gotten around to trying this myself, but would be interested in the results)

Space the magnets 1/2" apart with plastic standoffs or copper wire or some other method that uses a minimum amount of non-ferrous material. Suspend the assembly in a clear container filled with mineral oil and #0000 steel wool fibers and view the magnetic field. Try again, using two magnets with a return strip. How is the magnetic field affected?
Ref 3D Magnetic Field Viewer

Haha!

I'm pretty patient, and when it comes to things like winding a pickup, I really don't mind if I have to do something a hundred times to get it right. However, the process you just described is way out of my register.

AFAIK, isn't that standard mixing/recording philosophy? Cut highs on the bass and lows on the guitar to improve instrument separation/clarity by giving everyone their own restricted territory in the audio spectrum? (Oversimplifying, I know- I'm just a dilettante.)

I'm glad you bring this up because although I may come off a little overzealous, I guess I'm just reacting to some of my own issues. It just seems like on a lot of these forums and stuff some bass players get really preoccupied with "cutting through the mix" or "getting enough bite out of my tone." I'll watch a demo on YouTube of a bass I actually want to hear, but the reviewer has the treble all the way up and his mids cut and it just never represents a real world bass playing sound. And you guys are right - a pickup should have sufficient brightness to have a well-rounded bass tone and shouldn't be too dark and muddy, even if that's something you're striving for. Phew, now I can step off of my soapbox.

Sometime in the next couple of days, I'll get those magnets out. I have some Forbon sheets here. I think I'll try some of that for the magnet bobbins. I used the Lexan because it was easier to cut, but it seems like the Forbon is a little more forgiving in the clean up. Those magnets are really brittle, so I think it'll be easier for me spot any potential snags when it comes time to install the magnets. We'll see. I'll post a picture when I get those bobbins cut.

[Freekmagnet]

Well, I knocked these out today. They came out OK. I'm using a 1/8" spiral cutter to cut my slots, and the magnets are maybe a teeny weeny bit smaller than 1/8". They're not sliding around, though.



I'm trying to decide if I should add those little eyelets for soldering the leads or if I should just solder my pigtail directly to the pickup wire. I think either way would be fine.

@big_teee - I've been giving it some thought and perhaps you will be relieved to know that I do have a Plan B that does involve some of those off the shelf parts you posted earlier. However, it also involves this stock part as well...

[big_teee]

Freeky, You're going the opposite direction from me on the T-bird Pickups.
I like deeper covers, that allow more bobbin height, with less metal.
A inside bobbin height of .4" or more is what I like, but YMMV.
That's why I stick with the ugly black plastic covers.

I recommend putting the eyelets on, but flush on the inside with the bump on the outside.
Solder the hookup wires on the outside across the eyelet, just like a J-bass pickup does, on the ends, but without using a center hole.
http://www.stewmac.com/freeinfo/i-5978/01eyelets.jpg

Also tonally with bass pickups when you go to winding?
A lot of times IME less wire = More tone, and less mud!
GL & Have Fun!
T

[SpareRibs]

[QUOTE=Freekmagnet;412891]
I'm trying to decide if I should add those little eyelets for soldering the leads or if I should just solder my pigtail directly to the pickup wire. I think either way would be fine.

Hello,
Solder the pigtail directly to the pickup wire. If you extend the wire to the eyelets the wire will be vulnerable to breakage. If it is soldered directly to the pickup wire it will be protected by the tape, as well as wax should you decide to pot them.

[big_teee]

Both methods have merit.
If you don't want them all taped up, use eyelets.
Only Cazillions of fender pickups have been made that way!
T

[David King]

Knock the sharp corners off the ceramic magnets on some silicon carbide sandpaper before you wind or wrap a layer of electrical tape over the ends to protect the wire insulation.

[Freekmagnet]

Knock the sharp corners off the ceramic magnets on some silicon carbide sandpaper before you wind or wrap a layer of electrical tape over the ends to protect the wire insulation.

Cool. Will do. Will Kapton tape work?

Thanks all you guys for your suggestions. You've all been a really big help.

None of this project is turning out to go in the direction I expected, but considering I've never built a pickup before, I can't say that I know what to expect. As usual, I'll piddle around with a few different approaches until I find the one that works - not that this one doesn't work - just checking out options.

I'm going to order some plastic bobbins and some different sized magnets and see how those will work for this. Prolly order one or two of those T-Bird covers as well.

[David King]

Kapton tape is good stuff. Philadelphialuthier.com is another source for metal T-bird covers. With ceramic magnets less is more when experimenting with number of turns. Have fun with it but when it come to evaluating what you've got it pays to keeps a known pickup around for comparison. An early 60's J pickup or a decent Bartolini will tell you a lot about what you have.

[Freekmagnet]

Kapton tape is good stuff. Philadelphialuthier.com is another source for metal T-bird covers. With ceramic magnets less is more when experimenting with number of turns. Have fun with it but when it come to evaluating what you've got it pays to keeps a known pickup around for comparison. An early 60's J pickup or a decent Bartolini will tell you a lot about what you have.

Cool! Thanks.

So, going back to the T40, would say 3500 - 4000 turns be a good place to start for ceramic blades? A Jazz has like what, 9000 - 10000 turns? I put a little counter on my machine, and I have an ohmmeter, so I should be alright.

[big_teee]

Hey Freek, if you can give the bobbin core dimensions, maybe we can do some calculations.
Inside Bobbin core , Length, width, Height, Flange ?
T

[SpareRibs]

Hello,
Floral tape is very good to. It is about the same composition, comes in various widths, and colors. What the downfall is, is that it isn't labeled by one of the, Guild of high price suppliers.

[Freekmagnet]

Hey Freek, if you can give the bobbin core dimensions, maybe we can do some calculations.
Inside Bobbin core , Length, width, Height, Flange ?
T

Wow, gosh thanks, big_teee - that's awful nice. However, I'm not quite ready to wind yet. I ordered some of those plastic bobbins and some more ceramics to fit them. I'm think I'm going to mess around those a bit before I make any big decisions about how to proceed.

Were you speaking the dimensions of the bobbins I built yesterday?

That being said, and I'm speaking from complete ignorance here, are you calculating the amount of wire wound around the bobbin? If you want to save time explaining, if you point me in the direction of the why, where and how we'd be making these calculations, I assure you that I will read it thoroughly.

[big_teee]

You can do it.
Coil Estimator
Find a pickup similar and alter the data to see what fits whatever bobbins you have.
T

[Freekmagnet]

You can do it.
Coil Estimator
Find a pickup similar and alter the data to see what fits whatever bobbins you have.
T

OK, I get it.

So, just for the sake of example lets take these T40 specs.

If I have 3750 turns of #42 measuring 3.8K. I have another bobbin with different dimensions, and I want something in the same ballpark, I am looking to match the resistance, correct?