Winding A Bass Pickup

[Geo]

I'm winding a bass pickup. I have wound one other pickup, a humbucker. I got the bobbin turning a little too fast, I think, and the wire broke. Here's my question--should I just solder the broken wire ends back together and keep winding? Or should I start over?

I think it will work to solder the ends. I would be sure to heat the joint for a long time so that the enamel melts, etc. If it works for soldering the start and finish of the coil to their respective leads, it should work here... but I would like some other opinions. Thanks.

[black_labb]

I'm winding a bass pickup. I have wound one other pickup, a humbucker. I got the bobbin turning a little too fast, I think, and the wire broke. Here's my question--should I just solder the broken wire ends back together and keep winding? Or should I start over?

I think it will work to solder the ends. I would be sure to heat the joint for a long time so that the enamel melts, etc. If it works for soldering the start and finish of the coil to their respective leads, it should work here... but I would like some other opinions. Thanks.

how far along are you? what are you using to wind and how much of a hassle to do? ive always restarted, but my breaks have been silly thigns (unwinding 150 winds by hand to find where i went off the bobbin slightly, found it after way too long and put the wire on the ground due to lazyness, and then forget to make sure i wasnt standing on it when i started up again) it also depends on what the chances of you breaking it again are.

i have to ask, what are the common winding specs for basses, im looking to make myself a bass when i get some time and finish my current guitar. what gauge wire do you use, what resistance and what type of magnets? are they similarly wound to guitars or do you use lower ohms to get a more even curve? do you use a lower gauge wire or just less turns? thanks

[SwedishLuthier]

Soldering the wire is possible. Be careful so that you do not create a big blob of solder. It will make the coil bulge out. You must also insulate the joint or if might rub against the surrounding wire and create a short out.

The most common problem with breakage isn’t how fast the coil spins. I wind my pickups 1400 rpm. The most common reason is too high wire tension or some rough spot on the bobbin catching the wire.

Specs for bass pickups are harder to find compared to guitars pickups. I can make a quick PDF with the bobbin specs but I do not have the exact turn count for either P or J bass. PM me or post here if you would like to have those

You can have a look at Fralin/Duncan/other supplier to find out the DC resistance values of their pickups. Me I always wind to turn counts but DC resistance gives a hint about how much to wind anyway.

According to Fralin the Vintage specs are:

J-bass:

42AWG wire

ALNICO5 magnets

Neck 8 Kohms

Bridge 8.5 Kohms

P-bass

42AWG wire

ALNICO5 magnets

Wound to 10 Kohms (both coils in series)

If anyone have the turn counts for vintage P and J-bass pickups, please share.

[black_labb]

Soldering the wire is possible. Be careful so that you do not create a big blob of solder. It will make the coil bulge out. You must also insulate the joint or if might rub against the surrounding wire and create a short out.

The most common problem with breakage isn’t how fast the coil spins. I wind my pickups 1400 rpm. The most common reason is too high wire tension or some rough spot on the bobbin catching the wire.

Specs for bass pickups are harder to find compared to guitars pickups. I can make a quick PDF with the bobbin specs but I do not have the exact turn count for either P or J bass. PM me or post here if you would like to have those

You can have a look at Fralin/Duncan/other supplier to find out the DC resistance values of their pickups. Me I always wind to turn counts but DC resistance gives a hint about how much to wind anyway.

According to Fralin the Vintage specs are:

J-bass:

42AWG wire

ALNICO5 magnets

Neck 8 Kohms

Bridge 8.5 Kohms

P-bass

42AWG wire

ALNICO5 magnets

Wound to 10 Kohms (both coils in series)

If anyone have the turn counts for vintage P and J-bass pickups, please share.

thanks for that, i wasnt looking for any specific specs. ill be making my own bobbins any way. i was just curious wether its a similar wire and dc resistance with different magnets, or if it was something different.

[Geo]

I appreciate the replies.

I measured the DCR of the pickup on a friend's Squier P-Bass (a decent instrument I guess), and it was about 5.8k. When I saw that, I figured there wasn't anything "special" about bass pickups (look at the different shapes--humbuckers, split on a P-bass, thin single coils like a Jazz bass). Mine is sort of a P90--a wide bobbin, 8 screw polepieces. There will be a bar magnet underneath the bobbin on one side of the screw-ends, and an iron spacer on the other side to "help spread it around".

A related question... what would be the effects of using a steel baseplate for the pickup? Would it "help" the magnetism or dilute it? Since it's not a humbucker (w/different magnetic poles being used by the pickup), I think it should be fine.

I'm inclined to solder the ends. SwedishLuthier--thanks for the point about the size of the solder blob. I hadn't thought of that.

I'm not sure how far along I am. I'm not counting windings--just winding till the bobbin is full. I gave myself plenty of bobbin room, so it should have a good DCR. I would say it has between 200 and 500 windings on it now? My system is "ghetto"--the bobbin is fixed to a plate w/dowel which goes in a hand-drill chuck. The drill is clamped down to the bench. The roll of wire hangs a few inches away on a broken drumstick which is also clamped down to the board. I have to be careful with the drill speed--it got a little too fast, I think, which is why it broke. I set the drill throttle "low" so that the speed is more controlable.

[SwedishLuthier]

I figured there wasn't anything "special" about bass pickups

You are right. There are a lot of details that differs but there are no special “magic” things that make a pickup construction more or less suitable or unsuitable as a bass pickup. Having said that I have never worked with a P-stylish pickup for a bass. Might be very interesting. The closest thing to this that I can think of (please correct me if I’m mistaken) are those Gibson EB-0 pickups. With your design you have an option to add a second bar magnet (substituting the metal spacer) if the output is too low with only one magnet. Thinking about it you maybe should start with two magnets. The steel bar will have an opposite magnetic pole butting up to the screw compared to the magnet. Having a second magnet doing that will not sound very good. The current induced in one half of the coil will partly bee countered by the current induced in the other half, pretty much like in a humbucker with the coils out of phase.

A related question... what would be the effects of using a steel baseplate for the pickup? Would it "help" the magnetism or dilute it? Since it's not a humbucker (w/different magnetic poles being used by the pickup), I think it should be fine.

I have tested it with a P90 and the result was less than satisfying. The magnetic field always takes “the shortest way”. A magnetic field will always follow metal (steel) instead of air gaps if there is metal in close proximity of the magnetic pole. And the steel plate in contact with the two bar magnets pulled the magnetic field down through the steel plate leaving only a fraction left to go up through the pole screws and the air back down to the magnets. The output was really poor and the sound nothing to write home about…

Please report about how the pickup sounds.

[Samba Pa Ti]

what about using a brass or copper plate instead, wouldnt this aim all the magnetic field up (using magnetic pole pieces), ive got a telecaster bridge pickup with a brass plate on the back and i always wondered why it was on there.

Edited May 31, 2007 by Samba Pa Ti

[Geo]

Thanks for the replies. I have some aluminum, so I may use that for the baseplate since it's totally non-magnetic. I suppose brass or copper would work too, but I'd have to buy that.

"With your design you have an option to add a second bar magnet (substituting the metal spacer) if the output is too low with only one magnet. Thinking about it you maybe should start with two magnets. "

I actually re-read Melvyn Hyscock's description of a P90 and realized it has two magnets, so I will definitely go with that. I have three more cheapo single-coil pickups with bar magnets underneath that I can canabalize if necessary. I hadn't thought about the proposed spacer taking on an opposite polarity, but duh, now I get it. I really appreciate your input on this.

I've put several thousand turns on the coil after soldering the break. I won't know if the fix worked until it's done and I go to measure the DC resistance. I'm not sure what I will do for a pickup cover. I have a block of mahogany left over from a neck blank, and if I can borrow a router, I may try to make a cover from it.

It will be a while before this bass is done, but I'll report on the tone when I can. I'll only have guitar amps to play it through for a while, until I build a bass amp.

[black_labb]

Thanks for the replies. I have some aluminum, so I may use that for the baseplate since it's totally non-magnetic. I suppose brass or copper would work too, but I'd have to buy that.

"With your design you have an option to add a second bar magnet (substituting the metal spacer) if the output is too low with only one magnet. Thinking about it you maybe should start with two magnets. "

I actually re-read Melvyn Hyscock's description of a P90 and realized it has two magnets, so I will definitely go with that. I have three more cheapo single-coil pickups with bar magnets underneath that I can canabalize if necessary. I hadn't thought about the proposed spacer taking on an opposite polarity, but duh, now I get it. I really appreciate your input on this.

I've put several thousand turns on the coil after soldering the break. I won't know if the fix worked until it's done and I go to measure the DC resistance. I'm not sure what I will do for a pickup cover. I have a block of mahogany left over from a neck blank, and if I can borrow a router, I may try to make a cover from it.

It will be a while before this bass is done, but I'll report on the tone when I can. I'll only have guitar amps to play it through for a while, until I build a bass amp.

sounds like were both in a similar boat, but im working on a guitar.

[Geo]

Cool... are you building an amp too? If so, it better be a tube amp, or I'll break your guitar strings!

[SwedishLuthier]

what about using a brass or copper plate instead, wouldnt this aim all the magnetic field up (using magnetic pole pieces), ive got a telecaster bridge pickup with a brass plate on the back and i always wondered why it was on there.

Brass, copper and aluminium isn’t magnetic and thus will not affect the magnetic field at all. The brass or copper plate under a tele pup is actually brass or copper PLATED steel. The steel plate under a rod magnet type pup helps to direct the magnetic field up against the strings. For FEEM simulations of the shape of magnetic field have a look here (courtesy of Steven Kertin of SK Guitars). A steel plate in a P90 type pickup would like I wrote before almost “short out” the magnetic field. No good idea. There are ready made brass P90 base plates available but I see little or no need for them. I don’t use base plates for my P90s.

I have three more cheapo single-coil pickups with bar magnets underneath that I can canabalize if necessary.

Just pay attention on the polarity of the magnets. Those SC type pups with bar magnets often have the polarity “upwards” against the steel slug pole pieces, going through the thinnest part of the magnet as opposed to the traditional A5 magnets that have the polarities running through the thicker side (not lengthwise thou). If you are making a custom bobbin that will not be a problem. Just place the magnets “standing up” and you are good to go. I have an old cheapo HB that uses four (!) ceramic magnets butting up against fixed pole pieces in exactly that manner and that HB doesn’t sound bad at all.

[black_labb]

Cool... are you building an amp too? If so, it better be a tube amp, or I'll break your guitar strings!

no im not, but i am thinking i may at some stage, but i dont know too much about elecvtonics, i may make a pedal and see how that goes then decide if i enjoy the electronics. i am prett psyched on my wiring design, but i cant see myself designing the amp due to the complexity.

when i get some time id like to make an amp though, but im rpetty busy with university and such

[Geo]

We really are in the same boat! I'm a college student too.

I actually learned tube electronics pretty quickly. I find it easier to understand than solid-state. Building your own amp is almost as rewarding as building your own guitar. Also, you don't have to design your own... just copy a classic Fender, Marshall, etc.

Swedish Luthier, thanks for the info. I have some aluminum, so I may use that for a base-plate.

[Samba Pa Ti]

Brass, copper and aluminium isn’t magnetic and thus will not affect the magnetic field at all. The brass or copper plate under a tele pup is actually brass or copper PLATED steel. The steel plate under a rod magnet type pup helps to direct the magnetic field up against the strings. For FEEM simulations of the shape of magnetic field have a look

very informative, like i said i always wondered this and i guess now i know : )

[black_labb]

We really are in the same boat! I'm a college student too.

I actually learned tube electronics pretty quickly. I find it easier to understand than solid-state. Building your own amp is almost as rewarding as building your own guitar. Also, you don't have to design your own... just copy a classic Fender, Marshall, etc.

Swedish Luthier, thanks for the info. I have some aluminum, so I may use that for a base-plate.

ive been slowly building up to the idea of making a amp. might have a go at it during the summer holidays (im in australia, so its your winter). im not too big on electronics, might have a go at it with a friend or 2 who would be interested.

[Geo]

slowly building up to the idea of making a amp. might have a go at it during the summer holidays (im in australia, so its your winter). im not too big on electronics, might have a go at it with a friend or 2 who would be interested.

Cool.... warning, it's addictive.