The reference thread for newbies!

[David Schwab]

I tried the PU on a chinese precision clone. Well, it's sweet.
Low on volume, maybe due to the low DCR (6KOhm), but clear, punchy, lots of harmonics. Beef and rough like a precision PU should be.
No hum at all.

With a K&K preamp and a bit of gain, it's BOOOM

That's a much better way to get a clear tone. How do you think many active pickups work?

A 6K pickup will sound better than a 10K pickup as far as clarity goes. If you want more volume increase the inductance.

[David Schwab]

Remember, traditional p-bass PU have 10.000 turns per coil!

No.. about 10,000 turns total. Not per coil. You can't get 10,000 turns on 42 on that bobbin!

http://www.seymourduncan.com/support..._a_6.shtml#319


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[Biarnel]

Let's say one wind around a P bass bobbin is about 5 inches (bobbin is 2 inches wide X2).

Ehm!
I'm going nuts in this metric/inches conversions...
How can you say a P bass bobbin circumference is 5 inches? That will be 127mm.. I had only 70mm circumference!

Geez, the P-BASS COIL MISTERY!!

[David Schwab]

Ehm!
I'm going nuts in this metric/inches conversions...
How can you say a P bass bobbin circumference is 5 inches? That will be 127mm.. I had only 70mm circumference!

Geez, the P-BASS COIL MISTERY!!

I probably made it too big. But I looked at one here and the bobbin is 2" wide (50.8mm). But the four poles are 1.625" wide (41.275 mm). So double that and we have about 3.25" (85.55) plus what ever the thickness of the poles are.

So my measurements are too big.

Still, I make a pickup where I wind 1500 turns of 42 awg on a coil form 3.25 (85.55mm) wide. That's the actual core. It's .125" thick (3.175mm). I just wrapped a piece of wire around it, and I got a piece 8" long (203.2mm). Multiply 8 by 1500, and I get 12,000 inches. Divide that by 12 and I get 1,000 feet. Multiply that by 1659 (Ohms) and you get... 1,659K. I ended up with 1,471K, but there you go.

So 1500 turns on a 3.25 former gets me about 1,500K.

Are you sure you did 7,500 turns?

[Biarnel]

I probably made it too big. But I looked at one here and the bobbin is 2" wide (50.8mm). But the four poles are 1.625" wide (41.275 mm). So double that and we have about 3.25" (85.55) plus what ever the thickness of the poles are.

Uh, I think I nailed the main misunderstanding here.
Ok, p-bass standard 2-mags-per-strings coil give 38mm in width, double it, add the double of the mags thickness (5mm), we have 86mm each turn.

BUT!
My mags are 10mm, as I stated before, and I use one of them each string. This way, I have a thicker but less large coil: 28 mm in width, double it, add the double of the mags thickness (10mm!), we have 76mm each turn.

Can this be the main thing? Do you agree?
Should I stick with 5mm mags and stop bothering everyone??

Are you sure you did 7,500 turns?

Sure. My ugly homemade winder has a mechanical counter, a stroke counter actually, and BANG BANG BANG it can't miss a turn. It's so awfully loud..

[GlennW]

I still think his counter is off; if not that maybe his DMM, but that seems less likely with the low output he's getting.

[Biarnel]

I still think his counter is off; if not that maybe his DMM, but that seems less likely with the low output he's getting.

You can't switch off a mechanical stroke counter
It's a coil size thing, read my reply to David.

[madialex]

Not at all

You are not bothering any of us, at least not me anyway. I do understand the size coil you have now. I am however still perplexed about the thin tone you were getting. If I remember right, Jason Lollar built a pickup for a six string, humbucker if i remember, it has a single coil for each string, wound around 1 magnet each. I tried this one time just for giggles and it actually had pretty good output, even with the small coil size you have it shouldnt be thin, maybe a lot more high end than low end but not thin i dont think.. I am going to wind a coil tomorrow with only 3 5MM magnets which is only 5MM longer than yours but still use 7500 turns like you did and see what the tone is like. I found my old split coil proto I did way back so i can use 1 side of it for this. We'll see and report back my findings.........

[David Schwab]

You can't switch off a mechanical stroke counter
It's a coil size thing, read my reply to David.

But.. they only wind 5,000 turns on a stock P-bass bobbin. That fills up the bobbin.

Your photo doesn't look like 7,500 turns. It looks like 2,000 maybe. How tall are the bobbins?

But either way, one of my favorite pickups I wound was a P bass with only 500 turns per coil.

[EtLa]

a coil is approx 7cm of circumference; not more than that, because it's 2-strings, not 4.

7cm cf., 7500 turns, it's 52500cm, so it's 1722ft approx.
With a AWG42 the table says 1659Ohm per 1000ft.
My coil is 1800Ohm. More or less what that table says.

Am I doing well 'til now? I think I'm messing up something stupid.

you have 2 half circumference so we can say you have one circumference
2 x 3.14 x 5mm = 31,42mm
If it's a PBass string space(but only one magnet)
19mm x 2 = 38mm

Total ~69mm

But don't forget that your coil is getting wider and at the end you have more resistance per turn
With Zielgler Pick-up calculator http://pickups.myonlinesite.com/programs.php I get 3642 ohms for 7500 turns

[DrStrangelove]

Coil estimations

The mags are 10mm dia.
The center of the mags are 18mm far.

Thanks.

So our core dimensions are:
Length 28mm (edge to edge)
Width 10mm
Height 14mm (assuming 3mm thickness flats and 20mm magnet length)

The first winding length is 6.74mm ~7cm

Every simulation I do for 7500 winds of #42 single build wire
gives 2650 ohms at a 100% fill factor (never happens), and increases
to 3200 ohms at a 62% (average scatter wind) fill factor.

This is confusing.

Have you checked your meter battery?

-drh

[SteikBacon]

Maybe you Biarnel should take a picture of the coil next to something we can measure with. Both in inches and mm. This turns out to have lots of info about basspickups. Great.

[Biarnel]

Your photo doesn't look like 7,500 turns. It looks like 2,000 maybe. How tall are the bobbins?

The bobbins are 9mm tall. I mean, the room for the windings is 9mm. I made that flatwork way too thick and they sucked up the 15mm tall mags

But either way, one of my favorite pickups I wound was a P bass with only 500 turns per coil.

Uhm.. AWG42?
Activated/buffered, I hope!

[Biarnel]

Every simulation I do for 7500 winds of #42 single build wire
gives 2650 ohms at a 100% fill factor (never happens), and increases
to 3200 ohms at a 62% (average scatter wind) fill factor.

This is confusing.

This is one of the most confusing thread of my forum reader career

Have you checked your meter battery?

As I wrote somewhere in this thread, my counter has no battery.
It's a mechanical stroke counter. Spring operated.
On the spinning baseplate there is a metal rod that hits against the stroke counter's arm, increasing by 1.
In case of malfunction, it may LOSE a turn, or two, or 20, but it can't simply count MORE turns.

The problem is somewhere else

I think lots of people here lose many of my posts because they read in "threaded" view and not in linear view.

[Biarnel]

I just wound a J-bass 4 string pickup.

Well, same problem, again.
I wanted it to be dual coil: 2 coils, 2 string each, 1 mag per string, 10mm dia, 15mm tall.
The coil are side by side, and in a typical jazz bass enclosure.

The PU with the coils in series should read 7kOhm DCR.

Well... I gave it 13.000 turns PER COIL. Now I have 7kOhm DCR when in series.
It sounds sweet and clear.

BUT!!!
The coils are SO FAT (13.000 turns..) that they don't fit inside the jazz bass enclosure. I had to push hard and bend the plastic... not a nice thing to do.

I begin to think that they sold me AWG30 or 25

Any ideas? Why my windings are so low on DCR?