Winds vs. Length

[TheGrateOz]

I know, I know it's preference right?

Seriously, I know there are many different bobbin types; some taller, some wider. Is there a reason that wind count is a more prevelant measurement for coils than wire length? Perhaps it's just easier to measure?

[big_teee]

I know, I know it's preference right?

Seriously, I know there are many different bobbin types; some taller, some wider. Is there a reason that wind count is a more prevelant measurement for coils than wire length? Perhaps it's just easier to measure?

Wire Length or Wire DCR?
I see another great debate in the making!!!
Good Luck,
Terry

[TheGrateOz]

Let's add DCR to the list then! =)

[salvarsan]

Windings counts tell you how to make the coil.
Wire length is what you get when you're done.

When you measure the DC resistance of a coil, you also determine
the wire length on the bobbin, assuming you know the wire gauge.

[Mark Hammer]

Certainly count and length mean something, but like DCR, don't be fooled by superficial numbers. For example, consider a Telecaster neck pickup. The polepieces are spaced a little closer together than a Strat, so the total circumference of any turn is juuuuuuust a bit less than a Strat, on a per-turn basis. For the same number of turns as a Strat coil, the total length and DCR will be different. Consider a P90 vs a Jazzmaster. The inner turns on the P90 start just a little further away from the iron core, due to the bobbin, compared to a Jazzmaster where the coil starts out right up against the alnico polepieces. The P90 is just a little taller than a Jazzmaster, so the outer turns on a Jazzmaster start to increase in length/circumference faster than they do on a P90. Now consider one of the PUs that somebody like our esteemed Mr. Lollar makes for a pedal-steel player, or even a SC pickup for a 7-string guitar, where the total length of any turn is immediately longer than what it would be on a conventional 6-string instrument.

Bottom line: Knowing the total length WILL give DCR (assuming the wire isn't stretched in the process of winding), but gives little indication of the number of turns that it took to get there, nor their relationship/proximity to the polepieces. So, knowing total wire length is probably very helpful for planning out your inventory needs if you are a manufacturer (X number of feet per spool), but doesn't really allow you to predict very much about the tonal or output properties of the pickup.

[big_teee]

Rick Turner said it best.
Not in his words, but its not rocket science.
You have to wind and test, wind and test, and then wind and test.
Great sounding pickups are no accident.
Great pickups are a product of all things considered, and lots of wind and test.
Anytime you change any item in the equation, you need to go back to the Wind and test method.
Turns, DCR and all are starting points, and also guides for repeatability!
Good Luck,
Now I think I will go, Wind and test!
Later,
Terry

[salvarsan]

.You have to wind and test, wind and test, and then wind and test.

How do you test your pickups?

[big_teee]

How do you test your pickups?

The old fashioned way.
I mount them in a guitar and play them.
Nothing technical here. I just try to get them to please my ears.
I am working on 3 Strat Bridge pickups right now.
I make changes on one, put it in play a day or so.
I make whatever changes I think I want on another one, then I swap.
I have been fooling with the baseplate also.
I try to document all the changes, then if I ever get what I like.
I try to have info where I can repeat the process.
I've heard of folks building pickups to specs, then selling them.
I couldn't think of selling anything that I hadn't a least tried in a prototype a few times first.
I don't know of any short-cut, for coming up with great sounding pickups?
Do You?
Later,
Terry

[Mark Hammer]

It is quite easy to make oneself a Danelectro-style body and attach a castoff neck purchased from a store for $20. You can leave a hole so that pickups can be quickly installed from the rear. For example, you could leave the pickup mounting ring in place, and simply slip a new HB into place and quickly attach it with the height adjustment screws.

I think one of the chief challenges to the testing aspect is being able to engage in quick comparisons under identical circumstances. Being able to swap out pickups quickly in the same guitar, without having to restring, or even alter control settings, can be a real boon this way.

[salvarsan]

The old fashioned way.
I mount them in a guitar and play them.

two points:

1. You can fool yourself into thinking something sounds better than it does.
2. Testing every pickup in a guitar limits your production volume.

The first point is an old observation and can result from something as ordinary as fatigue or a change in diet.

Barden, Fralin, and Lace have all commented about this and it's why they add a second set of ears for products under development.

The second point means that your production is limited by how fast you can swap pickups into a test guitar; they must command a higher price or the business won't support you.

For a production run of several dozen pickups, many builders here check DC resistance (at minimum) and inductance if they can -- it shows up the outliers without the tedium of installation in a guitar.

Then, knowing that if your pickups spec similar, they will sound similar, you can install one in five in a test guitar for your quality assurance.

The test guitar that quickly accommodates different pickup forms is a topic for another thread.

[big_teee]

Salvarsan:
I agree with everything you said.
That is the way to operate if your in business.
On my Strat bridge pickup tests, when I get one I think is worthy of production I will follow some of your OP.
Right now I'm still trying to satisfy the ears (Mine).
Rock on!
Terry

[TheGrateOz]

Thanks guys - I knew this was going to be a great conversation