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Topic: Fender D-8Professional |
Dave Harmonson
From:
Seattle, Wa
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Posted 3 Jan 2007 7:14 pm |
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I'm a new convert to the straight steel and I love trying to figure out the puzzle. The double 8 pro I have has trapezoid pickups and the front neck is alot brighter than the back neck. Can anyone tell me if this is supposed to be that way, and if not, what I can do to match them up better?
Thanks,
Dave  |
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Gary Lynch
From:
Creston, California, USA
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Posted 3 Jan 2007 8:12 pm
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There could be a number of issues. One is the pickup itself.
Why do Vintage Fender Pickups Die?
After many years of use, Fender pickups die much more regularly than any other brand of pickups. Even Gibson pickups from the 1930's don't die like Fender pickups from the 1950's. Actually, the reason has to do with the design and materials of Fender pickups themselves.
Since the windings of older Fender pickups are in direct contact with the magnets, this has caused some problems. With time, the magnets seem to chemically react with the windings/insulation, causing the windings to break. Once a single inner-most layer of winding is broken, that's it; the pickup is "dead". Due to magnetic fields, the pickups may still work, but it will sound extremely thin and weak. Also, if you turn down the Tone control to that pickup, it will go complete dead and silient. That is a sure test of a dead Fender pickup. You can also measure the Ohms of the pickup. Dead pickups will register "open" (no resistance). But because the pots are in-circuit, an open pickup may read some bizarre high resistance, and the value may bounce up and down (again, due to the magnet properties of coils and the pots in the circuit). You should do the Ohm test right at the pickup leads, and to do it right, have one lead disconnected from the circuit (but please don't desolder any vintage guitar pickup leads!) Also the position of the pickup switch can effect values too, as can your fingers if they are touching the meter's probes. Just keep that in mind.
Another thing that kills old Fender pickups is someone trying to "adjust" the (non-adjustable) pole pieces (magnets). Because of the lack of a wound third (G) sting, some musicians push the G string magnet down through the flatwork, moving it further away from the strings. The problem is this can tear the inner windings. Since the magnets are in direct contact with the windings, and the magnets are sand casted and have rough sides, this will easily tear a winding. One torn winding will create a dead pickup (see the paragraph above).
Newer Fender pickups have been able to avoid both of these problems. Now, after the magnets are installed in the flatwork, lacquer is sprayed over the magnets and flatwork. Then the wire is wound around the magnets. This means the magnets are no longer in direct contact with the inner windings. Therefore, if the magnets are pushed thru the flatwork, they are less likely to tear the windings. Also there is less chance of a chemical reaction between the magnets and windings as they are insulated from each other by the lacquer. |
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Billy Gilbert
From:
Texas, USA
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Posted 3 Jan 2007 9:36 pm Dual Pro pickups
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Contact Rick Aellio here on the Forum about recharging the magnets on the sick pickup. He found that mine had two magnets of the same orientation instead of a North and a South. He turned one around and recharged both and now it really sings.  Billy |
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Rick Aiello
From:
Berryville, VA USA
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Posted 4 Jan 2007 5:41 am
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| Quote: |
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Since the windings of older Fender pickups are in direct contact with the magnets, this has caused some problems.with time, the magnets seem to chemically react with the windings/insulation, causing the windings to break. |
Respectfully ...
The coil is not in contact with the block magnets (not even close).
Thats the problem here ... the two magnets on either side of the coil are "yolked" (physically connected) to each other by the steel cover and base plates. The (N) poles of each magnet block are yolked ... as are the (S) poles ... promoting a more rapid demagnetization ... than if the blocks were not yolked.
Problem is ... this "yolking" is necessary and sets up the characteristic "around the strings" magnetic field ...
| Quote: |
Another thing that kills old Fender pickups is someone trying to "adjust" the (non-adjustable) pole pieces (magnets). Because of the lack of a wound third (G) sting, some musicians push the G string magnet down through the flatwork, moving it further away from the strings. The problem is this can tear the inner windings. Since the magnets are in direct contact with the windings, and the magnets are sand casted and have rough sides, this will easily tear a winding. One torn winding will create a dead pickup (see the paragraph above). |
Respectfully ...
There are no pole piece magnets at all ... the only magnets are the outer blocks.
What does happen ... is the coil is wound around a "cardboard" like material that tends to warp over the years ...
This "sags" down ... buzzing the strings. Pushing it back and propping it up with a non-metallic shim can be a fix ... but on real bad ones ... a new bobbin must be made.
| Quote: |
| Newer Fender pickups have been able to avoid both of these problems. Now, after the magnets are installed in the flatwork, lacquer is sprayed over the magnets and flatwork. Then the wire is wound around the magnets. This means the magnets are no longer in direct contact with the inner windings. |
Respectfully ... 
The Boxcar/Trap pickups found on Dual Pros and Customs are completely different "animals" ... than the conventional pickups found on Stringmasters, etc.
The "Pole Piece-less" design ...
The fact that the strings travel through both the coil and magnetic field ...
Pure genius ...
And in some folks opinions (mine, for one) ... the finest pup ever made ...
Well, until the "MRI" ... ... which borrows the coil design from the Boxcar/Trap pups ... and places it in a much more efficient magnet assembly ... 
Last edited by Rick Aiello on 4 Jan 2007 6:55 am; edited 1 time in total |
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Gary Lynch
From:
Creston, California, USA
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Posted 4 Jan 2007 6:53 am
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Rick,
That information must be about Fender guitars (not early steel guitars), and not the older pickups found on the Boxcar and trapsazoid pickups, right? In other words, is that information correct for Fender guitars?
So would the info be correct for the Stringmaster style pickup?
Information posted was from Seymour Duncan. |
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Rick Aiello
From:
Berryville, VA USA
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Posted 4 Jan 2007 7:04 am
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Maybe Roy Ayres will be by to answer that one ...
I know little to nuthin' about Fender "spanish" guitars 
The term "Direct Contact" ... that is sometimes used to describe these Boxcar/Traps ... is a strange term ...
The only thing I can see in terms of "Direct Contact" ... is the fact that the bridge on both Boxcars and Traps ... is actually the lip of the bottom yolk plate.
So the strings are in "Direct Contact" with the pickup unit itself ...  |
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Gary Lynch
From:
Creston, California, USA
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Posted 4 Jan 2007 7:17 am
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| Interesting. And thanks for easing my mind about the early Fender steel guitar pickups. |
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Dave Harmonson
From:
Seattle, Wa
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Posted 4 Jan 2007 11:35 am
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| Thanks for the response. I'll have to take a look and see if I can get this figured out. |
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