High Cost Domestic PAF vs Low Cost Import PAF

[antigua]

DiMarzio managed to trademark double cream exposed bobbins in the early 80's, and since nearly all aftermarket pickups have been produced by US based companies, DiMarzio has had a monopoly on the double cream racket.

Someone mentioned on another guitar forum that you can find double cream humbuckers from Chinese retail sites, and for dirt cheap. US trademark law doesn't extend to China obviously, so these are completely legal.

And here it is, the Donlis "Sell Free Shipping N&B 1 set Wax potted Cream color 4 output wires Alnico 2 guitar humbucker pickup"
www.aliexpress.com/item/Sel...259823681.html?spm=2114.13010608.0.118.J7Rlob

You're probably thinking, but yeah, they're crap pickups. But are they? I've taken the time to do a detailed comparison between the Donlis neck and the DiMarzio 36th Anniversary neck. I bought two Donlis neck pickups, only because I prefer low output bridge pickups, and I intend to use neck pickups in both positions.

The Donlis cream humbucker is also offered with AlNiCo 2 magnets, you just have to search AleExpress for it. There are quite a few interesting looking pickups, and I hope that be assuaging fears that these pickups are substandard, that guitarists might feel emboldened to mine their offerings. They would certainly be a more unique addition to your guitar than the pickup du jour from Seymour or DiMarzio.




Are the materials of good quality???


The only materials that are electrically relevant is the metal. The plastic parts can support neither a magnetic field, nor an electric current, so they are inert.

In order to compare the quality of metals, I've performed measurements for DiMarzio 36th Anniversary, then transferred the metal parts to the DiMarzio's coils, so that they bobbins and wire are constant, while the metal parts change.

Here is the Donlis beside the 36th Anniversary. The cover will come of for these test to make it an apples to apples comparison.





Lots of wax in the DiMarzio:




Baseplate Comparison 

First comes the base plate, and as you can see, the DiMarzio 36th Anniversary is not actually a PAF replica, as they allude to on their website, but a DiMarzio "airbucker", which just means they forego the wood spacer and retaining bar and instead place four plastic washers around two of the slugs and two of the screws. The effect is that there is about 15 to 20% less flux density at the pole and screw tops, which DiMarzio claims mimics the effects of a magnet that has degaussed naturally with age.



Here is the Donlis. As you can see, it uses the more correct spacer / retainer setup, but uses plastic instead of wood, as does Seymour Duncan, and even includes two plastic spacers. The reason there are two spacers is because, unlike the spec PAF, the conductor wire enters the baseplate on the same side as where the two coils hook into the conductor wire, where as original PAFs had the conductor wire entering on the opposite side of the base plate, so the conductor cable spanned all the way across that space along the top. The Epiphone ProBucker happens to be arranged the same way, except they used two wood spacers instead of plastic. 



And here is the test being performed, with the DiMarzio coils attached to the Donlis base plate:





Here is the measured result:



The black line is the DiMarzio baseplate. The Donlis shows a resonance about 200Hz greater, and peak difference is only 0.4dBV, which is to say the difference between them is completely inconsequential, and would be impossible to hear. 





Slug & Screw Comparison


In the picture below, the DiMarzio and its screws are far left, the Donlis is in the center, and a Gibson 57 Classic is on the right. The Donlis' fillister screw heads match the Gibson 57, where as the DiMarzio's screws have slightly smaller heads.



The way this test was performed was similar to the plate; first the DiMarzio was measured as-is, then the Donlis' screws and slugs were transferred into the Diarzio's coils, and then the measurement it taken again. For this test, there is no base plate under the coils, though I kept the AlNiCo 5 bar in place because, along with the wax, it was helping to hold things together.

4

The difference here is 60Hz and 0.4dBV, even less difference than was seen with the base plate swap, and that's really saying something, since these are core materials. Again, the differences are of no consequence, audible or otherwise.

</article>

[pablogilberto]

This is so interesting!

Based on the transfer characteristics, I think it's safe to assume that they will sound very much alike.

If we were to copy a specific pickup, given some parameters that we can alter, what do you think is the order of priority?
RLC values, Magnet type and strength, type of wire, wire gauge, wire coating, geometry (size and shape of bobbin), metal plates, screw and slugs etc.

[aquin43]

When you reassemble the pickups, do you get the same flux density readings at the poles as before? I would guess that you probably do because the magnetic circuit of the assembled pickup is so open that you will have changed the magnet's operating point by very little during the process if it is carried out carefully.

Arthur

[antigua]

Jun 21, 2020 23:41:10 GMT -5 pablogilberto said:

This is so interesting!

Based on the transfer characteristics, I think it's safe to assume that they will sound very much alike.

If we were to copy a specific pickup, given some parameters that we can alter, what do you think is the order of priority?
RLC values, Magnet type and strength, type of wire, wire gauge, wire coating, geometry (size and shape of bobbin), metal plates, screw and slugs etc.

The resonant curve and the magnetic strength are all that matter. The resonant curve defines the transfer function and factors in things like eddy currents, inductance and capacitance. The magnetic strength dictate string pull and any other effects that result from relation between the strings and the magnetized pole pieces. 

[antigua]

Jun 22, 2020 5:07:04 GMT -5 aquin43 said:

When you reassemble the pickups, do you get the same flux density readings at the poles as before? I would guess that you probably do because the magnetic circuit of the assembled pickup is so open that you will have changed the magnet's operating point by very little during the process if it is carried out carefully.

Arthur

I've never checked this specifically, but the magnetometer reading are sort of imprecise to begin with so I don't think it would be possible to observe something like a +/- 5% difference before and after. I have no reason to assume it would change as a result of reassembly. 

[aquin43]

Hi, what materials are the pickup covers made of?

Arthur

[antigua]

Jul 22, 2020 9:55:31 GMT -5 aquin43 said:

Hi, what materials are the pickup covers made of?

Arthur

The Donlis came without covers. They're generally always brass unless specified as nickel silver, and they did sell a nickel silver covered version, which I had another thread about. In this thread I was comparing it with a DiMarzio. This thread is relatively old, it would probably look a lot different if I made it now.