Pick-up info...

cerrem · Post by **cerrem** » Sat Apr 15, 2006 4:20 pm

I am curious about the pick-up evolution with the 4001... Like what was the last year for Horseshoe pick-up....and last year for toaster in the neck... i just assumed it was early seventies....like 1972....
Also I have seen pictures of two different treble pick-ups from the early 70's....
I have seen one that had black plastic as the bottom mounting plate.. it also has no holes on the top of bobbin, next to the outer poles..This measured in at 8K...
Now I have seen another that had a aluminum bottom mounting plate.. this one had two tiny holes on the top of the bobbin, right on the insides of the E and G poles...that pup measured in at 7.25K...
Can someone clarify some of this for me...

Thanks
Chris

jwr2 · Post by **jwr2** » Sat Apr 15, 2006 5:50 pm

last year for the horseshoe was 1968 ... the original horseshoe had magnetized steel shoes ... they were prone to demagnetize ... the neck toaster was replaced by the neck high gain in 1973 ... the neck pickup was moved back to a one inch spacing in 1975 ... the 4003 was introduced in 1980 and the modern 4003 came along in 1986 ... and the 4003 has hotter pickups than the 4001 ...

rickfan60 · Post by **rickfan60** » Sat Apr 15, 2006 6:08 pm

As Jeff said, '68 was the last year for the horseshoe but we have seen sporratic appearances of shoes on later basses into the early 70's. Perhaps there was an inventory of pickups that hung on a few years past '68 or maybe they were ordered that way.

The first high gains had screw pole pieces and aluminum base plates. Sometime in '73 (I think) the screws were replaced with poles that are very similar to screw nails. They have steep thread-like splines and broad curved heads. The later poles are adjustable if you are careful. The bobbin tops from the beginning to some time in the 90's were made of a layered fiber/resin material. I don't know what is called. Early ones were pale green in color but later ones were darker - almost black. The current pickups have molded plastic bobbin tops and poles that are very similar if not the same as the ones used in the mid 70's. Along the way the pickups got hotter. The current ones are much hotter than the 70's examples.

cerrem · Post by **cerrem** » Sat Apr 15, 2006 7:59 pm

After looking closer at the bobbin of the treble pick-up.. I see that it is the green sheet fiberglass board..
This is the same green fiberglass used to make circuit boards..it is most liklely G9 material...
Then it is spray painted with a sem-flat black enamel... pretty simple to make this bobbin...
I am trying to figure out what years they used the black plastic on the bottom of the treble pick-up as opposed to aluminum...
I will show some photos later..

Chris

rickfan60 · Post by **rickfan60** » Sat Apr 15, 2006 8:04 pm

The aluminum base plate disappeared with the screw-top bobbin. It changed to some kind of molded plastic when the slug top bobbin was introduced. So that is fiberglass on the older bobbins?

chefothefuture · Post by **chefothefuture** » Sat Apr 15, 2006 8:43 pm

There are no exact dates of change. 68 to 73 saw a great change in the treble PU: 68 was supposedly the last year
for horsies, the screw poles went sometime in mid 73.
The Aluminum base a little later. In 68 to 70 the bobbin was olive Phenolic. 70 to mid 71 saw a darker green Phenolic, 71 on they were painted black. The current PU uses a toaster bobbin which is molded plastic.
There are anomalies, most likely due to left over parts, or some one finding something at the bottom of the bin.

wints · Post by **wints** » Sun Apr 16, 2006 2:28 am

I still think it's highly unlikely that there is a bass that had a horseshoe coming from the factory after 68. With my stock Dec 68 4001 and a similar Nov 68 4000 I've seen, plus a couple of others here that had 69 basses new, all which had the hi-gain, makes me tend to believe that anything else is modified.

You can never say never tho'....

rickfan60 · Post by **rickfan60** » Sun Apr 16, 2006 3:47 am

You are probably right about stock production instruments but custom orders were common back then. Given that, it does not seem unthinkable that some were ordered with the older pickup type after the transition date. The same magnet assemblies were used on lap steels that were still in production so the materials would have been on hand.

wints · Post by **wints** » Sun Apr 16, 2006 5:37 am

Possibly Ted, possibly.

I still cannot recall a single bass from post 68, where an original owner can state it came with a factory horseshoe.

We'll keep looking...

rickfan60 · Post by **rickfan60** » Sun Apr 16, 2006 6:30 am

Someone posted pics a while back of a '71 with a horseshoe that appeared to be factory. There was at least one other. Yes, you are right that it would be difficult to prove they came from the factory that way.

jwr2 · Post by **jwr2** » Sun Apr 16, 2006 6:56 am

I saw a December 1968 4001 that the owner claimed that it came from the factory with a high gain ... I used to own a September 1968 4001 that came from the factory with a horseshoe ... so I would say the transition was late 1968 ...

cerrem · Post by **cerrem** » Sun Apr 16, 2006 2:42 pm

Hi..and thanks for the info...
I have two photos here of 4001 pick-ups... early 70's...
I am trying to learn more about these two treble pickups and I see difference between them and would like to know in what years these features were in..
The first photo here is a pick-up with a black colored plastic for the mounting plate..also notice the top of the bobbin has no tiny holes..
This pup measures in at 8.1K... It was claimed to be 1973???
http://img.villagephotos.com/p/2005-3/979985/ric-pup-a.jpg

The next pup is the one in my 1975 bass..
I don't know if it is correct or not, since one repair guy said it was replaced but did not offer to tell me any more details..but it has aluminum mounting plate and if you look carefully on the top of bobbin you will see two tiny holes on the inside of the outer poles..
This pup measures 7.25K..
http://img.villagephotos.com/p/2005-3/979985/ric-pup-b.jpg

Any info about these features and the years of these features would be greatly appreciated..

Chris

fran4001 · Post by **fran4001** » Sun Apr 16, 2006 2:52 pm

For what it's worth, here are the details on the treble pickup in my 100% original Jan. '69 4001 Burgundyglo, since departed. Olive green describes the bobbin color perfectly, unpainted. Base plate was aluminum, and was very crudely hand-cut. Pole pieces were screws. Measured 7.0 ohms at the time I sold.

walrus · Post by **walrus** » Sun Apr 16, 2006 2:52 pm

Here's a shot of the pickup on my Sept. 71 4001 for reference. Green with slot head screws and mounted on an aluminum plate.

cerrem · Post by **cerrem** » Sun Apr 16, 2006 3:03 pm

Wow...Bob, nice photo... I can see the little holes on the top bobbin..just inside the outer poles...
Fran...great info, about the aluminum base plate..you also confirm the 7K ohms....close to my 7.25K...
I am now puzzled about the black plastic replacing the aluminum bas plate or was it the other way around??

Chris