Wanna see the guts of a Rickenbacker 4001 bass pickup? [Pictures] - created 10-26-2008

Searcy, Clint - 10/26/2008.20:27:16
MIMForum Staff, Nashville

I thought you guys might like to see the odd little duck that is the Rickenbacker 4001 neck pickup. Lemmy, Chris Squire, Rick James, Sir Paul, Geddy Lee. The Ric sound it distinct and this strange little pickup is a big reason why.

Big magnet stuck on the back. I think it's ceramic.The keeper is aluminum.

The poles are steel rivets and the flat work seems to be phenolic that's been painted black.

These used 44 ga wire. Look at how sloppy the whole thing is put together. The magnet is off to one side. This one was sent to me for a rewind because it was dead but the real problem is that the cold solder joint at the grounding ring broke.

The good news is it won't need a rewind.

Clint- What year is it? Construction looks like deArmond.

I don't know yet. I waiting for the owner to call me back. I think I'll go install it in my test bass and see if I can still play Star Ship Trooper! I know I still have Ace of Spades down cold.

Lemmy says, "Just say no to yes."

I don't think Clint will mind if I add some pictures?

Here's a bridge pickup from a 1973, 4001. The pickup Clint has there is mid to late 70's, as they had switched from using a guitar toaster neck pickup, to the pickup clint showed, which is pretty much made the same as the bridge pickup. After that they made a few changes to the model of the bass, and renamed it the 4003. They continue to use that pickup. So his is from a 4001, so that sets the time frame.

Interestingly the toaster has nice mounded plastic bobbins. So there must have been some reason for them to fabricate the bridge and later neck pickups from phenolic PCB material. But I guess that's how they did it, and that's how they still do it. It's all very home made looking, but not in a bad way, more of a quant old school way. They do look like old DeArmonds, since they are of the same era. Old Carvin pickups as well. I had heard that Carvin made the early Ric pickups for them.

My bridge pickup needed to be rewound. So here are some photos as I took it apart, and removed the old magnet wire. I haven't rewound it yet.

There were a few surprises awaiting inside the pickup!

So here's what the pickup looks like. For those unfamiliar with this bass, this pickup replaced the original "horseshoe" pickup, which had two steel horseshoes around the strings. Originally they were cobalt steel magnets. So this was the coil part of that pickup without the shoes. They replaced the shoes with a chromed cover.

As you see, exact same construction as the pickup Clint showed, but mounted on a big hunk of aluminum!

Bottom view:

The older pickups used screws instead of rivets.

Here I removed the aluminum mounting bracket from the pickup by loosening the two machine screws.

Under the bobbin is a large rubberized ceramic magnet. They cut a notch in it to accommodate one of the hookup wires.

You can see the magnet wire under the black electrical tape. The pickup coil was coated in lacquer or varnish.

Here I have removed the 44 AWG magnet wire. Now for surprise number one! The white hookup wire that enters the bottom of the pickup is terminated on this screw in the middle of the coil!

The screw poles are taped off with electrical tape, except it goes behind the screw. The screw has a file mark in it to rough it up, and a solder joint was made on that spot.

An angled view:

Now for surprise number two. I could see something behind the black tape that covers the screw poles. So I removed the tape and... foam rubber! It's some kind of foam rubber tape.

Probably as protection for the magnet wire?

The bare, naked pickup. Not much to it!

Eventually I will be restoring the bass it came from. Here it is in its present state. Too many years of modifications! I plan on posting that here when it happens.

Great thread Clint! Too bad you didn't get to see inside the pickup. I wonder how similar it is to this one.

Cool to see those old pickups naked. Do you guys have any of the Rickenbacker Lap steel pickups torn apart? I think some of the old bass pickups were similar design, weren't they?

Ellie, I think the lap steels used the horseshoe pickups, which was their standard pickup for a long time. They even used them on the electric violins and upright basses they made.

They started out by putting the horseshoe pickup, which was invented by George Beauchamp, into Harmony made acoustic guitars. I've seen a few of those old ElectroString guitars.

I too have always liked and wondered about the Ric bass sound, and I appreciate getting to see how these pickups were made.

David,

Is a "rubberized ceramic magnet" a ceramic magnet coated with rubber, or something more like a refridgerator magnet that's flexible? Is this to isolate the pickup from the rest of the body?

What purpose do you suppose the foam rubber core serves? Bigger air gap?

It's a rubber magnet, like used for refrigerator magnets. John Hall has said they used it because it got the tone they were after. I'd take that with a grain of salt, and it might just be that it was easy to work with. I think it's too hard to serve as a vibration insulator. Who knows?

I think the foam rubber was to protect the windings from the sharp threads on the pole piece screws. I've been told that they no longer use the foam rubber in the pickups.

I haven't decided if I'm going to put some back in, but probably not.

Thanks for adding info to this David. I was hoping you might chime in because I know you have messed with the Ric pickups a lot. I finally got a note back from the owner who says this one came from a 1971 4001. But... he is a regular client and his information is not always reliable. This magnet isn't the rubberized kind and the winding has a DC resistance of about 8.55K ohm.

Wikipedia says: "4001 models continued to use the Toaster for a neck pickup until around July 1973" so it must have right after my two basses were made, though one of my basses was made in August '73, and the other is in March.