Differences between 4001s & 4003s

[soundmasterg]

If you cut the magnets, you'd want to recharge them again or you'd have some pretty weak pickups. The act of cutting them would be pretty hard to do well also, since alnico tends to chip easily, and its very hard also due to the cobalt. I'd suggest getting some new magnets with the correct dimensions and putting them in instead of cutting the current ones.

[rickfan60]

I left out a ton of detail and I probably got a year or two wrong but to the best of my knowledge, what I typed is the history of the 4001 in a nutshell. I did not mention the different control knobs and the dozens of variations in the shape of the pickguard. The subtle changes in the body shape (there were several of them!). There were also several different TRC styles!

[rickfan60]

It takes special tools to machine metal magnets. It is difficult and expensive to do it right. I suspect that is why Rickenbacker uses "plastic" magnets on some pickups.

[johnallg]

Well, it was a thought - thats about all that can be said for it now! Getting shorter magnets is a real possibility.

Has anyone, outside of RIC, ever quantified the magnetic strength of the different pickups? Doing it to an old 50s/60s pup now would not be indicative of the strength when made, though.

Which brings up the whole issue of vintage instruments/pickups and are we hearing them as they were when new....

[pflash4001]

Thanks for the comments. Yes, this bass will stay Mapleglo. Ric has some nice finishes, but I want to keep this one as original as possible. Like I said, it was my Father's. The neck pickup in that bass was sort of Frankensteined. It was like that when my Dad bought it in the early 70's. I don't have the original p/u. I got a pickup from Sergio here at the forum and it went in the neck position of my '79. I have the original pickup from the '79 in the case. I was thinking of having it installed in the '68, unless someone knows where I can get a more accurate pickup for this bass. Care to chime in on this,Sergio? I have said before, thanks for all the information and comments. You guys are great!

[pflash4001]

The TRC's on my basses are different. The '79 is white with raised lettering on it. The '68 is more like a clear piece of plastic with the lettering printed on the rear of the plastic and the white background over that.

[rickinroma]

There's nothing wrong with TRCs, Javier...old rickenbackers had plastic with letters printed on the rear

[bob_atherton]

Ted, thanks for that great post. You are a mine on RIC information.

[rickcrazy]

Hey Javier. How's everything going?
Yes, I remember sending you a couple pickups for your Ricks. One was complete with a toaster cover, the other... I can't recall what it was. The best bet for your '68 4001 is a toaster, naturally, even if any resemblance to a toaster pickup stops at the cover. Meaning your '68 could use a set of hotter pickups, and toasters are not that hot IMHO.

[rickfan60]

A correction to my first post: The high gain may have appeared first in 1968 as a replacement for the horseshoe pickup. I don't know for sure if the first under-string treble pickups were in fact called high gains but if they were, that is when they were first used.

[soundmasterg]

John, to check the magnetic strength of the pickups requires a gauss meter. My friend Dave Stephens from www.sdpickups.com has one and we've checked some of my RIC pickups to see what the magnet strenghts were. The toasters seemed to use alnico 5, and the ceramics in the hi-gains seemed to coorespond to alnico 5 as far as the strength was concerned. The Samarium Cobalt magnets in the humbuckers on my 230 were not as strong as I was suspecting before measuring them either. But this is an inexact science because you can degauss an A5 magnet to where you might think its an A2 for example. Unless you know the actual metallurgy of the magnet in question, it is hard to know what it is for sure.

[captain_jetglo]

I have a question, may be you can help me, there's a big difference between my two PU's in my '75 4001s. I have it capped and, the bridge PU sounds very very weak, I think I can make a good balance if I play in the central position, but if I play in the bridge position, there's a big difference with the neck PU. Is it right? the fact is that I like the sound of both working together. I have to say that I had it bypassed until last week, but the effect was the contrary, then the neck PU was the weak one and the bass and the strength of the bridge PU was awesome. Thank you for your help (in case you can understand all this gibberish)

[johnallg]

So you are saying the magnetic strength of a 4 pole high gain/ceramic and the 6 magnet toaster are the same, approximately?

[soundmasterg]

Sergio, that is normal. The cap cuts out much of the lows which is also where much of the power is. Take the cap out, and the bridge pickup can overpower the neck pickup. Best thing to do would be to change your playing style to accomodate the setup with the cap by selecting the middle position on the switch and back off the neck pickup volume until you have the tone the way you want it. That is what most people do who use the cap on the bridge pickup.

John, they are pretty close to each other on the gauss level...within 20%, which is about as close as you'll ever get with magnets. Its hard to tell sometimes just by checking the gauss what a magnet is or isn't. What really makes a difference is how the coil reacts and interfaces with the magnets, which can be measured by the inductance. You need a good meter like the Extech 380193 to measure this accurately, which I have. Things that affect the inductance level are the magnet type (alnico, ceramic, samarium cobalt, etc), the strength of the magnet (A5 fully charged, A5 partially degaussed, A2 fully charged, ceramic similar to A5, etc), any metals in or around the pickup such as a cover, or a keeper bar in Gibson's humbuckers for example, and the wire used, and also physically how these things are interacting.For example, having the magnets on the bottom of the pickup, or inside the coil changes the inductance. (how many turns of wire and type of wire used and tension all make a difference too)

The ceramic magnets don't load down the coil with eddy currents like an alnico magnet does, since they don't have any metal in them, so typically a ceramic magnet pickup is brighter, but this can be compensated for in the design of the pickup. I'd suggest that Rickenbacker did this purposefully when they designed the hi-gain, and the humbuckers too as they sound in the same ballpark as the toasters to where you can tell its a Rickenbacker. Having all the metal in the pickup covers plays a role and reduces output compared to if they weren't there.

The hi-gains are usually around 3.5 henries to 4.5 henries depending on the era from what I've seen. The toasters are from about 1.6 henries to 2 henries, though I haven't measured an 11k toaster, and I would guess it would be over 2 henries. The higher the henries number, the more output a pickup will have, and also the less highs the pickup will have. As a comparison a typical Strat pickup is 2.2 henries, a typical Tele bridge pickup is 3.5 henries, and a typical Gibson PAF is 4.5 henries. Higher gain humbuckers like a Seymour Duncan JB are more like 7 henries. P90's often have high henry numbers too.

[pflash4001]

Sergio! Como estas, hermano? Good to hear from you. Yeah, you sent me the toaster pickup, You said you were going to send a second one, but I never got another. Do you have something that may work better than the original pickup out of the '79 or would that one work?