I Think I Know How 4002 Pickup Positions Were Determined

[iiipopes]

I think I figured out how 4002 pickup positions were determined. Now that my band that I was in 25 years ago, Search & Seizure, is back doing an occasional gig here and there, I wanted a bass to play just for this band. The reason is that the lead singer now needs everything down 1/2 step (tuned down to D#G#C#F#) and I didn't want to expose any of my basses, especially my 4002 which I played as my main bass back then, to re-tunings, truss rod issues, or cutting nuts for larger diameter strings. So I bought a Squier maple J-bass VM body, a Squier P-bass VM neck (since I like the P-width, not the J-width) and put it together. Last year it did well for a couple of gigs. But I find myself with my left hand wanting the Rick 33 1/4 scale again, and uncomfortably stretching on the 34 Fender scale. So I resolved to purchase a fretless neck, no lines, no face dots, no side dots neck to have my local luthier fret it in Rick scale.

OK. Fine. But since the scale is shorter, how far to inset the neck into the body or otherwise modify to get everything to work? I first thought just rout the neck pocket the 3/4 inch difference. But that would put the neck pickup proportionally too far upstream, too mellow. Likewise, if I just mounted the neck and moved the bridge, the bridge pickup would be too close to the bridge to get any tone, and the neck pickup would be closer to the bridge and tonally start to take on characteristics of a Stingray pickup, which I did not want. Then it hit me: reverse engineer it. So I measured from the nut to the middle of the neck pickup on my 4002: 27 1/2 inches. Then I measured upstream to the nut from the middle of the J-bass neck pickup 27 1/2 inches and made a mark on the fingerboard. Then I measured the mark to the J-neck nut: 3/8 inches, half of the 3/4 inch difference between Rick scale and Fender scale! To confirm, I measured from the middle of the bridge pickup to the crown of the saddle on each instrument, and the distance center-to-center on the pickups. All also the same, if you move the J-bass bridge up the other 3/8 inch!

So I believe from comparing the measurements that in designing the 4002, Rickenbacker used the J-bass as the start, split the difference on the scale length, kept the pickups in the same relative positions otherwise, and carried on. So that is what I am going to do: have my local luthier rout an inset to the neck pocket by 3/8, move the bridge up by 3/8, and being a fretless neck, narrow it at the heel if it is still uncomfortable, say from Fender standard 2 1/2 inch heel width to 2 7/16 or 2 3/8, whatever is comfortable, shimming the sides of the neck pocket as necessary. The full thickness part of the underside of the neck heel is long enough to still have good neck screw points before the neck tapers.

Now, make no mistake: the bass does not now, and will not sound like a Rickenbacker after the mods. But my left hand will be relieved at modifying the bass to Rick 33 1/4 inch scale. And I wired it to rock with DiMarzio Model J pickups, .033 tone cap (like the original stack-knob bridge pickup circuit) and like the 4002, a .01 capacitor in-line from the bridge pickup to its volume pot. Pictures? It will take me awhile to get the neck. I'm not going to start the mods until my gigging season with this band is done for the year. So it will be a few months before pix. Please tell me what you think.

[cassius987]

Looking forward to the pics when it's done. I am curious how modifying the body goes for your luthier - if it's easy enough to do, I may try something like this some day. The other approach might have been to move the nut further into the fingerboard by 3/8'', but I think your way is better. Will you get more than 20 frets?

[iiipopes]

Looking forward to the pics when it's done. I am curious how modifying the body goes for your luthier - if it's easy enough to do, I may try something like this some day. The other approach might have been to move the nut further into the fingerboard by 3/8'', but I think your way is better. Will you get more than 20 frets?

Using the same conventional neck routing template, it should be no issue to simply clamp it 3/8 inch down the body and rout accordingly to get the extra inset. Since the neck heel is long enough, there should be no problem keeping the same neck mounting holes on the body. To use a "false nut" or repositioned nut would mean having to take more wood off the neck between the nut and the tuners to get a good down angle over the nut to properly seat the strings, which may cause instability in the headstock of the neck. 21 frets on a 33 1/4 inch scale is just a hair more than 1/16 inch longer than 20 frets on a 34 inch scale, and does not get into the rounded of portion of the neck heel contour, so the bass will have 21 frets with no fretboard extension. (the 20th fret on a 34 inch scale neck is about 23.291 inches from the inside edge of the nut; the 21st fret on a 33 1/4 inch scale neck is about 23.365 inches from the inside edge of the nut; the difference: .074 inches, which is actually narrower than the width of a vintage fret crown, which is about .078.)

[ilan]

I think they just eyeballed Fender J positions. A couple of millimeters in either direction don't make a real difference.

[iiipopes]

I think they just eyeballed Fender J positions. A couple of millimeters in either direction don't make a real difference.

Unfortunately, with all due respect, with 3/4 of an inch difference in the scale lengths, "eyeballing" it without measuring doesn't cut it, especially with fret and bridge placements. That is why I measured. Remember that Leo Fender's original gang saw to cut fret slots in necks was computed to the thousandth of an inch to assure accurate intonation. You can't "eyeball" tolerances that close. They must be measured. Otherwise, you end up with an instrument that will not intonate, has a sloppy neck/body joint, loose tuners, inconsistent tone from variances in pickup placement, and any one or all of a number of other maladies that must be sorted before the instrument is playable. Yes, a millimeter or two DOES make a difference.

[Isaac]

I think they just eyeballed Fender J positions. A couple of millimeters in either direction don't make a real difference.

Unfortunately, with all due respect, with 3/4 of an inch difference in the scale lengths, "eyeballing" it without measuring doesn't cut it, especially with fret and bridge placements. That is why I measured. Remember that Leo Fender's original gang saw to cut fret slots in necks was computed to the thousandth of an inch to assure accurate intonation. You can't "eyeball" tolerances that close. They must be measured. Otherwise, you end up with an instrument that will not intonate, has a sloppy neck/body joint, loose tuners, inconsistent tone from variances in pickup placement, and any one or all of a number of other maladies that must be sorted before the instrument is playable. Yes, a millimeter or two DOES make a difference.

For frets and bridge placement, sure. But for pickup placement? I'm thinking probably not.

[ilan]

For frets and bridge placement, sure. But for pickup placement? I'm thinking probably not.

Exactly.

Try a Gibson Grabber bass with the sliding pickup, it works everywhere, and for most of the travel even a half-inch doesn't make a noticeable difference.

Here's a simple experiment you can do: tune a Jazz Bass down a half-step and capo it at the 1st fret. You now have a Ric-scale Jazz bass. But it will sound the same, even if the pickups have now "moved" slightly towards the neck relative to the scale. It's way under the just-noticeable-difference threshold.

[iiipopes]

I think they just eyeballed Fender J positions. A couple of millimeters in either direction don't make a real difference.

Unfortunately, with all due respect, with 3/4 of an inch difference in the scale lengths, "eyeballing" it without measuring doesn't cut it, especially with fret and bridge placements. That is why I measured. Remember that Leo Fender's original gang saw to cut fret slots in necks was computed to the thousandth of an inch to assure accurate intonation. You can't "eyeball" tolerances that close. They must be measured. Otherwise, you end up with an instrument that will not intonate, has a sloppy neck/body joint, loose tuners, inconsistent tone from variances in pickup placement, and any one or all of a number of other maladies that must be sorted before the instrument is playable. Yes, a millimeter or two DOES make a difference.

For frets and bridge placement, sure. But for pickup placement? I'm thinking probably not.

The whole point of this thread is scale length and pickup placement. As Cassius987 will confirm when he was considering pickup placements on a bass he was rebuilding, we did experiments with a suspended pickup to analyze the different tones of the same bass and set of strings comparing and noting the tonal changes from different placements of the same pickup. If you search the forum, you will find numerous threads on the tonal differences of the 4001/4003 basses on the differences between the "one-half inch spacing" compared to the "one inch spacing" of the neck pickup. Likewise, these consideration apply to every other pickup placement on every bass ever made, whatever the make or model. I wanted a bass that would have the same scale, same pickup placement, and therefore a similar, if not necessarily a Rick-ish tone otherwise, and similar ergonomics as to both fretting hand and plucking hand, to my 4002. In short, yes, it does make a difference. To expand on the above post and this post, EVERYTHING makes a difference: scale, pickup placement, body wood, neck wood, bolted vs. neck through, fretboard wood, etc. The real question is whether it makes a noticeable difference. Including playing bass, as well as piano, guitar, and school concert band brass instruments, including everything from trumpet and tuba, and over fifty years of classical chorus experience, from Sunday School "Jesus Loves Me" to college scholarships, and private study in acoustics, including the pioneering treatise by Hemholz, "On the Sensations of Tone," to learn the finer points about what constitutes a tone, what constitutes overtones, and everything that can change and alter the perception of such, and the study of acoustic theory, including how the ear perceives overtones, yes, it does make a difference. I recommend you read this essay on fundamentals and harmonics as a beginning reference as to why it is important: http://barthopkin.com/fundamental-harmo ... als-modes/

[iiipopes]

For frets and bridge placement, sure. But for pickup placement? I'm thinking probably not.

Exactly.
Try a Gibson Grabber bass with the sliding pickup, it works everywhere, and for most of the travel even a half-inch doesn't make a noticeable difference.

Here's a simple experiment you can do: tune a Jazz Bass down a half-step and capo it at the 1st fret. You now have a Ric-scale Jazz bass. But it will sound the same, even if the pickups have now "moved" slightly towards the neck relative to the scale. It's way under the just-noticeable-difference threshold.

No, you don't. You have a 32 inch bass scaled down, not a 33 1/4 inch bass scaled at concert pitch. It does not sound the same. I have played Grabber basses, when they were new all those decades ago. My friends and I all perceived noticeable differences tonally with fresh round wound strings. And by the way, the range of travel of the pickup is about two inches. For you, it may not be noticeable. But for me, with my 50+ years of studying tone, it does make a difference, as well as the ergonomic differences in scale length and the placement and approach of both the fretting hand and the plucking hand. Moreover, you must read about Ralph Novak and his research into the different tonal overtone structures produced by different scale lengths. I am sorry you cannot perceive the differences.

[Isaac]

People don't seem to be paying attention to what Ilan actually wrote. He said, "A millimeter or two," not a half an inch, which is over 12 millimeters.

Yes, everything makes a difference. No, the difference is not always audible. In the absence of proof to the contrary, I agree with Ilan, that a millimeter or two in pickup placement is not going to make an audible difference. And even when a difference is audible, it isn't necessarily better or worse, just different.

[cassius987]

As Cassius987 will confirm when he was considering pickup placements on a bass he was rebuilding, we did experiments with a suspended pickup to analyze the different tones of the same bass and set of strings comparing and noting the tonal changes from different placements of the same pickup.

That was a fun and ear-opening experiment that led me to put a P Bass-spaced Toaster pickup in my modded 4001FL. I have definitely found pickup placement to be one of the most meaningful factors in tone, alongside pickup construction and overall bass timbre (which is imparted by a combination of many things). Body wood (as a factor acting alone) falls beneath all of those, the 4003W series being a good example.

Whether 1 mm makes an audible difference I can't say, but considering Scott's measurements, I do find it hard to believe the positions were eyeballed.

[Malchik]

Should have seen in Warmoth could have set you up with something.

[iiipopes]

Should have seen in Warmoth could have set you up with something.

In years past, I have contacted Warmoth on other occasions, for example a neck for my fanned fret bass. It either would have cost more than a Fender Custom Shop bass, or they flat said they did not want to do it. As far as that bass is concerned, Sheldon Dingwall fretted a blank neck I got from the former supplier to Gibson all those years ago. Now, I have a local luthier who is highly skilled, reveres Rickenbacker instruments (picture of the bass as refretted after I wore the frets out after decades of gigging), takes care of many of the instruments used in the shows in Branson, MO, which is just south of where I live, and understands what my projects are all about, and is reasonable with me.

[admin]

This has been a most interesting thread and underscores the passion and preoccupation that musicians have with regard to instruments' pickups, placement and tone. I, like so many, began my tone quest early as a teen with regard to swapping out pickups on various guitars. While lacking the formal training in physics and instrument design my experimentation confirmed to me that different pickups at different positions on an instrument had a significant role to play with regard to tone. I appreciate the interest shown here in concert with the spirited discussion and the understanding with regard to the different points of view expressed.

[rickbass]

Wow....one of the best discussions I have read in a long time. I love the idea of tuning down and then capoing !! I would have never thought of that. But that actually will move the pickups closer to the neck, for an overall warmer sound I would think. Perhaps that idea is what some people might be looking for soundwise.