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62 Gibson EB0 - 1 humbucker + 1 (dead) JB pickup. What to do?

Discussion in 'Pickups & Electronics [BG]' started by Jim Baritone, Jun 19, 2012.

  1. Hello everyone, and thank you for the warm welcome I've received here at TalkBass.

    I'm starting this new thread as an outgrowth of a thread I've been part of in Luthier's Corner, http://www.talkbass.com/forum/f57/m...ighter-pickup-871779/index2.html#post12752050

    I have a 62 Gibson EB0, received in lieu of wages in 1975. At the time, it had been modified by the addition of a Fender JB neck pickup halfway between the Humbucker neck pickup and the bridge. The wiring was an atrocious nightmare, and the bass beaten up - but it played. At that time I played full-time pro, sax but also bass. About 1980 I made a semi-successful attempt to clean up the earlier owner's re-finishing job. Sometime later, the JB pickup quit - went open-circuit - and so I bypassed it and went back to the original 1 humbucker config. To my shame (since I later became an electrical engineer) I didn't rip out the whole control circuit at that time.

    I'm now retired (early on disability, unfortunately), and have time to do something about this. I've always liked the bass, so fixing it up seemed like the right thing to do. Restoring the finish is a separate issue; the reason I'm posting here is for advice about pickups, and replacing/rewiring the dead one.

    The original kludge install had a 2-position "either/or" switch - neck or bridge - feeding into a single volume and tone pair, then the jack.

    Since the rout is already there for a JB pickup, my first thought was to install another JB pickup or aftermarket with similar dimensions. Wiring up the 30 K humbucker to a 7.5 K JB single is a whole other question. 3-way switch, with middle as "blend" has been suggested, as has series/parallel. I've also had it suggested that I just use 2 volume controls and forget the tone pots.

    Pictures of the body and the rout are below. The existing control cavity has two pots and the 2-way switch.
    I'll post more pics as opportunity presents itself.

    Any advice as to what to do, what pickups to use, how to wire them and/or what controls to install, would be greatly appreciated. I've had pickups suggested from stock Fender JB replacements all the way up to Rio Grande's and Darkstars. My budget is limited, so any large-cost changes will be incremental.

    Many thanks
    Jim Baritone


    El Pelusa likes this.
  2. And just for information's sake, here is the present wiring inside the EB0, along with a photo of the cavity. I plead guilty that I didn't just strip out the whole mess and start fresh, but at the time (1975) it wasn't feasible. There's a copy of the original Gibson EB0 schematic located here


    for comparison.

    As you can see in the second photo, the original factory finish on the mahogany was Cherry Red. It's now neither "Cherry" nor "Red" More like Redwood.....

    Jim Baritone

    Attached Files:

    gip111 likes this.
  3. GlennW


    Sep 6, 2006
    If it was mine the main goal would be to hide the J route. Like by:

    1) filling in the route and covering it with a sticker (no refinishing to deal with), or

    2) making a rectangular surround big enough to cover the J route and finding another bridges pickup (maybe even a dead one, just to get rid of the slanted J thing).

    The easy thing would be #1, and since there's a hole for a switch, maybe use it as a cap selector.
  4. Well, that's certainly an option. Some pictures were posted here:


    of various dual-pickup EB0 conversions.

    However, another member, Beej,made an interesting point in the following post:


    "This may sound a little crazy, but if this were in my hands, I think I'd keep it as it is. Well, actually, I'd either have the "original" added Fender Jazz pickup rewired to work again, or I'd try to find another period correct Jazz pickup, early 60's if possible.

    The reason being is, this is not some modern destruction of a precious Gibson EB0, this is a very early example of a custom modified bass guitar in order to produce a sound not available at the time. To me, this is like finding a rare early Mustang with a custom supercharger installed shortly after purchase - it still has provenance and collector kitsch value as it is and might not necessarily increase in value by attempting to restore it to original.

    Especially in this case since pretty much any possible restoration will likely show at least a little, and it would be high dollars to get a near perfect repair."

    And of course, as another member pointed out, there's the Mike Watt option, as shown here:


    There are pros and cons either way. One thing that's swaying me toward adding a new 2nd pickup is that when I got the thing, the original Fender JB didn't sound too bad at all, even by itself. It certainly had a different quality to the growler up at the neck.

    Jim B
  5. pharaohamps

    pharaohamps Commercial User

    May 30, 2006
    Garner, NC
    Owner, Disaster Area Designs / Alexander Pedals
    +1 on this. Anything you do short of a complete refinish is probably going to look like more of a hack-job than what's on there already. The nice thing about the current control setup is that the switch offers you a little more control than what you might get if you had a Jazz-style V-V-T setup. You can use an DPDT center-on switch to select neck, both, bridge, and you can sum the two pickups through a couple of resistors to balance them if they turn out to be wildly mismatched.
  6. GlennW


    Sep 6, 2006
    If you like how it sounded with the J pickup that's even easier, less work for you to do. There are plenty of replacements that'll fit. You might want to confirm what size J pickup you'll need before you start looking. It's possible that it was routed to accomodate a neck pickup (which is slightly smaller than a bridge pickup). You might find an SX ot Squier J pickup real cheap on ebay, and they sound pretty good.
  7. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    Electrically speaking, the trouble with this setup is the fact the mudbucker is an extremely-high-Z pickup - we're talking about the 32 kOhm ballpark here. Any other pickup you take will likely be close to 8, maybe 9 kOhm which will boil down to a lot of tone suck, as that's what happens when two mismatched pickups are joined together.

    My first suggestion would be to try and wire the mudbucker in parallel. Since the two coils are equal, in series they have twice the impedance of one (that's the total 32 kOhm mentioned above). In parallel, they have half the impedance of one, which is 8 kOhm, which is much more manageable and blends much better with other pickups. So, maybe you should try the mudbucker in parallel and see how that works for you.

    Alternatively, someone could probably think up a wiring that replaces your selector switch with a rotary that gives you:
    • mudbucker in series with itself
    • mudbucker in parallel with itself, in parallel with the singlecoil
    • singlecoil solo
    That'd let you keep the woofy tone in the neck-only position and something more blendable in the mid position.
  8. As you say, it could wind up as a worse looking hack job, which I'd like to avoid, all things being equal. I know the EB0 is not a renowned bass for tone quality and flexibility, but I've gotten kind of attached to it, warts and all. It's served me well, and although some sonofagun stole the original hard case from a gig, it's remained undamaged (any more than it was when I got it, LOL).

    A 3-position switch - stock Gibson 3-position, with neck, both, bridge - would not be out of place. If need be, I could probably fit in a series-parallel switch and make it fairly inconspicuous, or better yet flush-mount a slide switch on the control cavity cover, backside.

    The impedance mismatch with the Humbucker and the JB in parallel is a problem, no doubt about it. The humbucker meters out at about 30 kOhms DC, and about 160 Henries as an inductor. The JB pickup (and it is definitely a '60's JB neck pickup - the mounting holes are exactly 1.49 inches apart - see DiMarzio's page on dimensions) is about 7.5 kOhms DC, and only about 8 Henries as an inductor. Wildly different characteristics for both DC and AC or "signal" voltages.

    I've kicked around a few ideas, including replacing the original Gibson neck pickup with a 4-wire DiMarzio humbucker, which would allow switching the two coils in the neck pickup to reduce the resistance/impedance, and make it more evenly balanced with the JB-type pickup.

    Another idea I had was to run each pickup into a FET buffer - each pickup would see its own high impedance (and that could be tailored for each pickup), and the output of each could be adjusted to give more-or-less even levels from each one. From there to the 3-way switch, and to the volume/tone pots.

    I could probably build something, but I'll bet if I look on EB there's already something along those lines available - probably cheaper than what it would cost me to buy the parts.

    I see DiMarzio make a Humbucker Jazz Bass pickup set, so if I used those at least I'd be going like with like.

    Just some random thoughts I've had while looking at reviews of pickups today.

    Jim B.
  9. Glenn,
    Yes, it is definitely a neck pickup. I measured the cover mounting holes, and they are 1.49 inches on centers, exactly like a 60's JB neck pickup. There seem to be quite a few drop-in replacements for the JB pickups, so it's really a matter of a) sound & quality, b) cost, c) availability.

    I've debated rewinding the neck pickup I have (I did attempt a repair, but I found four broken wires in the first 2000 turns as I was pulling off the old wire, so I gave that up for the time being. I've no local source of 42 gauge magnet wire, and the cost to import it is really shocking - I could buy a pretty high end pickup for what it would cost to import the wire, and then I'd still have the job of rewinding it, And, after all of that, it would still be a 9000-turn neck pickup, pretty much the same as the stock ones

    I looked on EB, found JB pickups as low as $9 and as high as $165, so there's definitely a range of options..

    Jim B
  10. You've hit the nail square on the head as far as the impedance mismatches and "tone sucking" I think this is why the original owner (or whoever did the mod prior to 1975) used an "either/or" DPDT switch, rather than a 3-position switch with a "Blend" hookup in the center position. He may have tried it and found, as you say, that the mismatch was just too "tone-sucking" to be worth trying to get working.

    The guy who did the rout did a good job, and he even angled it so that the JB pickup poles lined up with the narrower Gibson strings (another poster pointed this out to me - it was a real *doh* moment). The "electrician"s work is not of the same quality as the woodworker. There must have been about a quarter pound of solder blobs rolling around loose in the control cavity when I took the cover off.

    I am a little reluctant to start cutting my existing original mudbucker, but if I could find a replacement from an Epiphone, or an aftermarket humbucker, I could play around with various coil combinations. A rotary switch is one option - another is a bank of four or five SPDT "on-off-on" minis, wired to allow selecting all the coils in series, parallel, or some combinations. I found a whole web site on making coil switching networks using toggle switches, and I'm darned if I can find it again

    I have a feeling that I'll be fitting connectors onto my pickup wires, and then sticking a switch breadboard to the body with double-faced tape, just to get the coils and capacitor combos sorted out.

    As I mentioned earlier, there's also the option of making a FET buffer, either with zero gain or low gain, and matching the pickup outputs that way. I'm a bit reluctant to put in any kind of active device, but I know people have done it, and successfully.
  11. Although this is not strictly germain to my electrical problem, the EB bass in this pic is what I'm aiming for in general terms of quality of finish and "customization" It's not an original factory color - not even close - but beautifully done. The two DarkStar pickups I'll probably have to pass on, unless I win the lottery. However, the pickguard made up of laminated exotic wood veneer is really eye-catching, and adds a lot of class to the finished look.

    I have a friend who knows a wee bit about cabinetmaking and exotic woods, so I may just hit him up for some help on that one.

    I really like the look of this EB. What's also kiid of interesting is that the finish color is not that far off from the current finish color on my EB0. What's different is that the one in the picture was wet-sanded with finer and finer finishing paper between coats, and then the clear coat was buffed on a cloth wheel, using a very "un-cutting" polishing compound. Or at least that's what I've been told by people who know more than I do about wood finishing....

    Jim Bari

    Attached Files:

  12. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    In that case, a cheap mudbucker like an Artec EBC4-CR should do nicely. They don't advertise it on their site, but if you e-mail Artec they should have a couple in stock. Otherwise, you might want to email the people at GuitarFetishStore or check the BassPartsResource site for their models. The price for all of those is rather low (close to 30, maybe 35 bucks) and they have a really smooth sound, very close to the original mudbucker.

    The thing with replacement mudbuckers is, occasionally they don't act humbucking as they're supposed to. The last couple of cases on TB were caused by the fact the factory accidentally switched the leads of one of the coils, or one of the magnets was flipped. You can read all about it in this thread

    Maybe it was this one?. Either was, a network of toggle switches under the hood would be better if you just want to fiddle around and don't mind playing with an open electronics cavity while you're testing.

    Also a valid option, goes with what I said above.

    It's also an option. If you want to go down that route, you should try either making a Tillman preamp, the Alembic Stratoblaster preamp or the Fender Elite preamp. All simple buffer circuits with some slight tone shaping.
  13. Stealth,
    Thank you for the time and trouble that went into your reply. You've obviously been around the block a few times on this type of thing. My EE experience was in RF, computer logic controls, and feedback loop control circuits. Also very high voltage plasma jets, but that's almost physics as much as engineering. Also did some interesting work on building diagnostic instrumentation to measure explosions and shock waves, and a bit of ultra-high-speed videography as part of that. Interesting stuff, but noisy.

    Haven't done much (professionally) with working on audio frequecy circuits. I'm not familiar with the Tillman preamp, the Alembic Stratoblaster preamp or the Fender Elite preamp, but now that you've mentioned them I'll do some research on all three.

    One nice thing - I may be retired on disability, but I can still use a soldering iron pretty well, except for really tight SMT stuff (I either turf & replace that stuff, or take it to a pro who has all the right equipment).

    Interesting that you should mention ARTEC EBC4-CR humbuckers.

    I was just looking at their "humbucker" JB Neck pickup on EB Model JOA4N-1 - I have not looked at their Gibson mudbucker replacements.


    Another thought came to me as I was paging through the EB stuff - I noticed that Artec have a small 2-band preamp, their model BE-2. It has four pots mounted to a circuit board, with a cutout for a battery in the middle.


    Description here:

    The controls are Bass, Treble, Balance and Volume.
    So, thinks I: What if a person was to remove the four pots from the board, and run shielded wires from each pot board connection to one of two new concentric dual pots (4 pots in total). This would act as an equalizing front end for the two very different passive pickups, and would (using concentric dual pots) not require drilling any more holes in the body. A logical combination might be Bass/Treble on one concentric pair, with Blend/Volume as the other.

    I don't know what values the pots mounted on the Artec BE-2 board are, and the values are not specified in the layout drawings. Perhaps someone knows - I'm still reading the threads on various Artec preamps. They seem to have an overall favorable rep as a low-end "starter" option.

    Now, does this sound like a possibly feasible idea, or have I just slipped my clutches altogether? :help:

    I haven't gotten as far as thinking about how a person might incorporate series/parallel switching, or phase switching, or humbucker coil selection combinations.

    As to the multi-switch pages, they were indeed at the 1728 site. I don't know that I'd want to build such a thing into this bass, but it would be a useful way of testing out all of the various combinations.

    Just a few idle thoughts this rainy afternoon...:meh:

    Thanks for your good suggestions.

    Jim B

    nd a postscript I've just tripped across: someone has done this combo before, except that they installed a Gibson mudbucker as well as the Artec EBC4-CR mudbucker clone into a JB body with a no-name JB pickup as the "other" pickup.

    Links here:



    To quote the author, "When both the Mudbucker and the Jazz bridge PU is parallel connected, the difference in impedance causes the Mudbucker to loose volume and bass, and it sounds no fun all!
    The unbalanced PU:s had to be dealt with, so I mounted a small switch beneath the tone knob.
    Its purpose is to cut bass from the bridge PU (Rickenbacker style), so that the Mudbucker doesnt loose bass when both PU are at full volume. Sound strange?
    The schematics"


    "A: The bridge PU has normal function,
    B: Cap nr 1 is connected in serial, and cuts some bass
    C: Cap 1 & 2 is connected, more bass reduction."

    Interesting approach to what is basically the same problem..... he has some mp3 sound clips posted also
  14. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    I've dug out some links from my bookmarks for you.
    The ideas aren't bad, save for two things - one, you have to provide individual channels for each pickup before blending them in order to avoid tone suckage. The Artec preamp doesn't have an active blending stage, so it will mix them passively and defeat its own purpose. It should be a good enough preamp after the mixing, though. The second problem is, blend/volume pots are hard to come by and expensive to boot.

    Found that page two days ago as well, maybe that would be the simplest, and thus ideal solution.
  15. Hi Stealth,
    Many thanks for the links. I read through the Tillman preamp and had a bit of deja vu. It's practically identical to a little FET front-end we used to use on instrumentation back when I worked in research - I think we got the basic circuit out of one of the component "cookbooks" that suppliers used to send us. I remember making up a batch about 25 of the little suckers and putting them in little metal boxes with BNC connectors on each end to plug into the 'scopes. I doubt I still have the PCB layout - the software I used to generate the board ran on pre-Windows computers - but it's so simple that I'd just run them up on perfboard.

    I didn't dissect the others in detail, as I think the Tillman circuit will do the job just fine. If I'm wrong, then I can try a different one as "Mk. II".

    I gave the Artec preamp some more thought last night, and even went through and sketched out the circuit (as much as possible, anyhow) from the board layout. You're absolutely right - it would be no good without putting something in each pickup line before the preamp. I think maybe a couple of Tillman FET buffers are a better option.

    The Scandinavian chap's project is interesting, and his fix is probably the first mod I'll try, once I get a new JB pickup put in. I'm ordering an Artec JB pickup as a stopgap, and then will decide on which way to go for a higher-end one - DiMarzio, Duncan, or whatever.

    I may have a line on an EB3 humbucker - a pull from an upgrade project, now apparently sitting in a drawer. If I get that I may try the Hills Cloud coil-splitting mod.


    As I mentioned, I'm reluctant to do surgery on my existing pickup, since it's the only working pickup I've got left, and 50-year-old wire can be pretty brittle.

    One idea that kind of interests me, besides the possibility of doing a coil-tap/coil switch, and of series/parallel switching of the two pickups, is having a selection of tone caps. Maybe only for "research" purposes, and then pick the best ones and close it up .

    A multi-switch layout has the downside of being fugly to put in. There's not very much room in an EB0 control cavity to begin with, and although caps don't take up much room, switches do.

    I'll probably try the "flower power" mod first, once I get a second pickup, and then experiment from there.

    Ric5 put up an interesting picture of a mod done to an EB0 - moving the jack to the edge of the body, thus freeing up some room in the cavity, and using a JB control setup - 2 vol & one tone.



    Other work in the pipeline is making shield liners for all of the cavities, and possibly changing out the bridge.
    The shield in this picture looks like a "factory made" one, so perhaps there are aftermarket ones and I can save myself some work.


    As to the bridge, the only real problem with that is that I haven't enough experience to pick a replacement bridge. I've played the EB0 with its stock bridge and, since I'm not a full-time bass player, I haven't had much chance to compare it with others (except the "purple smartie" stereo Rickenbacker of many years ago. wish I still had it).

    Thank you again for your suggestions. I really appreciate the help! For as long as I've been playing music, and fooling around with electronics generally, I'm still a complete newbie when it comes to guitar pickups, controls and wiring.

    Many thanks,
    Jim B
  16. Well, I found and ordered an ARTEC EBC4-CR humbucker, so now I can coil-cut and modify that and not feel guilty about farbling up my original Gibson neck pickup. I also ordered the Artec JB neck pickup - strictly as a stopgap.

    I guess the next project is to figure out what combination of wiring and/or switching circuits will give decent results.

    Right now, some of the options are:

    - Neck and bridge pickup in parallel (bad idea, tone sucking)

    - Neck and bridge pickups, each with its own Tillman FET buffer, in parallel, 3-way switch Neck/Both/Bridge.

    - making up a set of control pots. In Gibson style, I'm thinking to put each pickup's control pot ahead of the 3-way switch. I'd probably use a set of concentric pots, 1 pair of 500K audio taper for volume neck and bridge, and 1 pair of 500K linear taper pots for tone. Lower rings would be bridge, top knobs would be neck.

    A second possibility would be JB type wiring - 1 volume for each pickup and a master tone pot. 500K pots all 'round, audio taper for volume and linear for tone.

    There are also some other possibilities that have cropped up in my reading through the archive threads:

    - Making neck and bridge switchable between series and parallel hookup. (just exactly how, if at all, this could be included in the conventional Gibson-style wiring I don't know.

    - doing a coil-cut on the Artec neck humbucker, then wiring up the two coils for series, parallel, in phase, out of phase, etc.
    This could be an entire project all by ltself.

    - Putting in a series of switchable tone caps, maybe on a rotary switch.

    The more I think about this, the more nuts it drives me.
  17. SGD Lutherie

    SGD Lutherie Banned Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    One thing to keep in mind; some of these Artec pickups are wired up or assembled incorrectly, and they hum when they shouldn't. The two errors I have seen are the magnets not being installed correctly, or one of the coils wired up in reverse, or installed flipped around the wrong way.

    It's easy to fix, so if you pickup is humming, that's why.
  18. Stealth


    Feb 5, 2008
    Zagreb, Croatia
    Jim, if that were my bass and I were going for an active, more modern tone, I'd go with the:
    • series-single-parallel switch on the mudbucker
    • Tillmans for each pickup
    • active (low-resistance, 10k or 25k) blend and a stacked volume/tone (also low-resistance)

    Were I going for a more passive tone, I'd go with:
    • series-single-parallel switch on the mudbucker
    • vol/tone passive (250k lin/250k log) stack for each tone, caps to taste
    • passive tone simulation
    • Tillmans for each pickup
    • three-way pickup selector

    The passive tone simulation is a resistor in series, and a capacitor in parallel, with the Tillman input to simulate the effect of cable length and capacitance, but I don't know the exact values.

    Yeah, David, your help in the other thread shone a pretty bright light on how to solve that problem. I linked to it in one of the earlier posts. :D Would you know the ballpark values for cable capacitance simulation?
  19. Either of those sounds like an excellent route. I suppose that, just for the sake of starting on familiar territory, I'll go with the passive pickup route to start off with. I can put together a couple of Tillmans on a pretty small board, even if I don't use surface mount (which I'm not equipped for anyway).

    The stacked pots are no problem, either availability or space (I think) and I should be able to make the 3-way selector look pretty much as if its supposed to be there. I know it'll never look absolutely "stock", but I'd like the finished layout to not look too out of place. Some of the examples I've seen look quite neat and tidy. All things being equal, I'd like to do the same.

    I'm not sure what I'll do about the s/p switch for the mudbucker. There are some fairly small switches available, or I might be able to do something tricksy and hide it.

    The existing switch hole and location really bug me, the more I look at it. I may be able to plug the hole and do a "grain-match" job on the surface, or I may end up with some kind of metal cover plate - chrome or anodized aluminum - under all the controls. (This is not my first choice, but it could be done). My woodworking friend suggested that he could do a bit of marquetry inlay around the control area on the top side, and that might not look too bad, especially if I could find a complimentary piece of wood veneer for the scratch plate. It would certainly be unique.

    If I was using a 3rd pot for something, I'd just use a single pot with a push-pull switch on the backside. Maybe put in a rotary selector switch?

    As my pickups have not yet arrived, I've been fiddling around [on paper] with switch cascades and capacitor values - looking to see if I could incorporate a wider range of tone caps by messing about with putting just a few well-chosen values in series and parallel configurations.

    There's probably a good solution to this that will emerge once the pickups are in hand and I've had a chance to do some experimenting with the wiring, caps, etc.

    I've been plunking away at it quite a bit lately - lacking a bass amp, plunking quietly - and I must say I still really like the weight and feel of this bass. I had thought seriously at one point about just dumping it, but I think it can be made nice acoustically and cosmetically, with some skull sweat and elbow grease.

    On a completely different subject, has anyone ever heard of "ARIA" basses? There's one for sale here, the body is more or less a JB clone, and the pickups are a P-bass middle and a J-bass down at the bridge. It's currently covered in duct tape (the owner duct-taped his guitar strap to the body), but I think the wood is a solid piece - possibly Alder - not laminate or plywood or some other horror. It's been "spider-webbed" with foo-foo can laquer, but underneath there may be something decent. Just curious - I seem to be developing a knack for collecting oddball relics.

    Jim B
  20. P.S. here's a pic of a similar ARIA STB-Series bass to the one I was looking at. This one hasn't been "enhanced" with duct tape.... Owner's asking a hundred bucks and says that [SIC] "Volume nobs work, but are loose. Needs Strings."

    Attached Files: