The Last Bass Outpost

Ah, OK.  My monitor at home is the TV and it's not so great on the detail.

You are a lucky man - she even got you a white one. 

I was cleaning up the basement (making way for a new chest freezer) and I found my box of spare pups (I wasn't sure where I'd put those when I closed down the studio).

Anyway, I was glad to find that I have a full spare pair of LoZ bass pups (thought I just had one), as well as another gold geetar pup.  So I measured them all up.  Before we get to that, lets remind ourselves about the eternal LoZ bass wiring dilemma:  which wire colour is ground/hot (hot if from top coil; ground if from bottom) - Green or Brown/Orange?  

Why does this matter?  On a normal pup it wouldn't - as long as you wire all pups the same way in a given instrument it doesn't really make a difference as the coils are symetrical.  This is not the case with Gibson LoZ Bass pups (GLBPs?)  Because the coils are tapped like a transformer, the max length (hottest/bassiest tone position: green wire and brown/orange on each coil) will be the same no matter which way you wire it, the issue is positions 2 and 3, because the taps are not placed at perfect thirds along the coil. Think of it like this (assuming we straightened out the coil like Egon, of the Ghostbusters, did his slinky):

green                                               Blue           Red            Brown/Orange
|__________________________________|__________|_________|

If you use green as ground, positions 2 and 3 will be 'hotter" (higher impedance) than if you use brown as ground because the coil will have less turns/wire.  Drawing not to scale; exaggerated to illustrate.

This has been a point of confusion for some time because there have been 2 wiring diagrams for these basses floating around the net, which appear to indicate opposite wiring (* anybody actually have a GLBP with an orange vs brown lead or was whoever drew that diagram trippin/colourblind?):

This one shows orange (aka brown) as hot/ground:  http://grannygremlin.com/images/nonwebpics/projects/GibsonLoZ/LPTriumphDiagram.jpg

And this one shows green as hot/ground: http://grannygremlin.com/images/nonwebpics/projects/GibsonLoZ/LPTriumph-RecBass.pdf

Since this second one looks more legit (it is what Gibson provides on their schematics page), and due to the measurements below, I originally thought that this is the correct diagram.  I am no longer sure. ... though, the first diagram above is wrong about the location (tap point) of the green wire (green is definitely one end of the coil, not an inner tap as pictured).

There is a third diagram, definitely not by Gibson, which is very detailed and appears to show brown as hot/ground but I am not sure because I can't access it, only the thumbnail; see the colour coded one with "95" in the bottom left corner in google image search here.

The measurements (ranges given due to sample size of 4 pups and rounded off at both extremes, accounting for production variation):

Assuming Green is ground/hot:
brown - 112-119 Ohms
red    -   88-92  
blue   -   60-65

Assuming Brown (aka orange) is hot:
green  - 112-119 Ohms
blue    -  51- 56
red     -   24-27

Note that if you change which colour wire is hot/ground, that you also change which colour is position 2 (the coil is being used backwards so the smallest coil is not longer the smallest, but the medium length one).

Since the measurements with green as ground (I am getting tired of typing hot/ground, so from now on....) are higher (and the 'official' schem used that) I always assumed that this was correct.  This made sense further, because you wouldn't want too much of a output difference between positions 1 and 3. ... on the other hand, most things audio are logarithmic so using Brown as ground makes sense because then each position is pretty close to half the Z (DC R actually, but assuming Z is proportionate given it's the same coil, wire guage, magnet etc ) so that seems intentional in a way.  Also, this is the way Les himself appears to have wired them* (copied from the auction notes, though, to be fair, with the complete lack of consistent colour scheme in his pups, he is the one who may have had it backwards... though somehow I doubt it):

Pickup 1 Measurements
Orange: 114.2Ohms
Brown: 25.4Ohms
Red: 52.7Ohms
Purple: 158.3Ohms
Notes by Les Paul:
-BROWN    400T    -    Pos    1
-RED          800T    -       "      2
-ORANGE  600T    -       "      3
-SHIELD     GROUND
-YELLOW   400T    -       "      1
-GREEN     800T    -       "      2
-BLUE        1300T   -      "      3
-WHITE      HOT LEAD

Pickup 2  Measurements
Yellow: 52.3Ohms
Red: 25.2Ohms
Blue: 113.6Ohms
Notes by Les Paul:
-VIOLET      GROUND
-RED           400T    -    Pos   1      
-YELLOW    800T    -     "      2
-BLUE         1600T   -     "      3
-WHITE       HOT LEAD
-GREEN      400T    -    Pos   1
-PINK          800T    -        "     2
-GRAY        1300T   -       "     3

So that's something to think about. I am a bit curious to know if anyone out there has a LoZ bass with either:
- an orange wire instead of brown
- brown as ground (easiest way to tell is what colour wire goes from front pup to the pup selector switch).  I think mine is green, but I have to double check.

I measured my geetar pups to see if this would shed any light on the matter, but it didn't:  both of them are 10 Ohms  (nowhere close to any of the taps on the bass version... also explains the size difference) and that's with both coils in series vs individual coils as we are measuring here on the GLBPs.  Generally I find that the geetar versions appear to be better and more carefully made (the epoxy is neater, the DCRs match closer vs any of my 4 bass pups etc).  This may be because (as we like to joke) Gibson QCs anything geetar much better than anything bass, or something as straight forward as the bass version being more difficult to manufacture (due to it's increased complexity; the taps).

Other notes about Les' notes above: I think the "orange 600T" (bolded above) is a typo - should be 1600T.  It does appear to be written as such in the pics of the hand-written notes.  Another place where it appears that the seller may have made a transcription error is "gray 1300T" - it appears visible to me in the picture as "gray 1600T" which makes more sense since these are humbuckers and the coils should be identical.  The rest is too faded to be sure in the pics but it appears that the other "1300T" may actually be "1800T" in the hand-written notes (weird either way - could also be Les' typo, or a test of something different). Also, I have no idea what "purple 158.3 Ohms" is all about.*  It appears these are the seller's measurements so he may have been measuring 2 coils at a time there somehow.  He did not measure both coils in each pup so that's a shame.

* Since the seller apparently is the one who did the measuring, I am assuming he followed Les's notes as to which wires to use for hot and ground.  It would be reasonable to assume that he might have buggered this up somehow seeing as he did a 4th measurement on one pup, noted in the paragraph just above this one, that is well outside the range expected for the full coil of these pups.


Now on to sizes.

Geetar pups
Outer dimensions: 1 1/4" x 3 15/16"
Coil dimensions:    1"      x 3 5/8"


Production Bass pups
Outer dimensions: 1 1/2" x 4 5/16"
Coil Dimensions:   1 1/4" x 3 15/16"

Les' (prototype) Bass pups (estimated from auction pics with ruler)
1 3/8" x 4"

Note also that the prototypes seem to be very thoroughly/carefully epoxied, whereas the coils in the production versions have some windings peeking through here and there.  Also, all the leads (proto) come out of one spot vs opposite ends (prod).  Further, it appears that the coils are not aligned exactly on top of each other in the prod versions.  I postulate that this was done so that the wires from the bottom coil could be quickly and easily run up to the surface through the epoxy without bumping into the top copil or having to do something more complicated.  Les's pups might actually be a bit nicer in that they are made with more care, but I doubt it makes a huge sonic difference.  Anyway, electrically (design-wise), they appear to be the same as production models (with the possible exception of that one coil labelled as 1300T/1800T, whichever it really is).

Tell that the the 12th Fret - they're the best luthier shop in town (I'm sure you've heard of them as regards vintage sales) and it's what they use. This advice is straight from them and I've been following it for over a decade and all my instruments love it, as do those of my set up clients.

Tung WILL penetrate and condition and only forms a surface coating if profuse multiple coats are used (like seriously a lot - I have finished instruments and other odds and ends with it and it takes well over 10 coats to do that in any sort of detectable way).  A single coat (or even 2 if the wood is very dry - Canadian winters, eh) will penetrate into the wood and condition it (pores close up, hairline cracks, e.g. caused by excessive drying of the wood, even disappear etc). In fact, it is often one of the points brought up AGAINST using tung oil as a (for example) instrument finish - that it does not form a good protective surface layer easily.

Yes most products will have some drying agents in them, but these solvents are not always petroleum based - turpentine etc, though some use naptha - and in any case, they evaporate away leaving the natural wood oil to penetrate (their only purpose is to thin the oil  to make it easier to apply and penetrate the wood; less hand rubbing, i.e. friction heat to lower the oil viscosity is required).  It is not difficult to find pure linseed or tung oil either, but not required (the diluted kind is easier to use, pure is only required for food-safe applications; manufaturers recommend thinning it, at least for the first coat, if not for use in food-safe applications).

"the penetrating power of tung oil is excellent"
http://en.wikipedia.org/wiki/Tung_oil

Clean the board with 0000 steel wool (in direction of grain) and then tung oil (rub in until absorbed, also in direction of grain, wipe off excess, but often there isn't any).  Repeat oil application if you think the board will drink more/it's really dry and sucked up the first coat voraciously.

Just avoid anything petrolium based (like most actual 'fretboard polish' type products - also they're stupid expensive, especially the Gibson one).  That includes 'Lemon Oil' which isn't.  Any other actual plant-based oil (linseed etc) should also be fine, but I swear by tung (aka teak oil).

Hi Chromium, its a old Bogen M330 tube pa amp perched on the Tubeworks heads. I use it for the Rotating speakers in the 2 Leslies.

Those are great for LOZ Gibsons by the way, see mine (older model, but pretty much the same amp but without the balanced inputs and an, IMHO, cooler looking lunchbox style chassis) in the show your rig thread (also, due to the LoZ inputs, if you want a reeeeeeally overdriven guitar sound, plug something HiZ into there - everythuing past 3 is more crunch)

Don't recognize the logo and it's not very clear what it says:



Looks like a C and maybe an S next with an L on the end.  At first glance I thought Cort but that's not it.

...[googling "CSL bass"]

Yep:



" CSL was a brand name managed by Charles Summerfield Ltd England."
from: http://en.wikipedia.org/wiki/Ibanez

Some good views of a LoZ LP: