The Last Bass Outpost

Gear Discussion Forums => Bill's Shop: Projects, Mods & Repairs => Topic started by: Grog on December 07, 2013, 07:59:04 AM

Title: Modified Low Impedance Pickups??
Post by: Grog on December 07, 2013, 07:59:04 AM
I noticed this on Ebay, listed as bass pickups. One is a guitar pickup, but it has multiple wires coming out of it instead of two. Everything else looks like it came off of a Les Paul Bass. I wonder if they were rewound?? Specials from the Kalamazoo factory??

http://www.ebay.com/itm/Vintage-Gibson-Bass-Pickups-Bridge-Les-Paul-Truss-Rod-Cover-/370958584511?pt=Guitar_Accessories&hash=item565edacabf
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 07, 2013, 11:26:04 AM
Why do you think they're modified?
Look like perfectly normal bass pickups.
To me it looks like the one in the back is the same size just looks smaller in perspective.

Or am I missing something?
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 07, 2013, 11:44:10 AM
Look good to me (agree it's perspective - look at the pic of the bottoms; same size).  Nice low start - bid in (but this'll likely go higher than I can afford, and I think I still have one spare).
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on December 07, 2013, 11:57:57 AM
It might be perspective........ ??? The pickup on the left in the bottom shot still looks a bit smaller to me, though not as obvious as the top shot.  :-\

(http://i999.photobucket.com/albums/af119/Grog_03/GibsonBassPickups.jpg) (http://s999.photobucket.com/user/Grog_03/media/GibsonBassPickups.jpg.html)

Here is a shot I had on file of some of my spare pickups..........
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 07, 2013, 12:04:39 PM
Hey Grog, are those minibuckers from original (60s/70) EB3/EB2Ds? 

If so would you be willing to let one go - or at least the mounting ring?  The reissues (EPiphone at least... haven't hecked the SG Bass ones now that I think about it) are metric and just don't fit.
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on December 07, 2013, 02:07:00 PM
Hey Grog, are those minibuckers from original (60s/70) EB3/EB2Ds? 

If so would you be willing to let one go - or at least the mounting ring?  The reissues (EPiphone at least... haven't hecked the SG Bass ones now that I think about it) are metric and just don't fit.

I might be willing to let one go after the holidays.......... The rings alone do pop up on ebay from time to time.

http://www.ebay.com/itm/Vintage-Gibson-EB-3-Pickup-Ring-Mini-Bridge-1971-EB3-/190990569402?pt=Guitar&hash=item2c77eccfba
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 07, 2013, 02:59:18 PM
You sure, I haven't looked in a while (gave up) but all the ones I saw were Epiphone reissues (even a few marked as vintage).

Let me know after the holidays.
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 13, 2013, 10:02:31 AM
Did anyone here win the auction - winning bid was lower than I expected, but more than I could justify at the moment.
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 13, 2013, 03:44:56 PM
It wasn't me (for once)  8)
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on December 13, 2013, 05:12:19 PM
I didn't notice that it was from Owatonna, Minnesota. I bid for & won a Gibson GSS-100 that I was able to pick up from Owatonna, about an hour drive. Not many useful things pop up from Minnesota!
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on December 13, 2013, 05:57:24 PM
Anybody with deeeeeeep pockets?

http://www.ebay.com/itm/LES-PAUL-PROTOTYPE-HAND-MADE-PICKUPS-GIBSON-RECORDING-MODEL-BASS-GUITAR-PICKUP-/310813237742?pt=Guitar&hash=item485de9a1ee
Title: Re: Modified Low Impedance Pickups??
Post by: Dave W on December 13, 2013, 07:41:32 PM
... Not many useful things pop up from Minnesota!

I don't know about that. When I needed a tuner bushing for my EB-OF, one did pop up.  ;)

Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 14, 2013, 05:13:42 AM
Anybody with deeeeeeep pockets?

http://www.ebay.com/itm/LES-PAUL-PROTOTYPE-HAND-MADE-PICKUPS-GIBSON-RECORDING-MODEL-BASS-GUITAR-PICKUP-/310813237742?pt=Guitar&hash=item485de9a1ee

Wow!

How are you supposed to
Mount these??
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on December 14, 2013, 05:23:44 AM
Wow!

How are you supposed to
Mount these??

The idea was to hook up some brackets to some of the three point bridge bolts, maybe? :mrgreen:
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 14, 2013, 10:06:45 AM
Anybody with deeeeeeep pockets?

http://www.ebay.com/itm/LES-PAUL-PROTOTYPE-HAND-MADE-PICKUPS-GIBSON-RECORDING-MODEL-BASS-GUITAR-PICKUP-/310813237742?pt=Guitar&hash=item485de9a1ee

The hand-wrtitten notes on the back are very intersting; just frantically right-clicking and saving all thopse pics/text over on my end.  Gonna compare it to the notes I made about what wire was what and measurements of all coils when I had my Triumph apart years ago.  

Over the years I have seen so many folks rewire these pups and use the wrong wire for ground... and it doesn't help that Gibson wasn't so good at sticking to colour schemes to begin with.  Now we have a reliable benchmark (coil DCR) to compare to when looking at these things.

I am a little too excited about this!


Also, check out his custom built/modded basses at the bottom (also that SG is HOT.... and the archtop acoustics are making me feel so swoony - It's like looking at a prototype of me own Maude)!
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 16, 2013, 07:04:27 AM
I'ma try to compare these DCRs to my measurements later today, but about the mounting - there seem to be 2 options to me.  The first is that those 2 holes at opposite ends of the top are from screw mounting into the body wood under the pup (through the end loops of the coil?).  The other is that this is not all of the pup, let me explain:

Look at the pics with the ruler.  These pups are larger than the production guitar model but just a 1/4" or less smaller than the production bass versions.  It could be that this component fit inside the plastic (in production at least) embossed cover with the 3 mounting bushings.  Note how the entire exterior appears to be poured epoxy (so nicely formed of the front/sides and due to using a mould and a little less so on the rear due to the wires poking out and the open end of the form).
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 16, 2013, 07:40:19 AM
They look exactly similar to the ones Les Paul used in all his crude prototypes. Not as wide as the embossed gloss black ones with three lugs.

(http://i1289.photobucket.com/albums/b506/dtlaguitars/EBAY%202013/09%20SEPTEMBER%202013/Les%20Paul%20Prototype%20Pickups/Les_Paul_Custom_Pickups_033_zps8a73b44f.jpg)


And the "holes" on the top side of the pickup look like they tried to drill a hole. But they obviously didn't drill all the way through if you take a close look at the back sides.
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 16, 2013, 09:39:06 AM
Yeah - you're right about the holes - didn't think that one through, but I think you're wrong about the first bit - see the cherry EB2 - that pup ring looks mighty production-like (even down to the 3 pup screws and the 4 ring mount screws) and we already know that not all LoZ pups had the embossed logo (e.g. the white one). ... actually, that one looks like it might be a geetar pup due to size... ... none of the instruments pictured in that auction appear to have the embossed logo, even the 3-screw + ring mounted ones - check that sunburst geetar for example.

... looking at all of those basses more closely, it looks like the red EB2 has a differant style pup,  darker + ring + 3 screws, than the other... which appear to be mounted with just 2 screws each (top and bottom) vs 3 and do look very similar to this prototype (coulourwise)... so yeah, I take that back above (I wrote my earlier post as I read my coffee and without looking at the pics again, silly me, but I am so excited about this). They must have had some sort of cup they sat in, or a ring clamped around them with bushings to mount them like that.  I think I am still correct about these (more or less)  being what's inside the embossed cover of the production model though, just that LP himself was too impatient for them to sort that out and took matters into his own hands on some instruments apparently. ... though it would make sense from a production efficiency standpoint - if using the cover - to skip the mould when poring the epoxy and just pour directly into the cover.... but when did Gibson ever do things because they made sense?

I'd also like to see more detail on these basses - especially the 8 string, and particularly the bridge. ... Nice to see I'm not the only one sticking trapezes on to standard Gibby bridges on short scale instruments.

Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 16, 2013, 09:48:58 AM
Of course I meant the pickup on the 8-string prototype. Not the obvious factory one on the Red one. Sorry
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 16, 2013, 09:54:21 AM
None required  ;)
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on December 16, 2013, 10:29:59 AM
Lester's son, Rusty Paul is still playing a 1968ish modified EB-2 with low impedance pickups in his band............
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 16, 2013, 11:02:30 AM
O RLY? ...[google image]...

(http://morristowngreen.com/files/2011/08/SANY0307.jpg)

Doesn't look like any of thiose in the pic above, tough interestingly similar... unless they were further modified after the pics were taken.

Also, I can't find my write-up from when I measured one of my LoZ pups .... looks like I'm just gonna have to do it again.
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 17, 2013, 04:09:40 AM
What do you mean doesn't look like any of those in the pic above?
Looks a lot like the one on the left in the pic that I posted. Except for that red button.

Title: Re: Modified Low Impedance Pickups??
Post by: amptech on December 17, 2013, 08:27:07 AM
I thought it was the same bass ???
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 17, 2013, 09:06:24 AM
That's exactly what I meant - the red button on the top horn vs down below the bridge with the other knobs.  Could be the same bass with the button moved (as I insinuated), but we can't see the bottom half so who knows.  It is actually entirely likely that Les had another bass nearly identical (see the herd of LP Recordings - he was a fan of having plenty of spares once you found something you really liked, and of the 3 basses, this one looks to be the most developed/finished) that that wasn't part of the estate sale, and somewhat unlikely that Rusty is still using an instrument that was part of the estate sale (and ostensibly sold to someone besides him, because why would he have to buy it?).

... also the tuners are different (but those could have been changed out).
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on December 17, 2013, 11:37:34 AM
Maybe even a three point fridge bridge!
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 23, 2013, 11:26:46 AM
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 (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 (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 (https://www.google.ca/search?q=gibson+les+paul+bass+wiring&client=firefox-a&hs=3wp&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=OG64UsiaMNOysQTwuYGoCA&ved=0CDoQsAQ&biw=960&bih=728#facrc=_&imgdii=_&imgrc=xn7hrcV2-G0byM%3A%3B_STwZEN9utf16M%3Bhttp%253A%252F%252Fmusic-electronics-forum.com%252Fattachments%252F8196d1266941816-les-paul-triumph-bass.jpg%3Bhttp%253A%252F%252Fmusic-electronics-forum.com%252Ft3737-3%252F%3B1643%3B1226).

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).







Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 24, 2013, 04:06:45 AM
Wow that's quite a read Jake. I'm going  to have to read it a few times to make sure I understand what you're saying
;-)

I do seem to remember there are two generations of Gibson Lo-Z bass pickups.
They are identical, except for the colors of the wires.

Gr may stand for Green but also for Grey


When I get back home I'll look if I can find the exact colors


Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 24, 2013, 08:16:26 AM
Can't find it. All the pickups that I have here have the same colors.

Title: Re: Modified Low Impedance Pickups??
Post by: amptech on December 28, 2013, 03:15:19 AM



 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).



The set of four NOS guitar lo z i got, was of the bobbinless type - and had not passed QC. One had a broken ear, one was having visible wire through the epoxy and two were open. The open ones were misalligned, looked really weird.

But what was interesting was that one was 10 and one was 15 ohms, they are supposed to be about 10 for guitar.
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on December 28, 2013, 08:47:31 AM
I am told the red enamel wire that is in some cases visible on the bass lo-z pickups is actually not the functional wiring. It is supposedly isolation. Or so I'm told.
Anyone got ideas about this?
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on December 28, 2013, 09:17:28 AM
Can't speak for the bass pups, but i did dedicate the two broken ones to my personal research and development department. :)

I tried different methods; heating, soaking etc. but this stuff was impossible to remove without destroying the coils.
The thick enamel wire(red) was two equal winds (bobbinless) and it seemed to be no shielding except the mu metal plate (which is not connected
but isolated with blue tape) between the two coil windings.  The alnico magnets were quite large, good thick slugs of the rough sandcast type.
Both of the broken units had no bottom 'clip' , but the two working ones had clips - which might explain why they were so misalligned.
I did manage to chisel out the top winding on one of them as a whole (more or less) so I will try to make a replica when time allows me.
And since they had not been used, I can make a perfect cast of the pickup cover!
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on December 30, 2013, 08:56:33 AM
Interesting results.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 02, 2014, 10:43:55 PM
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 (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 (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 (https://www.google.ca/search?q=gibson+les+paul+bass+wiring&client=firefox-a&hs=3wp&rls=org.mozilla:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=OG64UsiaMNOysQTwuYGoCA&ved=0CDoQsAQ&biw=960&bih=728#facrc=_&imgdii=_&imgrc=xn7hrcV2-G0byM%3A%3B_STwZEN9utf16M%3Bhttp%253A%252F%252Fmusic-electronics-forum.com%252Fattachments%252F8196d1266941816-les-paul-triumph-bass.jpg%3Bhttp%253A%252F%252Fmusic-electronics-forum.com%252Ft3737-3%252F%3B1643%3B1226).

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).

Granny,

I have almost no training in electronics so I am not challenging you or the readings, but perhaps you could help me understand the schematic a little better.  I currently have Three recording basses that I am cleaning, two of which I am readying for sale.  I have two custom basses (one based on an eb body and one on a LP triumph only chambered) with recording bass pick ups in them  (one with original wiring and one custom wired to accept an Audere Preamp and Ghost piezo system) I also have two additional sets of Recording Bass Pickups and two additional complete wiring harnesses.  When I have taken the electronics out of these basses I kept careful notes as to how everything was wired even making little diagrams for myself (God forbid I forgot how to put them back together!)  In the all these where I removed and reassembled the electronics it has always been the same,

For the neck pick up the brown wires were connected to the ground and pick up terminals of the pick up selector.
For the Bridge pick up the brown wires were connected to each of the center lugs of the phase switch.  Then depending on which position the phase switch was in it altered which wire went to the other pick up selector terminal and which to the pick up selector ground.

The remaining wires (Red, green and blue) for both pick ups go to the Tone selector switch.  Each position on the Tone selector connects the same colored wires for each pick up together, leaving the other colors unconnected .  so

In one position Green and green from neck are connected/ green and green from bridge are connected

the two remaining positions connect Red Red for each pick up respectively and Blue Blue for each pick up.

I have disconnected the brown wire from the neck pickup going to the center lug (Ground}of the pick up selector and the Brown wire from the same pick up going to the one of the hot terminals of the pickup selector and taken a DC resistance measurement for these wires with the tone selector switch in each of its three positions.  Here is the readings that have been consistently returned for all my basses;

Red Red = 53-55 ohms
Blue Blue = 109-112 ohms
Green Green = 235-240 ohms

I do not know if this information is going to be of any use.  But I would like to get a better understanding of how these things truly work together.  I know how the wire them but sadly that is the full extent of my knowledge.  Any insight anyone could provide would be deeply appreciated.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 02, 2014, 10:49:08 PM
It might be perspective........ ??? The pickup on the left in the bottom shot still looks a bit smaller to me, though not as obvious as the top shot.  :-\

(http://i999.photobucket.com/albums/af119/Grog_03/GibsonBassPickups.jpg) (http://s999.photobucket.com/user/Grog_03/media/GibsonBassPickups.jpg.html)

Here is a shot I had on file of some of my spare pickups..........
Grog,

My God you have a little of everything!  It looks to me that you may have a Les Paul signature bass cream pickup in your possession.  I have been searching for one for almost a year with no luck.   I wonder if I could impose upon you to take a DC resistance measurement of that pick up (if indeed you have one)  I am curious as to what those numbers actually are.  It would clear up a question I had.
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 03, 2014, 09:25:57 AM
BlendedCat, that all sounds right as for what is connected where and agrees with both diagrams I posted (aside from the wire colour issue, which is the main crux of that diatribe of mine).  Sounds like you generally have it straight, if you have any further questions, let me know and I'll see if I can help.

Interesting to know that you have brown as ground/hot. ... [procrastination be damned; fetching screwdriver to check mine]... Yep, mine is wired with brown too (stock - I certainly never changed it, I think I've looked in there maybe once when I got the thing to fix the Hi/Lo Z tranny - it had come loose from it's cable clamp and was rattling around inside); I just always assumed, as mentioned in that long-winded post, that it would/should be green due to the Gibby schem.  Very interesting that they have it ass backwards (never found any errors in any of their other schems).

The reason your measurements are double* what I posted is that you are measuring the whole pup - that's 2 (ostensibly identical) coils in series.  I was just measuring a single coil at a time (so as to easier compare it to the measurements of Les' pups in the auction, because that's how they were measured, and also to give an idea of the production tolerance/variation between each coil).   You needn't have disconnected the wires to measure however - you could have got pretty much the same measurements from the output jack, though I salute your willingness to dive in there.  The way I did it was to measure the DC R across the green/brown wire to each of the other coloured wires for each single coil (first top then bottom; it's easy to tell what group of 4 wires is from each coil when you look at the bottom of the pup - opposite ends).  

* Your measurements are a bit more than double mine due to the other items in the circuit - I was measuring pups that were completely disconnected and removed from the instrument.

Lastly, we expect pics of your LoZ girls now that you've told us about them.


... now as regards your post at Grog - as far as I am aware, the LP Sig bass and geetar pups were the same - no difference. I have never compared the 2 side by side so I could be dead wrong.

Also, welcome to the Outpost.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 03, 2014, 09:55:34 PM
Yes!!  Thank you Granny, I understand a little better now.  I also have a LP recording guitar and have measured the pick up at 10K.  I suspected it might have been the one originally used in the LP Sig Bass and just changed in appearance for the later models.  Thanks for the confirmation.

Do you have, or have pictures of, or know anything about the multi tap transformer used in the LP Sig Bass?  Do you know if it is the same one used in the J Casady Bass?

You have me curious too if the pups from the new LP recording Guitar II limited edition are similar to the original (even though they have the coil taps).

I have read the help section and searched on posting pictures but I havent yet gotten a workable explanation.  When I figure it out I will get some pics up.
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on January 04, 2014, 09:20:02 AM
Grog,

My God you have a little of everything!  It looks to me that you may have a Les Paul signature bass cream pickup in your possession.  I have been searching for one for almost a year with no luck.   I wonder if I could impose upon you to take a DC resistance measurement of that pick up (if indeed you have one)  I am curious as to what those numbers actually are.  It would clear up a question I had.

That is a Les Paul Signature pickup. As Granny said, there is only one pickup for both bridge & neck on the guitar, and the same pickup is used on the bass. I believe it was designed by Bill Lawrence.  I took a reading between the two outside lugs, it ranged between 26.7 ohm to 25.3. I was getting 3.3 ohms touching the leads together at that setting. I waited years to score one of these and have only seen a few show up on eBay since.

(http://i999.photobucket.com/albums/af119/Grog_03/DSC08760_zps0998d848.jpg) (http://s999.photobucket.com/user/Grog_03/media/DSC08760_zps0998d848.jpg.html)
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 04, 2014, 11:57:13 AM
Yes!!  Thank you Granny, I understand a little better now.  I also have a LP recording guitar and have measured the pick up at 10K.

You're welcome. ...And I just did it myself when typing this post, so I will assume typo'd too, but that's 10 Ohms, not 10 000 (unless you measured off the HiZ output, then maybe something like that).

Do you have, or have pictures of, or know anything about the multi tap transformer used in the LP Sig Bass?  

The transformer in the LP and Triumph models is not the same as the multi-tap (3 taps on the primary side) transformer in the LP Sig.  The LP/Tri tranny has just a single tap on either side, a much simpler device that just converts the output level from loZ/mic to HiZ/standard instrument.  It is very easy to source and replace even today (use anything from the tranny inside a Shure/EV/alt brand barrel style Hi/lo Z converter 'winkie' for something pretty much identical to the original, or upgrade to a standard non-militarized tranny from Jensen, Sowter or Lundahl, to name the top 3 - anything they make for use in passive DIs will work, wired backwards; some of which I know will fit inside the body, others are too big, but can be used externally... Elcor is another option on the cheaper end).   The multi-tap tranny in the LP Sig is another matter.  You might be able to find something with the same ratios and primary taps (even if it has extra taps you don't need), but the chances of it being an easy fit inside the instrument are the main problem; unlike the other LoZ LPs, you gotta cram it in through an F Hole (right?  never got a good look at one).

The LP Sig uses the transformer slightly differantly than the other LoZ LPs. It is essentially, in addition to Z conversion, a varitone type switch opperating on the principle that changing the input Z coming into the (pre)amp will affect tone or at least drive.  It is not converting from Lo to Hi Z in a straight up aiming-for-nominal-level way that the other Loz LPs do.  My guess is that this was a simpler/cheaper way  of mimicing the original LoZ pups 3 coil lengths (note: same # of options), but I have never actually played (or measured) one so I don't know whether it really ends up being a similar effect (i.e. underwound plonk, normal balance, and overwound bass monster, comparitively speaking at least, settings); perhaps someone (ping Uwe) who has both can comment further on this score.

The only drawback to this approach (vs taps on the pups) being that these options were only available in HiZ mode, which is a shame when recording direct using the LoZ out  ... this does give me an idea for an additional option for replacement transformers: (after a lot of measuring of an original and a bit of math) one could get a transformer with 2 primary taps (corresponding to the normal and underwound settings; full bore would bypass the tranny) whose secondary output would still be in the LoZ range.  Then use a second tranny ( the simpler ubiquitous one) to convert to HiZ.

This has some advantages:
- all 3 tone options available in both Hi and Lo Z modes
- easier to source part (less complicated, 2 vs 3 primary taps required)
- likely to be smaller - easier to squeeze through an F hole into the body)
- if you like the sound of transformer saturation/distortion, cascading them like this is the way to get it

Either way (1 tranny or 2) you need something shielded, which limits replacement options further, though I suppose you could DIY a sheild.


Do you know if it is the same one used in the J Casady Bass?

Dunno.  I am not even sure how close the Cassidy pup is to the original.  I seem to recall people saying not so much (if so, then likely the tranny is different too), but I could be remembering wrong. If it is the same, I just may have wasted a bit of time above there re replacement options.




You have me curious too if the pups from the new LP recording Guitar II limited edition are similar to the original (even though they have the coil taps).

Indeed. I am curious to see measurements myself (I'd guess that position 2 will be in the 10Ohm range like the original, possibly a bit higher so that position 1 isn't too low, and position 3 will be more like the LP Sig pup at 25-30Ohms).


I have read the help section and searched on posting pictures but I havent yet gotten a workable explanation.  When I figure it out I will get some pics up.

Upload pics to  the host of your choice (Photobucket etc) then copy and paste the link into a post, highlight it and click the insert image button in the toolbar (or manually type image tags around it).

Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 10, 2014, 07:13:31 AM
Les' pups relisted at reasonable openning bid:

http://www.ebay.ca/itm/LES-PAUL-PROTOTYPE-HAND-MADE-PICKUPS-GIBSON-VINTAGE-PAF-BASS-GUITAR-PICKUP-/310839489388?ssPageName=ADME:B:WNARL:CA:1123

Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 20, 2014, 03:54:18 PM
That is a Les Paul Signature pickup. As Granny said, there is only one pickup for both bridge & neck on the guitar, and the same pickup is used on the bass. I believe it was designed by Bill Lawrence.  I took a reading between the two outside lugs, it ranged between 26.7 ohm to 25.3. I was getting 3.3 ohms touching the leads together at that setting. I waited years to score one of these and have only seen a few show up on eBay since.

(http://i999.photobucket.com/albums/af119/Grog_03/DSC08760_zps0998d848.jpg) (http://s999.photobucket.com/user/Grog_03/media/DSC08760_zps0998d848.jpg.html)

Thanks a ton for the information Grog, you couldn’t be timelier.  There was a Les Paul Signature pickup listed on Ebay that was DOA and would have to be rewound.   I bid to win figuring I would do some reverse engineering or give it to someone here on the site to analyze it.  Maybe it would be possible to duplicate?  When it arrived it didn’t look damaged so put on my magnifier headset and gently scraped away some the build-up on the bare wires going to the outside posts until they were shiny and clean.  Whoa, there was a continuity response and a subsequent DC resistance reading of 23 Ohms.

Based upon the readings you posted I think I came into possession of a working LP sig pickup for $122.00.  Pretty cool!
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 22, 2014, 09:15:17 AM
Congrats on the score.  Ebay is great sometimes for getting deals on stuff from sellers who don't know anything about the item or don't care/have the time to go over it properly.

Also, just for closure on the main topic, those prototype LoZ pups sold for about 1.8K after sitting pretty at a rather reasonable 250ish until the last hour.
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on January 22, 2014, 08:06:42 PM
Congrats on the LP Sig pickup, that was a great deal!! I happened to pull up the prototype pickups, just before the bidding ended. It was cheap most of the day, right up until the last ten seconds............... Then it hit $1,8K & ended.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 23, 2014, 01:35:28 AM
Those ended up being awfully expensive historical artifacts.

I hope I finally figured out the pic posting process.  Here are a few pic's of the two custom bass' I built that I referred to earlier and Granny asked me to show.  Grog and Granny, thank you again for sharing all that valuable insight and information. It was much appreciated.
(http://i1281.photobucket.com/albums/a520/rubelric/Mybass3_zpsb24e13d1.jpg) (http://s1281.photobucket.com/user/rubelric/media/Mybass3_zpsb24e13d1.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/Mybass10_zps2cef94cc.jpg) (http://s1281.photobucket.com/user/rubelric/media/Mybass10_zps2cef94cc.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/FullShotTilt_zps5d00c6ed.jpg) (http://s1281.photobucket.com/user/rubelric/media/FullShotTilt_zps5d00c6ed.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/FrontStraigton_zpseaa18970.jpg) (http://s1281.photobucket.com/user/rubelric/media/FrontStraigton_zpseaa18970.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/BottomHalfSide_zpsaa927700.jpg) (http://s1281.photobucket.com/user/rubelric/media/BottomHalfSide_zpsaa927700.jpg.html)
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on January 23, 2014, 02:19:54 AM
Those ended up being awfully expensive historical artifacts.

I hope I finally figured out the pic posting process.  Here are a few pic's of the two custom bass' I built that I referred to earlier and Granny asked me to show.  Grog and Granny, thank you again for sharing all that valuable insight and information. It was much appreciated.


That white EB will be the big brother of my christmas project, wich will also be white.
Looking good!
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on January 23, 2014, 05:47:19 AM
(http://i1281.photobucket.com/albums/a520/rubelric/FullShotTilt_zps5d00c6ed.jpg)

Wow that's a crazy cool bass!

Did you paint the pickups white? Or are they white plastic?
Title: Re: Modified Low Impedance Pickups??
Post by: drbassman on January 23, 2014, 06:04:02 AM
Wow, nice work!  I like the look of both of them.  How do they sound?
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 23, 2014, 09:19:12 AM

I hope I finally figured out the pic posting process.  Here are a few pic's of the two custom bass' I built that I referred to earlier and Granny asked me to show.  Grog and Granny, thank you again for sharing all that valuable insight and information. It was much appreciated.

I already appreciated the SG in the other thread, but that LP shaped one (is it actually a refinned Triumph or something else? Can't quite make out the headstock) is AMAZING!.  Love the colour and the postmodern pickgurad.  ... Not to mention the White LoZ pups (assuming they're from the LPSig Prototype - are they bass or guitar ones?)!  Just floored over here; seriously good work.  Please describe the controls you got there - looks like more than just the normal Triumph stuff.
Title: Re: Modified Low Impedance Pickups??
Post by: Highlander on January 23, 2014, 12:37:49 PM
Holy Mother of Pearl...! 8)
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on January 23, 2014, 02:22:06 PM


Wow that's a crazy cool bass!

Did you paint the pickups white? Or are they white plastic?

It seems, from the pics previous page that some white paint have peeled off the (black) neck pup.

They are Gibson embossed too, so then it can´t be LP sig protos, can they?
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 23, 2014, 03:43:54 PM
Good eye - I was so enthralled with the retro look of the thing (it's a really busy design) that I didn't notice that (in my defense it's on the opposite side of the body to that heavily loaded/decorated control cover).

Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 24, 2014, 06:30:47 PM
Sorry for the Delay in responding - I was out of town at a convention.  Thank you all for the kind comments.  Man- you guys make me feel good about the work I did on it!  Friends here don't play instruments and basically give me that "It’s really nice but why didn't you just buy one and save yourself the aggravation?"  :)  The white pickups are regular Triumph bass pickups that I dyed with SEM plastic infuser.  That spot isn’t a chip ( the SEM system which is used for Auto interiors is fairly indestructible) but a scrape from my file when I was doing the final fret level. I am a hack not a luthier and closer inspection of my work would confirm that.  Still I was so anxious to try it out that just left it for the time being.

The Body is the exact dimensions of the triumph.  I purchased a busted up one for pennies and used it as my model right down to the pocket depth  and such,  Then after I got it carved, sanded and routed perfectly I sliced the very top part off and chambered the bottom half taking nearly 1 ¼ pounds of weight out.  The color I used was the true 1957 Chevy Surf green,  not the later 62 Surf green which is what subsequent Chevy’s and Surf green guitars are formulated from.  The 57 color had a lot more blue in it and can be of indeterminate color sometimes appearing green or blue in depending on light.  I did a nod to the  “57 Chevy thing” which is why the three chrome stripes are on the Fin, er I a mean control panel.  The fingerboard is plain maple (left in its original unstained condition) which I bound and inlayed before glossing it.   I never seen such on a LP so I thought it would give it that “It looks like a Gibson but something’s wrong” feeling.  Same thing with the maple head plate which I Inlayed , painted and bound with a design  taken right from the Triumph bass layout.  Again Gibson never matched the headstock color to the body colors so I thought it was cool.  I agonized over whether to put the Gibson Logo on it.  It is not a Gibson and It might appear I was trying to rip them off.  But almost everything was inspired and Used from Gibson so to not acknowledge that seemed just as wrong. I researched the Laws and as long as I don’t claim it’s a Gibson and never try to sell it as such I can do what I wish with my property.   I tell people the truth about it – the name is on there as a true show of respect to the original and so they know that while I made it I did not create it.
(http://i1281.photobucket.com/albums/a520/rubelric/ControlPanel_zpsc425a42f.jpg) (http://s1281.photobucket.com/user/rubelric/media/ControlPanel_zpsc425a42f.jpg.html)
(http://i1281.photobucket.com/albums/a520/rubelric/What_zps379082bc.jpg) (http://s1281.photobucket.com/user/rubelric/media/What_zps379082bc.jpg.html)

Title: Re: Modified Low Impedance Pickups??
Post by: amptech on January 25, 2014, 04:13:26 AM
Plain crazyness…  great!
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on January 25, 2014, 06:12:08 AM
Nice work! You sure put a lot of thought, work & electronics in that bass! Any chance of seeing a gut shot?
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 25, 2014, 07:51:48 AM
Wow, I now remember you mentioning the preamp thing. 

Just one question:  what's the difference between the Z Mode switch and the Transformer switch (and what transformer did you use in there - LPSig or something else entirely?).... OK so that's 2 questions I guess.

That trhing is so snazzy I can almost overlook the maple fretboard  :P
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on January 25, 2014, 08:12:30 AM


That trhing is so snazzy I can almost overlook the maple fretboard  :P

Yeah. Almost!
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 25, 2014, 03:13:43 PM
Hahahahahaha  I like the maple finger Board  :mrgreen:  Actually it almost lost out to an ebony finger Board.  I’m terrible with design and colors so at every step of the finish I got a consensus decision from a set of people who are talented with such things.  To be sure I would offer the options but I would go with the consensus.  The finger rest opposite the pickups was a last minute option which won most to the maple.  Without the finger rest the maple didn’t work and the ebony was the clear winner

The transformer is an old multi tap audio transformer made in the 1960”s by UTC,  The one pictured  is Identical in shape but with different out puts and it matches the specs from the LP Sig Bass.  Because of the Ohm output of the pickups I had to use a different Tranny with a multi tap primary of 250, 500 and 750 ohms.
 
The Audere preamp is designed to accept only a high impedance input (hence the transformer).   It is one of the few preamps that uses active mixing were the pickups are buffered before the balance pot.  This prevents the resistance of the Balance pot from changing the start point of the attenuation frequency. It also allows for a customizable Z switch which changes the impedance load on the pickups effectively raising or lowering the resonant frequency of the pickups. (I hope I got this right !?!).  Any way the effect is that the balance pot really is sensitive and the sound of the pickups remain true regardless of the blend.  On the Z mode switch, the mid position of the Z switch is almost indistinguishable from my passive Triumph bass, the low position provide deep rich bass which is not boomy, the high  position is my slap bass setting.

http://www.audereaudio.com/index.htm

(http://i1281.photobucket.com/albums/a520/rubelric/photo2_zpscfdebc1f.jpg) (http://s1281.photobucket.com/user/rubelric/media/photo2_zpscfdebc1f.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/photo1_zps013f9739.jpg) (http://s1281.photobucket.com/user/rubelric/media/photo1_zps013f9739.jpg.html)
(http://i1281.photobucket.com/albums/a520/rubelric/photo3_zpsb92ccbab.jpg) (http://s1281.photobucket.com/user/rubelric/media/photo3_zpsb92ccbab.jpg.html)(http://i1281.photobucket.com/albums/a520/rubelric/photo4_zpsdd3b5c5f.jpg) (http://s1281.photobucket.com/user/rubelric/media/photo4_zpsdd3b5c5f.jpg.html)
It is obvious that all of this wouldn’t fit into the EBO slot head which is why I made this one.  I am finished making basses now.  I am not that good at it and It takes me forever (1 full year on the green one),
Title: Re: Modified Low Impedance Pickups??
Post by: Highlander on January 25, 2014, 04:14:27 PM
All that pasta...! :o
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on January 25, 2014, 05:55:06 PM
Lota stuff under that hood! Lester would be proud! Thanks for posting the photos......... :thumbsup:
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 26, 2014, 09:50:08 AM
Ah.  Thanks for those details... and pics.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on January 29, 2014, 02:58:43 AM
There are so many people interested in the low impedance pickups it would be good to post some additional information about them.  How would I go about getting xrays of the ones I have?  I have been asked to do it but I don't have a clue about how or where to make that happen.  Quite sure my health insurance wouldn't cover the xrays to be certain none of these pickups had a broken leg.  Can anyone offer a good suggestion?
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on January 29, 2014, 05:03:45 AM
There are so many people interested in the low impedance pickups it would be good to post some additional information about them.  How would I go about getting xrays of the ones I have?  I have been asked to do it but I don't have a clue about how or where to make that happen.  Quite sure my health insurance wouldn't cover the xrays to be certain none of these pickups had a broken leg.  Can anyone offer a good suggestion?

I guess flirting with a nice security guard at the airport is the obvious here.

But not for me though, I´m scared of flying - as well as my ´weak spot´for women in uniform probably would get
me arrested.

EDIT: I did open a Lo Z les paul pup, and think I posted a pic somewhere. Or are they still in the camera... I´ll check.
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on January 31, 2014, 08:35:25 AM
There are so many people interested in the low impedance pickups it would be good to post some additional information about them.  How would I go about getting xrays of the ones I have?  I have been asked to do it but I don't have a clue about how or where to make that happen.  Quite sure my health insurance wouldn't cover the xrays to be certain none of these pickups had a broken leg.  Can anyone offer a good suggestion?

Make friends with a medical researcher.

I work in a hospital (IT), but don't know anybody from either research or radiology well enough.

I am also not sure if there is much mystery left to the internals of these things: blade polepeice stacked humbucker with 3 taps in the coil. ... but I'd still be interested to see the guts for real in case of surprises/funny things - as long as a functional one doesn't have to be sacrificed in the bargain.

Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on February 03, 2014, 12:16:59 PM
Les' pups relisted again.  Not sure why relisted this time as they sold (for near what the seller asked as a BIN the first time) when he started the bid at $200-something the second time, but now back with a 3k BIN.  

http://www.ebay.ca/itm/LES-PAUL-PROTOTYPE-HAND-MADE-PICKUPS-GIBSON-VINTAGE-PAF-BASS-GUITAR-PICKUP-/350989506491?ssPageName=ADME:B:WNARL:CA:1123
Title: Re: Modified Low Impedance Pickups??
Post by: Highlander on February 03, 2014, 06:04:45 PM
I used the X-ray machine at a FedEx depot and posted it in my RD rebuild (stalled) some time back - to get anything decent you'd need a medical-quality machine...
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on February 08, 2014, 08:21:17 AM
My son & I took a run out to Dave's Guitar Shop in Lacrosse Wisconsin yesterday, I checked out the New Les Paul Recording II. I really didn't want to end up going home with it so I played it safe & didn't try it out.............
(http://i999.photobucket.com/albums/af119/Grog_03/Daves-1_zpsf7ca16fe.jpg) (http://s999.photobucket.com/user/Grog_03/media/Daves-1_zpsf7ca16fe.jpg.html)
While there, I notice a low impedance pickup in a display case by their checkout counter..........
(http://i999.photobucket.com/albums/af119/Grog_03/Dave-2_zpsbdb86d04.jpg) (http://s999.photobucket.com/user/Grog_03/media/Dave-2_zpsbdb86d04.jpg.html)
(http://i999.photobucket.com/albums/af119/Grog_03/Dave-3_zps4996148a.jpg) (http://s999.photobucket.com/user/Grog_03/media/Dave-3_zps4996148a.jpg.html)
Sounds like somebody gave Dave one of Lester's pickups purchased at the auction............
Title: Re: Modified Low Impedance Pickups??
Post by: Dave W on February 08, 2014, 09:00:02 AM
Or maybe Dave himself was the high bidder.
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on February 08, 2014, 09:20:37 AM
Or maybe Dave himself was the high bidder.

I didn't talk to Dave about it, the guy at the counter said it was given to him by a friend...........
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on February 08, 2014, 06:21:16 PM
Thanks a ton for the information Grog, you couldn’t be timelier.  There was a Les Paul Signature pickup listed on Ebay that was DOA and would have to be rewound.   I bid to win figuring I would do some reverse engineering or give it to someone here on the site to analyze it.  Maybe it would be possible to duplicate?  When it arrived it didn’t look damaged so put on my magnifier headset and gently scraped away some the build-up on the bare wires going to the outside posts until they were shiny and clean.  Whoa, there was a continuity response and a subsequent DC resistance reading of 23 Ohms.

Based upon the readings you posted I think I came into possession of a working LP sig pickup for $122.00.  Pretty cool!

I just made an offer & won a Les Paul Recording pickup, listed as dead, for $60.00. With a little luck, they just didn't know how to check it...... These pickups are pretty much bullet proof, unless it was defective from day one............ We'll see when it gets here.
Title: Re: Modified Low Impedance Pickups??
Post by: amptech on February 09, 2014, 03:08:21 AM
I just made an offer & won a Les Paul Recording pickup, listed as dead, for $60.00. With a little luck, they just didn't know how to check it...... These pickups are pretty much bullet proof, unless it was defective from day one............ We'll see when it gets here.

When they list them as shorted, buy them :)

But there are some open ones out there too…..
Title: Re: Modified Low Impedance Pickups??
Post by: Grog on February 12, 2014, 02:51:41 PM
The pickup came today, it measured at 10.7 ohms. I tested it with my transformer chord, stuck it close to a Les Paul, gave it a strum............It works fine! It has some old adhesive on it that Goo Gone is having trouble getting off......... I'll just keep soaking. A bargain for $60.00 these days!
Title: Re: Modified Low Impedance Pickups??
Post by: Psycho Bass Guy on February 12, 2014, 05:00:40 PM
It has some old adhesive on it that Goo Gone is having trouble getting off.

If you can find it, Goo Gone gel is MUCH better than the liquid.
Title: Re: Modified Low Impedance Pickups??
Post by: BlendedCat on February 14, 2014, 01:46:08 AM
The pickup came today, it measured at 10.7 ohms. I tested it with my transformer chord, stuck it close to a Les Paul, gave it a strum............It works fine! It has some old adhesive on it that Goo Gone is having trouble getting off......... I'll just keep soaking. A bargain for $60.00 these days!
Congratulations Grog.  That was one helluva bargain!  I am not sure where I am going to ultimately get there pick ups x rayed but there have been several people who felt it would be useful so one way or another........
Title: Re: Modified Low Impedance Pickups??
Post by: Granny Gremlin on February 14, 2014, 06:36:17 AM
Wasn't there some dude selling NOS LoZ pup bobbins on ebay a little while back?  Not sure if he even said if they were bass or guitar ones, but they were red plastic and had a slot for the rail polepeice IIRC.
Title: Re: Modified Low Impedance Pickups??
Post by: Basvarken on February 14, 2014, 09:02:53 AM
That was Greatdealz. But those were guitar size bobbins.