Les Paul Lo-Z pickups

[Louie Seven]

Hi ~

nice to see everyone.

Anyone here have an idea about Les Paul's specs for Low-Z pickups?

I'd like to know the impedance value of these pickups....

My understanding is that these were stacked dual coils.

I'd like to know what guage wire is in these units, roughly how many windings and or any combination of these questions.

Thank YOU,

Louie Seven

[Rosewood]

I haven't worked on one since 1983 so can't remember the dc resistance but it was wound with #28 wire on two stacked coils.

[Louie Seven]

OK! I'm halfway there!
THANKS!

Now, the way I figure it, EITHER the number of windings OR the DC resistance in ohms will get me there!

btw... I should have mentioned that I am aware that some of the Gibson Lo-Z Les Paul pickups are coil tapped and some were not.

Initially, (1969) the Les Paul Personal and the Les Paul Professional guitars employed Lo-Z pickups without any way to switch to hi-Z for regular amps.
Kind of an inconvience.

To rectify that problem, on the Les Paul Recording guitar (1971-79) they installed a hi/low impedance switch...which implies that they went ahead and fully wound the coils for hi-Z and coil tapped them at a MUCH lower value for the Lo-Z function.

I can't prove it, but it's logical to assume that the Personals and Professionals were not coil tapped and probably had considerably less windings than the Recording models.

Of course, the Lo-Z pickups that Les Paul hand-wound for his guitars back in the early 50's (the ones that he used to achieve all those amazing tones you hear on the Les and Mary hits on Capitol) were almost certainly not coil-split, (although some probably were, knowing Les) and the early ones were probably crude.

As the story goes, when Gibson and Les struck up their endorsement deal in 1952, he said, "I'll give you everything, EXCEPT my sound". What he meant was, I'll give you everything except Lo-Z pickups.

By 1968 he was willing to do that, and Gibson soon issued a succession of guitars and basses with Lo-z pickups.

Unfortunatley, it seems like only Les and Gibson know the real specs on those pickups. Gibson probably doesn't even know much more than what Les doled out to them.

Anybody have Les Pauls phone number? *haha*

I know you can buy off-the-shelf Lo-Z pickups from various mfgs....like EMG...
but I'm betting they don't get the same sound as what Les Paul was getting.

The reason I say that, is because EMG is marketing to players who want rock and contemporary sounds. Nobody wants the 'real' Les Paul sound ( I refer to Les Pauls recordings, not the Gibson Les Paul guitar, when I say that).

Thanks for listening..... I'm still interested in any input, or fragment of knowledge regarding this topic.

Regards,

Louie Seven

[Rosewood]

Louie, from what I remember the pickups were the same, they added a line matching transformer to give a hi-Z out.

[David Schwab]

I posted this somewhere in another thread. Les originally took the coil from an electric clock, which was round, and bent it into the oval shape of the pickup. I'm assuming this is where the idea of using such heavy wire came in. That was the pickup in "the Log."





On the '71 Triumph bass, the top and bottom coils each had four wires (red, blue, green & orange). I have the schematics from the guitars, but little is known about the pickups!

I'd love to get some to play with. If we knew the DC resistance, we sould deduce the number of turns... we know the diameter of the pickup, but we have no idea about the core size.

The volume control on the Recording guitar is 2.5K! The treble control is 1K and the bass control is 2.5K.

Two things to consider ... you can't wind that much 28 gauge wire on a bobbin, and they probably used large cobalt steel magnets.... but who knows!

Lo Z pickups are my thing. You don't need much wire on a Lo Z pickup. I'd make up a coil form, get some 28, and see how much you can wind. Don't be surprised it the pickup reads out under 500 ohms.

As a reference point, the early Alembic pickups used 40 gauge wire, and had 1,000 to 1,500 turns.

EMG pickups don't have low impedance coils, nor do they sound like it. They are high impedance coils with a buffer amp. So yeah, they sound like high Z pickups with more top end.

[DrStrangelove]

Anyone here have an idea about Les Paul's specs for Low-Z pickups?

Only a little.

Les Paul's Low-Z pups from the 70's were supposed to connect directly to a 600 ohm studio board,or so I mis-recall.

This means a 600 ohm impedance at 1000 Hz, not a 600 ohm DC resistance.

If the DCR is 500 ohm using #28 AWG, we can make a few guesses about the core size and estimate the windings accordingly.

If anyone has a spare pickup that could be X-rayed, so much the better.

-drh

[tbryanh]

Here is a nice website on the Les Paul Recording
http://www.ntw.net/~w0ui/family_webp...lrecording.htm

Here is a schematic of the inside of the guitar
http://www.guitar-parts.com/images/lespaul.jpg

[Louie Seven]

Only a little.

Les Paul's Low-Z pups from the 70's were supposed to connect directly to a 600 ohm studio board,or so I mis-recall.

This means a 600 ohm impedance at 1000 Hz, not a 600 ohm DC resistance.

If the DCR is 500 ohm using #28 AWG, we can make a few guesses about the core size and estimate the windings accordingly.

-drh

Do I understand correctly that you're suggesting the pickups are approximately 500 to 600 ohms DCR?

Regards . . . Louie

[David Schwab]

Only a little.

Les Paul's Low-Z pups from the 70's were supposed to connect directly to a 600 ohm studio board,or so I mis-recall.

This means a 600 ohm impedance at 1000 Hz, not a 600 ohm DC resistance.

If the DCR is 500 ohm using #28 AWG, we can make a few guesses about the core size and estimate the windings accordingly.

If anyone has a spare pickup that could be X-rayed, so much the better.

-drh

OK, just to be clear.. I said "don't be surprised if the pickups are 500 Ohms" ... I'm only saying this because I have no idea what the DC resistance is. But judging from the value of the pots, and the gauge of the wire... it makes sense.

Now the mixer input makes even more sense.

So they are probably about 500 Ohms.

[David Schwab]

Do I understand correctly that you're suggesting the pickups are approximately 500 to 600 ohms DCR?

Yes. Low impedance. Might even be 300 Ohms. Who knows. But low like that.

The very first pickup I wound was a P bass pickup, with 500 turns of 42 on each bobbin.

You need a transformer, or even better, a preamp. Then they sound fantastically clear. Very smooth and bright.

[DrStrangelove]

resistance ohms are not impedance ohms

Do I understand correctly that you're suggesting the pickups are approximately 500 to 600 ohms DCR?

A coil with a 600 ohm IMPEDANCE means that its DCR must be lower.

For example, loudspeakers are rated at 8 ohms impedance (a 1000 Hz) but have a DC resistance around 6 to 6.5 ohms.

Ohms are used for both DC resistance and impedance, but they are not the same.
Joe Gwinn can explain this a bit more clearly.

-drh

[dpm]

I worked on one of these a year or two ago and did take a DC reading back then but I never wrote it down. I have a distinct feeling the reading was about 500 ohms, though there's no way I can guarantee that and I could be totally wrong. I'll try to remember to check at work to see if anything did get scrawled somewhere....

[Joe Gwinn]

A coil with a 600 ohm IMPEDANCE means that its DCR must be lower.

For example, loudspeakers are rated at 8 ohms impedance (a 1000 Hz) but have a DC resistance around 6 to 6.5 ohms.

Ohms are used for both DC resistance and impedance, but they are not the same.
Joe Gwinn can explain this a bit more clearly.

It's true that in a passive system (no amplifiers) the AC resistance cannot be smaller than the DC resistance, by conservation of energy. Each kind of resistance represents an independent energy-loss mechanism. You can minimize energy loss, but you cannot make energy loss be negative (which would be energy gain).

With things that are intended for wideband use, unless it's a transformer, the AC resistance woun't be too much higher than the DC resistance, because the variation would cause the spectrum to be shaped.

In a pickup, we often want the spectrum to be shaped. But in a pickup intended to be flat, not coloring the sound, AC resistance cannot be too much larger than DC resistance.

In a transformer, the coils have very low DC resistance, and a primary inductance sufficiently high that the reactance at the lowest frequency of interest is at least five times the largest expected AC resistance, and what one is seeing as AC resistance is the load on the other side of the transformer.

The simplest way to see this is to take a 1:1 audio transformer. Small and cheap is OK. Hook the LCR meter to one winding. With the other winding open, measure inductance and AC resistance. One will measure the primary inductance and AC resistance being the sum of the coil's DC resistance plus something for losses in the transformer itself. Short the other winding. One will now measure the stray inductance of the primary winding, plus a slightly larger AC resistance. Connect a 10,000-ohm resistor across the other winding. One will now measure stray inductance plus AC resistance of about 10,000 ohms. In other words, the LCR meter is measuring the resistor through the transformer.

[J Martin]

Interesting topic. I have a Les Paul Professional and I have the Les Paul Bass pickups in my 1971 Jazz bass. The LP professional is two inches wider than a regular LP. I had to get a four inch wide strap so I could play it standing up. The LP Recording came out as a reduced cost model during the Nixon era price controls. Manufacturers couldn't raise prices on an existing models so they came out with models cheaper to make at the same or higher prices. It was much cheaper to assemble the controls on a plastic plate then to mount everything through the wood in the case of the LP recording. I had a friend who owned the LP Personal and that had a built in three pin mike jack on the upper bout. Good for solo work I guess. They also put a gold plated version of these pickups in some of the Gibson L5 S models. Another heavy solid body.

The Bass pickup is the one with the multiple coil taps. It has Three taps for a total of eight wires from the pickup and the bucking coil. I bought the 71 Jazz bass new in 71 just to put in the LP pickups. It went right from the store to the routing table. I still have it and it sounds fantastic.

I bought my LP Pro in 1973, but I had already been making my own low impedance pickups before that. I used ceramic bar magnets I got from Edmund Scientific and wound the bucker coil on an extra piece of steel that came with the magnets. I think I used #30 or #32 wire. I used what Gibson used to match the pickups to the amp, a Shure inline mic transformer. It worked best jumpered for 50 ohms. I molded the pickup assembly into a clay like substance that got baked in an oven at around 200 deg F.

[Louie Seven]

Interesting topic. I have a Les Paul Professional and I have the Les Paul Bass pickups in my 1971 Jazz bass. The LP professional is two inches wider than a regular LP. I had to get a four inch wide strap so I could play it standing up. The LP Recording came out as a reduced cost model during the Nixon era price controls. Manufacturers couldn't raise prices on an existing models so they came out with models cheaper to make at the same or higher prices. It was much cheaper to assemble the controls on a plastic plate then to mount everything through the wood in the case of the LP recording. I had a friend who owned the LP Personal and that had a built in three pin mike jack on the upper bout. Good for solo work I guess. They also put a gold plated version of these pickups in some of the Gibson L5 S models. Another heavy solid body.

The Bass pickup is the one with the multiple coil taps. It has Three taps for a total of eight wires from the pickup and the bucking coil. I bought the 71 Jazz bass new in 71 just to put in the LP pickups. It went right from the store to the routing table. I still have it and it sounds fantastic.

I bought my LP Pro in 1973, but I had already been making my own low impedance pickups before that. I used ceramic bar magnets I got from Edmund Scientific and wound the bucker coil on an extra piece of steel that came with the magnets. I think I used #30 or #32 wire. I used what Gibson used to match the pickups to the amp, a Shure inline mic transformer. It worked best jumpered for 50 ohms. I molded the pickup assembly into a clay like substance that got baked in an oven at around 200 deg F.

WOW! that's quite the info! Wondering if you'd be amenable to measuring the DC resistance of the pickups on your Lp Professional for me ? I'd be truly appreciative.

And btw, did you create a stacked hummer or a side-by-side hummer?
The Gibsons are stacked. But if a guy wanted to create Lo-Z pickups to install on a conventional Les Paul guitar, he'd want them to resemble conventional Humbuckers..dimensionally, that is.. so they fit the cavities without more routing etc...

Also, am I understanding that the Lo-Z pickups that you wound were about 50 ohms? (you mentioned that the Xformer worked best at that range)

THANKS, Louie Seven

thanks to everyone else too........this is very informative.