What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Hi Freefrog.

I wonder if the keeper was INITIALLY absent in Larry’s P.A.F. , BTW. Keeper bars are important for ‘’that P.A.F. tone’’ in my personal experience…

I have read comments about Larry Dimarzio's 1959 Les Paul Standard guitar having a unique distinctive tonality. I wonder if the absence of the keeper bar in Larry's PAFs is a contributor to this unique tonality.


FWIW, I’ve personally noticed a relative “immunity” to cable capacitance with vintage PU’s in general, at least with those that I find great (I’ve the memory of a L series Strat in my mind while I write that).

I think that one reason for the relative immunity to cable capacitance with vintage pickups is because of their lower impedance or DC resistance compared to the higher impedance modern pickups.
Higher impedance signals tend to be more noticeably affected by subsequent loading factors such as grounding resistance or grounding capacitance.

For example my Dimarzio X2N pickups wired up in the regular series humbucking operation (14K to 15K ohms range) are noticeably affected by a grounding capacitance as low as 1 nf, but when I wire up the Dimarzio X2N in parallel humbucking operation (approximately 3.5 K ohms range), the 1nf capacitance has much less effect.



Now, the effect of stray capacitance due to braided shielded wire is of course more than subtle… although I’ve personally found that it contributes to the sound when the pickups are in parallel in a Les Paul (situation involving several good lengths of inner wiring + four pots + a selector + a jack plug: in this case, parasitic capacitance appears to rise enough to shape in an unmistakable way the combined tones of the PU’s).

I have Dimarzio X2N pickups in my 2004 Gibson SG Standard guitar and the parasitic capacitance of the stock braided wires along with the push-pull potentiometers inside the SG control cavity noticeably affect the treble response of the X2N pickups.

I did an A/B listening comparison test between the sound of the X2N pickups inside my SG guitar and my other spare X2N pickups with my crude simple testing jig which includes a short shielded cable with alligator clips and a regular phono output jack which has a 500K ohms resistor in series with a 22 nf capacitor between the output lug and the ground lug of the phono jack, and a second 500K resistor wired up in parallel with the 500K resistor the the 22 nf capacitor combination in order to accurately simulate the loading effects on the pickup created by the 500K Volume control and the 500 K Tone control in Gibson and other similar type guitars.

With this set up, the X2N pickup mounted with the test jig sounded brighter and slightly louder than the X2N in my SG , and I interchanged and tested the X2N pickups in order to verify what they sound like , and they all sound the same so therefore the parasitic capacitance in the wiring in my SG is causing the X2N's treble response to roll off.

With this in mind, it would be better to use modern low capacitance wires inside guitars that have high output pickups in order to minimize the tone robbing parasitic capacitance.
However with PAF style pickups it is better to use the braided wires because the parasitic capacitance is a contributor to the vintage Gibson tonality.

Some people say that they can hear a noticeable difference on identical humbucker pickup models that have 4- conductor cable and braided single conductor cables.

I will be changing the pickups in a few of my guitars with better sounding Seymour Duncan and Dimarzio PAF style pickups, and I am wondering about whether I should replace the 4-conductor cables on these pickups with the braided single conductor cables as this is what the original PAF and Patent # and T-top pickups had so therefore if the parasitic capacitance of the braided single conductor cables on the PAF style pickups does affect the sound then it is a worthwhile modification to add the braided single conductor cables on my PAF style pickups because the practical approximation of the 1950's and 60's Gibson pickup tonality is what I am trying to get with my pickups.

I do like the switchable tonal options available on PAF style pickups which have the 4-conductor cables, including the series humbucking, the parallel humbucking operation and the phase reversal switching, but for the vast majority of the time I use the regular Gibson style series humbucking operation and with both the bridge and neck pickups in phase when the 3-way pickup switch is in the middle position so therefore the loss of the switchable tonal options on my PAF style pickups is not such a big deal for me because getting the typical vintage Gibson PAF sounds is the main priority.

However with my guitars that have the high output pickups, the switchable tonal options available with the 4-conductor cables is absolutely essential.


I also think that Wilde/Bill Lawrence designs and parts are extremely good. I’m more than happy to own a vintage L500 among ''a few'' other old things (like some “Seymourized” SH-1’s, prehistoric Duncan’s that I like a lot too)…

What is the difference between the "Seymourized" SH-1 and the regular SH-1 59 pickup?

Regarding high DCR with inductors: personally, I’ve no problem with that. When I put a home made Q filter in parallel with a PU, I like the LR readings to stay ‘’realistic’’ and I tend to ADD a resistor to achieve this result. My filter coils being shielded and wired as humbuckers, I’ve not noticed any issue with noise. YMMV.

I fully shield the inductor coils by covering them with aluminium tape which is grounded via the ground shield, and I also shield the guitar control cavity with copper tape in order to minimize any hum pickup, but even so there still is a mild hum with the Kent Armstrong Tone Choke when I use heavy gain overdrive, and this mild hum is dependent on where the guitar is located, however this hum noise is not as loud as what is produced by single coil pickups.

The 1970's Bill Lawrence 1.5 H inductor used in the Gibson L6-S guitars is a bumbucking inductor with the two coils fastened on to a metal screw which acts as the core, but the current production Bill Lawrence Wilde Q-filter inductors are single coil inductors , but even so they are noticeably quieter than the Kent Armstrong Tone Choke inductor, even with the high gain overdrive settings.

My own inductive Q-filter set up includes the inductor wired in series with a 47 nf capacitor which has a 10K resistor in parallel with the capacitor, followed by a 250K log push-pull potentiometer.
I have opened up the potentiometer and carefully scraped off the end section of the carbon track so that the potentiometer is converted to be a "no load" potentiometer which completely removes the Q-filter from the circuit when the dial is set to the fully clockwise position "10".

The push-pull switch of this 250K potentiometer shorts out the 47 nf capacitor/ 10K resistor in parallel combination thus bringing the inductor directly into the circuit for a stronger low/mid cut effect.

Even though the normal Gibson set up is with 500K log potentiometers, the 500K value is not so good for the Q-filter because most of the filtering happens at the lowest settings of the dial whilst the rest of the dial settings only have a subtle effect.
A 250K log potentiometer value allows a more controllable use of the Q-filter, but because the Q-filter effect can to some degree still be heard even when the dial is set to the fully clockwise position "10", I have solved this problem by converting the potentiometer into a "no load" potentiometer in order to be able to completely remove the Q-filter effect.

kziss.

 

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Hi uOpt.
Regarding how eddy currents affect the sound of pickups, an interesting factor that Bill Lawrence mentioned on his website is that along with the eddy currents that are caused by metals surrounding the pickup and also conductive metal tape wrapped around the pickups, another source of tone robbing eddy currents are the eddy currents created inside the pickup coils if there are internal shorts in the pickup coil which can happen because of the wires getting stretched and stressed as they go around the pressure points of the oblong coil bobbins during the coil winding process.

Bill Lawrence mentioned that the old formvar and plain enamel used on the wires in the old days was stronger and thus less susceptible to being damaged during the coil winding process than the thin and more delicate modern polyurethane lacquers used on the wires so therefore there were less issues with internal shorts in the pickups in the old days.

You can read about this in more detail here:

http://billlawrence.com/Pages/All_About_Tone.htm/TheVint_AgeBull.htm

The matter of eddy currents and avoiding internal shorts in the coil during the winding process is another hard to measure factor in the somewhat esoteric art of creating good sounding pickups.

kziss.

I think it is a mistake to focus on magnetism.

What matters here is Eddy Currents. Eddy Currents and their complexity as they form in a plate-like conductor that is layered with different conductive materials on top could easily be mind-blowing. Unfortunately measuring them is really, really annoying since you can't directly access them, and trying to observe them over the air makes you pick up your oscillating test field.

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

What is the difference between the "Seymourized" SH-1 and the regular SH-1 59 pickup?

Their specs are apparently the same when it comes to DCR and inductance but the comparison stops there IME.

The old "Seymourized" SH-1's that I've here are unpotted and have looser coils than modern ones.

Their slugs are made of unplated grey metal and their screw poles are threaded in their baseplates. They include long dark rough cast mags which are probably made of A5, according to their gauss readings and effect on the inductance. I suspect these mags to come from an old stock and to be of the same kind of original long A5 P.A.F. magnets that Throbak has tried to reproduce (= what he sells under the mention "A5 long oriented / mid dominant, focused tone, jazzy cleans").

These pickups haven't a crisp attack and couldn' generate the harsh high-range / boomy bass sometimes reproached to current SH-1's. They tend to sound smooth, compressed, tight and creamy, with a relatively narrow bandwidth when I compare them to an Early Pat pickup or to contemporary boutique P.A.F. replicas. They feature a nasal quality that I've often heard with A5 but also an unmistakable Duncan touch, giving 'em a warm tone. I like them for this "personality".

Thx for sharing your findings. I lack of time to comment what you say (not to mention that English is not my mother tongue) but we are roughly "on the same track". ;-)

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Hi uOpt.
Regarding how eddy currents affect the sound of pickups, an interesting factor that Bill Lawrence mentioned on his website is that along with the eddy currents that are caused by metals surrounding the pickup and also conductive metal tape wrapped around the pickups, another source of tone robbing eddy currents are the eddy currents created inside the pickup coils if there are internal shorts in the pickup coil which can happen because of the wires getting stretched and stressed as they go around the pressure points of the oblong coil bobbins during the coil winding process.

Bill Lawrence mentioned that the old formvar and plain enamel used on the wires in the old days was stronger and thus less susceptible to being damaged during the coil winding process than the thin and more delicate modern polyurethane lacquers used on the wires so therefore there were less issues with internal shorts in the pickups in the old days.

You can read about this in more detail here:

http://billlawrence.com/Pages/All_About_Tone.htm/TheVint_AgeBull.htm

The matter of eddy currents and avoiding internal shorts in the coil during the winding process is another hard to measure factor in the somewhat esoteric art of creating good sounding pickups.

kziss.

Yes, absolutely. And there can be conductive tape either on the outside of the coil, or the inside. Shielding too close to the pickup can also add.

I am, however, not comfortable with the term "tone-robbing". It is just a dampening effect, one of many, and a completely undampened guitar pickup would sound bad. The amplitude of the resonance peak would be way too high if you were to remove everything that dampens it. Think of a Stratocaster pickup with 1 Mohm pots (or no pots) and a very short cable into a high input impedance amp. That's not quite usable.

Another question is whether it is actually true that dampening from Eddy Currents sounds the same as dampening from a lower resistance volume pot. The simplest physics explaining the observations say it should, but who knows how that would out in practice.

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Another question is whether it is actually true that dampening from Eddy Currents sounds the same as dampening from a lower resistance volume pot. The simplest physics explaining the observations say it should, but who knows how that would out in practice.

I'd tend to think that Eddy Currents (or "courants de Foucault", as we name them here) alter the dynamics of a pickup in a special way.

I've once swapped some baseplates and the same pickup had a softer/slower attack with the materials supposed to favor Eddy Currents.

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

I'd tend to think that Eddy Currents (or "courants de Foucault", as we name them here) alter the dynamics of a pickup in a special way.

I've once swapped some baseplates and the same pickup had a softer/slower attack with the materials supposed to favor Eddy Currents.

Fair enough.

There also is the question of capacitance load. Does using a longer cable with higher capacitance do the same thing as a simple load capacitor (as in, the electrical element)?

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

There also is the question of capacitance load. Does using a longer cable with higher capacitance do the same thing as a simple load capacitor (as in, the electrical element)?

How many points can be won for the reply ? )

JK.

Short answer: ideally, I'd rather use a "delay line". But caps are much easier to find and do a decent job IMHO/IME...

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Delay line?

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

This:

http://www.datadelay.com/datasheets/1513.pdf

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Why would a cable add delay?

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Why not?

 

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Hi freefrog and uOpt.

Freefrog wrote:

The old "Seymourized" SH-1's that I've here are unpotted and have looser coils than modern ones...........

Thank you for the explanation about the "Seymourized" SH1.

Freefrog wrote:
I'd rather use a "delay line". But caps are much easier to find and do a decent job

The Paul Reed Smith guitars used a delay line on the "Sweet switch". I have never heard a Paul Reed Smith with the delay line Sweet switch set up this in person, but on a youtube clip someone demonstrated this and it sounded similar to a grounding capacitor.

Freefrog wrote:
I've once swapped some baseplates and the same pickup had a softer/slower attack with the materials supposed to favor Eddy Currents.

This is interesting. What were the actual pickups that you did this baseplate swap on ?
I once tested an Epiphone 57CH pickup with and without it's brass baseplate, but I could not hear any difference.

uOpt wrote:
Yes, absolutely. And there can be conductive tape either on the outside of the coil, or the inside. Shielding too close to the pickup can also add.
I am, however, not comfortable with the term "tone-robbing". It is just a dampening effect, one of many, and a completely undampened guitar pickup would sound bad.......

The Seymour Duncan JB pickups have copper tape around the coils. I have not yet tried out removing the copper tape from my JB to see if there is a difference in the sound.

With the term "tone robbing", I was referring to the fact that the eddy currents do dampen or darken the treble response thus creating an unintended loss of frequency response, however I do agree that treble loss or the dampening of excessive peaks can be a very good thing for some pickups. I do not like shrill or ice picky sounds so therefore the tone robbing in such pickups is a good thing.

I have two Bill Lawrence Wilde L500R (7.8K ohms 4 Henry) pickups on my 1998 Epiphone Japan Les Paul standard guitar, and these L500R pickups are basically in the PAF region, but they do have a more prominent upper midrange resonant peak compared to a more regular PAF style pickup, and this prominent peak can be a little too much, but when I turn down the Tone control to approximately the position 6 -7, this lessens the resonant peak and the L500R then sounds pretty much like a regular PAF style pickup.

Connecting a load resistor across the L500R also dampens the excessive resonant peak and again the L500R then sounds more like a typical PAF style pickup. The Q-filter also works well with the L500R pickup.

uOpt wrote:
There also is the question of capacitance load. Does using a longer cable with higher capacitance do the same thing as a simple load capacitor (as in, the electrical element)?

In my own experiments with this, the cable capacitance did sound similar to a simple loaded capacitor of the same value as the measured capacitance of the cable.
For example my 30 foot long Fender Koil Cord has a 1 nf capacitance, and my 100 foot long cable has an 8nf capacitance, and when I connected my 4 meter long cable whose measured capacitance is in the 400pf to 500 pf region, I then added additional grounding capacitors at the output side of this cable and I got a similar tonal response as what the higher capacitance cables produced.

kziss.

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

The Paul Reed Smith guitars used a delay line on the "Sweet switch". I have never heard a Paul Reed Smith with the delay line Sweet switch set up this in person, but on a youtube clip someone demonstrated this and it sounded similar to a grounding capacitor.

To my own ears, the phase shift due to this component sounds slightly more natural and "cable alike" than with a mere cap (and I think that PRS would have used a capacitor if it wasn't the case). Even if for convenience, I personally use simple caps.

This is interesting. What were the actual pickups that you did this baseplate swap on ?
I once tested an Epiphone 57CH pickup with and without it's brass baseplate, but I could not hear any difference.

Let's simply say that it was a P.A.F. replica with underwound & unpotted hand guided coils. And the difference of dynamics was rather clear in this case.

Now, when I've recently tried to upgrade a cheap Ibanez HB with an alnico mag and a nickel silver baseplate, it has not changed its (lack of) attack nor improved its muddy sound at all. The owner has finally decided to ditch it. :-/

 

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

To my own ears, the phase shift due to this component sounds slightly more natural and "cable alike" than with a mere cap (and I think that PRS would have used a capacitor if it wasn't the case). Even if for convenience, I personally use simple caps.

I read on an article about PRS guitars that the particular delay line based Sweet Switch circuit is very heavily dependent on the actual pickups that were used in the early era PRS guitars so that if you changed the pickups on the guitar, then the Sweet Switch effect may now sound very subtle or it might not be noticeable at all.

Apparently the original PRS pickups were very bright sounding and Carlos Santana disliked this brightness and he felt that they needed to be tamed down and Paul Reed Smith then came up with the delay line Sweet Switch circuit which apparently was developed by Eric Pritchard.
I am not sure what kind of Sweet Switch circuit the current PRS guitars use.


Let's simply say that it was a P.A.F. replica with underwound & unpotted hand guided coils. And the difference of dynamics was rather clear in this case.

Now, when I've recently tried to upgrade a cheap Ibanez HB with an alnico mag and a nickel silver baseplate, it has not changed its (lack of) attack nor improved its muddy sound at all. The owner has finally decided to ditch it. :-/[/QUOTE]


I have a very cheaply bought (around $10) Ibanez pickup (INF-1 or INF-4) whose DC reading is in the 8K region and which if I remember correctly has an alnico magnet, and similar to the Epiphone 57CH pickups, this Ibanez INF pickup also has a muddy sound with a darker treble response which other people have mentioned and complained about. This pickup is boring sounding for clean sounds, but it is OK for smooth heavy overdriven sounds or the mellow "woman tone " style overdrive sounds.

kziss.

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Most times I hear "sweet <xyz>" for <xyz> being a (switch|circuit) in a passive environment it is some form of LCR network. I wouldn't characterize it as a delay of any sort, and it certain has nothing in common with higher cable load.

An LCR network is still a nice trick. It is one of the purely passive circuits that can move the sound at all. I have one in my Strat which is supposed to be Blackmore-ish anyway.

 

[freefrog]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

Most times I hear "sweet <xyz>" for <xyz> being a (switch|circuit) in a passive environment it is some form of LCR network. I wouldn't characterize it as a delay of any sort, and it certain has nothing in common with higher cable load.

Yes, the sweet switch works on a different principle. http://prsguitars.com/forum/showthread.php?839-How-a-quot-Sweet-Switch-quot-really-works

And IME, it has certainly something in common with long cables : the tone, with this "je ne sais quoi" of natural missing in simple capacitive loads.

An LCR network is still a nice trick. It is one of the purely passive circuits that can move the sound at all. I have one in my Strat which is supposed to be Blackmore-ish anyway.

Having different guitars with various kinds of LRC passive circuits, I agree.

I have a very cheaply bought (around $10) Ibanez pickup (INF-1 or INF-4) whose DC reading is in the 8K region and which if I remember correctly has an alnico magnet, and similar to the Epiphone 57CH pickups, this Ibanez INF pickup also has a muddy sound with a darker treble response which other people have mentioned and complained about. This pickup is boring sounding for clean sounds, but it is OK for smooth heavy overdriven sounds or the mellow "woman tone " style overdrive sounds.

I periodically force myself to practice on my cheapest guitar and I find a perverse pleasure to get a good tone from MIC pickups with ceramic mags. So, don't tend to dismiss "cheap" pickups. But after that, it's still a bliss for me to play on a good P.A.F. replica or on a pat. sticker. ;-)

 

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

uOpt wrote:
An LCR network is still a nice trick. It is one of the purely passive circuits that can move the sound at all. I have one in my Strat which is supposed to be Blackmore-ish anyway.

Hi uOpt.
What are the component values of the LCR circuit in your Strat ?

kziss.

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

uOpt wrote:
An LCR network is still a nice trick. It is one of the purely passive circuits that can move the sound at all. I have one in my Strat which is supposed to be Blackmore-ish anyway.

Hi uOpt.
What are the component values of the LCR circuit in your Strat ?

kziss.

Hmm, I need to look actually. It is the Bill Lawrence Q-filter with some values for capacitor and resistor that I got who knows where. I need to look at that guitar anyway.

Whatever I have, it is pretty subtle, I think I will do a beefup when thingie is apart anyway.

 

[kziss]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

uOpt wrote:

Hmm, I need to look actually. It is the Bill Lawrence Q-filter with some values for capacitor and resistor that I got who knows where. I need to look at that guitar anyway.

Whatever I have, it is pretty subtle, I think I will do a beefup when thingie is apart anyway.

Hi uOpt.
From what I have seen on the Bill Lawrence website, his recommendation for the Q filter was to use the inductor in series with a parallel combination a 22 nf capacitor and a 10K or 20K resistor, and a 250K potentiometer can control the depth of the Q-filter effect. I like to use a 250K log "No load" potentiometer so that I can get a reasonable control rotation tapering of the Q-filter effect and then have the Q-filter completely out of circuit when the potentiometer dial is set to the fully clockwise position "10".

Ritchie Blackmore's tech John "Dawk" Stillwell had wired up some kind of variation of a Q-filter type control called the Master Tone Control (MTC) in Ritchie's Stratocaster guitars. John still makes and sells the MTC which is enclosed in black epoxy. I have never come across the MTC, but from what I have seen in an installation diagram, it might possibly be an LCR filter similar to the Q-filter but of unknown inductor, capacitor and resistor values whose depth is controlled by one of the potentiometers on a Stratocaster that previously was one of the two Tone controls, and there are also two other wires that come out of the MTC which are connected to the two signal pins of the Volume control potentiometer so therefore I assume that this is a treble bypass capacitor or a capacitor/ resistor combination which comes into effect when the Volume control is turned down.
kziss.

 

[uOpt]

Re: What was the metal composition of the 1950's and 60's Gibson humbucker covers ?

uOpt wrote:


Hi uOpt.
From what I have seen on the Bill Lawrence website, his recommendation for the Q filter was to use the inductor in series with a parallel combination a 22 nf capacitor and a 10K or 20K resistor, and a 250K potentiometer can control the depth of the Q-filter effect. I like to use a 250K log "No load" potentiometer so that I can get a reasonable control rotation tapering of the Q-filter effect and then have the Q-filter completely out of circuit when the potentiometer dial is set to the fully clockwise position "10".

Ritchie Blackmore's tech John "Dawk" Stillwell had wired up some kind of variation of a Q-filter type control called the Master Tone Control (MTC) in Ritchie's Stratocaster guitars. John still makes and sells the MTC which is enclosed in black epoxy. I have never come across the MTC, but from what I have seen in an installation diagram, it might possibly be an LCR filter similar to the Q-filter but of unknown inductor, capacitor and resistor values whose depth is controlled by one of the potentiometers on a Stratocaster that previously was one of the two Tone controls, and there are also two other wires that come out of the MTC which are connected to the two signal pins of the Volume control potentiometer so therefore I assume that this is a treble bypass capacitor or a capacitor/ resistor combination which comes into effect when the Volume control is turned down.
kziss.

Yupp on all points.

A Dawk MTC went through ebay a while back but my snipe wasn't high enough. I generally don't like that sort of voodoo'n'epoxy style of business.

I have a pickup test harness with all kinds of different controls on rotary switches. It has another Lawrence Q filter. I should really put it into a bigger housing and then have a 12-point rotary switch for different capacitor values and use a potentiometer instead of just a resistor.

I really need some rewriting because I put that white Strat together after getting no-load pots for tone and LCR - but then forgot to use them

<<= easily confused