Zexcoil pickups

[Mike Sulzer]

Its a cool design I guess, but must be hell to make those things. The resonant peak video is a little whacked in my opinion, you can lower the resonant peak with a little thing called a tone control or change your tone caps or pots;

A resonance has both Q (that is, width and height) and center frequency. You certainly cannot change both those parameters in an independent way with a single tone control, and so of course you cannot make one pickup sound like another with a tone control. And so I think you are misunderstanding how much the frequency response actually determines when you do have independent control of both as Scott does.

That said, I do think Scott's video is a bit misleading. It appears that the pickup is a bandpass filter. It is not, it is a resonant low pass filter. However, the induced voltage increases proportional to frequency due to the derivative in the law of induction, making it look as though you have a bandpass filter. If this effecct is taken out, you can see much more about the details of the actual response of the circuit.

[ScottA]

That said, I do think Scott's video is a bit misleading. It appears that the pickup is a bandpass filter. It is not, it is a resonant low pass filter. However, the induced voltage increases proportional to frequency due to the derivative in the law of induction, making it look as though you have a bandpass filter. If this effecct is taken out, you can see much more about the details of the actual response of the circuit.

I'm not sure how you can construe my video as "misleading". I think that is an extremely unfair thing to say and sets a bad precedent.

The data are the data.

Other than some normalization and baseline subtraction (and only in certain cases to facilitate the comparisons), the data presented are as collected. We can argue about the interpretation of the data (which I really don't even get into in the video), but to call it "misleading" I think is off base.

I certainly am not trying to mislead with any of the information presented, in fact quite to the contrary the whole point of making that video was an attempt to clarify. I will say that I am coming at things from a different perspective, enabled and necessitated by the unique challenges of my designs, but I think when you see the whole story presented you will agree as to the utility (but again, this won't happen for awhile).

Anyway, I hope you guys don't interpret my responses as too combative, I like this place and I respect a lot of the people that post here. I just honestly am trying to relay information as to where my designs fit in the landscape of what people already are familiar with.

[tmenss]

The single most important thing the Zexcoil 101 video helped me with is to look at peak resonance (PR) plots differently. Not that my notions are correct since I have but very sketchy understanding of what it takes to make a pickup, but I'm investigating another approach to using such information. When I first saw such PR plots it made me think all you pickup makers are crazy, "Who in their right mind would try to make such a specific filter by winding hair thin wire onto a coil." No real science except perhaps the thousand monkey theorem. But I digress, getting back to the PR plot, the Zexcoil video indicated that, "frequencies above the line are filtered and the ones below it are passed." My little mind immediately associated that imagery with the sensitometric curves used in photography, called the Zone system. So in relating that method (I know I'm stretching the analogy) back to PR plots and Zexcoil technology, there are certain aspects of frequency measurements and Zexcoils technology that imply an ability to control "zones of tones". Another aspect of the Zone system that I believe relevant is that it accommodates a visual perceptual model to make it practicable. Though it defines 10 distinct, visually identifiable and sensitometrically measurable zones, it is primarily occupied with structuring the control methodologies to 5 zones. So relating this back to plots, the peak resonance point itself best serves a mathematical purpose for calculating internal capacitance and not overall pickup behavior. But it can still provide information for modeling which can consist of subdividing for example a 100-10000 hz bandwidth into octaves, then select a midpoint band and a few octaves above and below that midband. In my analogy, these bands “zones of tones” can be analyzed in relation to either a specific PR reference plot or a calibrated pink noise plot for deviations. I have no idea what analysis method would, should or could work but in my mind I somehow think the method should consider two factors in the analysis: the area of the bandwidth "zone" under the curve and the slope of the curve itself. The analogy with sensitometry is close with the method I described. There is a “density of frequencies” measure and there is a “contrast” of the relationships of the sub frequencies contained therein the slope of the curve bounding the top frequencies. Now I think this gives significantly more information from which to design upon. Given this information, it appears intuitive to me that a multiple coil approach to conforming to target zones is, if not highly practical, then at its least indicative that one monkey wants to beat the system. So here's everyone's chance, am I the crazy?

The above statements are solely those of tmenss, an inexperienced winder and sometime prowler of information contained on MEF. No monkeys real or imagined were harmed during the formation of this post. Enjoy at your own peril.

[Mike Sulzer]

I'm not sure how you can construe my video as "misleading".

OK, I went back and looked at again. This is what I see now. The pickup circuit is indeed a filter, as you say, but it does not function as you say. Your claim is that the filter has low gain at low and high frequencies and approximately unity gain at the resonant frequency. That is because you are measuring a parallel resonant circuit (presumably with a series resistor from the generator or some such arrangement) and think that is the circuit of the pickup. It is not. In the pickup, the voltage source is in series with the inductor. The inductor then is connected to a shunt capacitor (which in real life includes the cable capacitance). This is a two pole low pass filter. It has unity gain at low frequencies, and the gain falls off at 12 db per decade at high frequencies. This filter has a high enough Q to have a resonant peak. At this peak, the gain is several to maybe 10 db above unity.

So you have not described how the resonant pickup filter works, you have described how your measurement of the externally accessible parallel resonant circuit works. Obviously you can convert from one to the other with a bit of computation.

(I had initially thought you were measuring the pickup response with a coil and you were seeing the law of induction at work, but your description of unity gain at the resonance indicates that you are looking at the parallel resonance. There is nothing wrong with looking at the parallel resonance; it is how you measure the coil characteristics. But it is not the same as the pickup filter, which is what you are trying to describe.)

[ScottA]

Mike,

See, I told you I respected a lot of people who post on this forum!

Regardless of the technical correctness of my description of the measurement in the video, the information that I require to characterize and compare the performance of the pickup is embedded in the data, and I can get out of these measurements what I need. What I have been able to do is to find some pretty interesting patterns and responses in the data and tie them back to a basic physical model for tonality. Anyway, I'm not an electrical engineer (I'm a chemical engineer by education), but I'm trying to pick up what I need from the discipline as I go, and I appreciate your clarification. Maybe I should run my draft by you when I get this stuff written up and you can make sure I'm not saying anything stupid!

Sincerely,

Scott

OK, I went back and looked at again. This is what I see now. The pickup circuit is indeed a filter, as you say, but it does not function as you say. Your claim is that the filter has low gain at low and high frequencies and approximately unity gain at the resonant frequency. That is because you are measuring a parallel resonant circuit (presumably with a series resistor from the generator or some such arrangement) and think that is the circuit of the pickup. It is not. In the pickup, the voltage source is in series with the inductor. The inductor then is connected to a shunt capacitor (which in real life includes the cable capacitance). This is a two pole low pass filter. It has unity gain at low frequencies, and the gain falls off at 12 db per decade at high frequencies. This filter has a high enough Q to have a resonant peak. At this peak, the gain is several to maybe 10 db above unity.

So you have not described how the resonant pickup filter works, you have described how your measurement of the externally accessible parallel resonant circuit works. Obviously you can convert from one to the other with a bit of computation.

(I had initially thought you were measuring the pickup response with a coil and you were seeing the law of induction at work, but your description of unity gain at the resonance indicates that you are looking at the parallel resonance. There is nothing wrong with looking at the parallel resonance; it is how you measure the coil characteristics. But it is not the same as the pickup filter, which is what you are trying to describe.)

[Possum]

The video isn't misleading, its just old hat stuff alot of us have already dealt with, players may be impressed with it or more likely won't watch the whole video because of information overload is more likely. I have the Syscomp and also have used a bunch of software oscilloscopes before that and frankly, doing those plots is amusing but not all that useful. I've only used it to spot tiny differences in resonant peak in prototypes, but the bottom line in the end is does the pickup sound good. Good tone is something you can't chart or measure. I'm not a fan of 44 gauge and thinner wire coupled with blades, I do make one such product but it is very low tech and frankly few buy it despite my being pretty happy with it. I think thats the point I was trying to get across about Barden's tone sharing that kind of sound, its about impossible to get away from. Lawrence pickups use the same ideas but he uses some tricky magnetic alloys which help alot, Dave probably knows more about that than I do. But I've had Lawrence's and EMG's stuff and in the end you just can't beat a noisy pickup wound with 42 gauge wire, thats my opinion, there's a wamth and transparency that goes away with the thin wire gauges, so for me I avoid going that route. I'm working on that P90 housing sized sidewinder and if I can't nail it with 42 gauge I'll abandon it, using thin wire to drop the AC resistance and peak rez is a no no in my design book. I don't mean that as a slap in the face, its just not to my own tastes. I think your idea is very cool, the bottom line is how well it sells, most guitar players are very traditional and I suppose I'm one of them; I've bought several high tech pickup designs and had EMG as a client for 14 years, but I always come back to simple noisy pickups that are just luscious and juicy in comparison.

[Mike Sulzer]

...just old hat stuff alot of us have already dealt with,...

You sure you know enough about these things to dismiss them like that? I would have thought not based on what you have written.

[David Schwab]

I'm not a fan of 44 gauge and thinner wire coupled with blades, I do make one such product but it is very low tech and frankly few buy it despite my being pretty happy with it. I think thats the point I was trying to get across about Barden's tone sharing that kind of sound, its about impossible to get away from. Lawrence pickups use the same ideas but he uses some tricky magnetic alloys which help alot, Dave probably knows more about that than I do. But I've had Lawrence's and EMG's stuff and in the end you just can't beat a noisy pickup wound with 42 gauge wire, thats my opinion, there's a wamth and transparency that goes away with the thin wire gauges, so for me I avoid going that route. I'm working on that P90 housing sized sidewinder and if I can't nail it with 42 gauge I'll abandon it, using thin wire to drop the AC resistance and peak rez is a no no in my design book.

Barden uses 43 AWG wire, as does EMG on some of the pickups. The only reason why you would use 43 or 44 wire is you don't have much room to wind onto, or, you want more mids and a tighter low end. Or you want to wind a butt load of wire. Barden could probably use 42, because he doesn't wind a whole lot of wire on the pickups. So he might have used it for a certain tone.

I agree about 42 though. It produces more low end and has less pronounced mids. At 43 and higher you start to bump the mids up. 41 and 40 are even rounder sounding, but now the problem that necessitated using thinner wire in the first place rears its ugly head; You run out of room if you are making replacement pickups. You can probably make a great sounding stack or what have you if you didn't have to fit them into a Strat pickup case. The old Lawrence L-250s are a good example. They are decent sounding sidewinders, but lack some of the snap in the top end when used in some guitars. But they sounded very nice in my Mustang. But then Bill seems to like smooth treble in his pickups. He calls it "sweetness".

Lately I've been making some mini humbucker size bass pickups for use in Gibson basses. I ended up using taller bobbins so I could wind 42 gauge wire of them, and still get them to where I wanted them. I liked that tone better than using 43. 44 is an odd wire because you can use it to darken the tone up, once you get out of Ric/DeArmond territory. So sometimes it's better than using 43.

I think the Zexcoils sound good. They sound like single coils to me, but maybe a little brighter. I especially like the Tele bridge pickup. But as I always say, take two real single coil Strat pickups wound with 42 and using alnico magnets, and they have the potential to sound like night and day. So there isn't one correct tone. Dual blade single coil size humbuckers like Bardens and Duncans sound pretty close to single coils, but lack the high end extension due to phase cancelation. I make dual rail Jazz bass pickups as well as sidewinders, and the sidewinders nail the single coil high end.

So if you think about the market you are shooting for, people who want vintage might not want blades and thinner wire or anything but alnico. But there are a lot of other players who like more modern tones and don't like hum. I talk to them all the time.

[Possum]

I think the market for these would be the jazz fusion guys, and the neo-classical rock shredders, maybe some metal guys, the thing they all have in common is they are all hum-o-phobics ;-) Its really remarkable to an old fart like me that when I saw Hendrix and alot of famous guitar players in the late 60's early 70's nobody gave a crap about hum. Scott Henderson who I know from doing a bunch of his album graphics wrote me a full paragraph about how he can't have hum problems dealing with various venues etc. but you know when you crank the amps and the drums are going you can't hear that stuff anyway ;-) He loved the Suhr dummy coil system and I think he still uss it. Anyway, if you want to sell these get a really good jazz fusion guy to demo them on YouTube.
Mike I've always said those frequency plots are of minimal value, I got the Syscomp and used it a bunch on my last primo PAF product development, just out of curiosity to see where the peaks were falling from different things I was doing. It was fun and that device is a great piece of gear, but at the end of it all I put it away and did ear listening only and chose one recipe that had a slighlty lower rez peak. There's so much more going on that just what rez peak is doing, thats why I said most humbuckers look alike on the chart because you don't see much detail in the mids or harmonics that might be higher than the rez peak, there are some things you just can't measure with gear and can only define by playing for a couple of weeks and doing alot of exhausting A/B/C substitution tests etc. I think the Zexcoil pickups are a great design, well thought out and possibly could be a good market for them. My original designs are all low tech and I strive to stay with the higher magnet wire gauges for reasons stated. Dave, didn't you once say that Bill Lawrence uses electrical steel poles for his stuff, it would make sense to do that because that stuff does make sweet treble tones, been there done that in my PAF journey, in buckers its too darkish, plus that stuff is really expensive. There are some small foundries that make it and might be worth messing with. I still have a bunch of 3/16" rod stock I had center ground from 1/4" electrical steel rod, it may come in useful at some point so I hang onto it.

[David Schwab]

Dave, I have customers that come to me that play classic rock, R&B and blues, and they all use some kind of hum canceling pickups in their Fenders. The vast majority of them use dual rail pickups from either Duncan or DiMarzio. I have a box full of Fender single coils from doing these mods. These guys don't even want them.

I think in the late 60s people might have cared about hum, but what choice did you have? Clearly it was a concern since both Gibson and Leo developed hum canceling pickups, and Leo made the Jazz bass and P bass hum canceling. He switched the P from a single coil to a humbucker.

As far as we know, Hendrix might have used EMGs if he was still alive! Hendrix also used those coiled cords to roll off some high end.

These days a lot of players just want a good tone.

[Possum]

Guess it depends where you live. Portland is a center for west coast blues and blues is everywhere here any night of the week. We have a huge blues festival every year with headliners who's names any blues guy would know. I've attended blues jams there for about 8 years and only hum canceling strat pickups I ever saw were a set of Kinmans. And actually they were the best noiseless strat pickups I ever heard and was surprised that they were. Still I've made strat sets for Kinman owners who got tired of the lack of single coil sparkle they have. Portland maybe isn't typical and is kind of old school territory, the most desired amps are old Fenders, the majority of the boutique amps that have showed up just don't have the same great tones the old stuff does. Pedal users are near non-existant at the jams unless you go to one where the rock guys hang out too, godawful tones and volume levels that drive you out the door. The blues guys that do use pedals only use real transparent ones for a mild boost at low volume gigs. If I bought a new Fender guitar I'd yank the pickups out too, the stuff they are making these days is abysmally mediocre. I think Fender's pickups went downhill in the early 80's and never recovered what they had, but its good for our businesses if we took the time to learn how to bring those tones back. Hendrix using EMG's??? ;-) His biggest clone, SRV didn't like anything modern for the most part, though I think he had a lipstick tube pickup strat. Stevie used coil cords for the same reason. He did have a dummy coil in his guitar but only used it in high noise situations. There's one blues exception I can think of, Coco Montoya uses Lawrence blade pickups and he makes them sound fantastic, and inpspired me to buy a set in the early 90's, but I always went back to the noisy simple stuff, there's just no match for low tech classic designs for me.

[big_teee]

Guess it depends where you live. Portland is a center for west coast blues and blues is everywhere here any night of the week. We have a huge blues festival every year with headliners who's names any blues guy would know. I've attended blues jams there for about 8 years and only hum canceling strat pickups I ever saw were a set of Kinmans. And actually they were the best noiseless strat pickups I ever heard and was surprised that they were. Still I've made strat sets for Kinman owners who got tired of the lack of single coil sparkle they have. Portland maybe isn't typical and is kind of old school territory, the most desired amps are old Fenders, the majority of the boutique amps that have showed up just don't have the same great tones the old stuff does. Pedal users are near non-existant at the jams unless you go to one where the rock guys hang out too, godawful tones and volume levels that drive you out the door. The blues guys that do use pedals only use real transparent ones for a mild boost at low volume gigs. If I bought a new Fender guitar I'd yank the pickups out too, the stuff they are making these days is abysmally mediocre. I think Fender's pickups went downhill in the early 80's and never recovered what they had, but its good for our businesses if we took the time to learn how to bring those tones back. Hendrix using EMG's??? ;-) His biggest clone, SRV didn't like anything modern for the most part, though I think he had a lipstick tube pickup strat. Stevie used coil cords for the same reason. He did have a dummy coil in his guitar but only used it in high noise situations. There's one blues exception I can think of, Coco Montoya uses Lawrence blade pickups and he makes them sound fantastic, and inpspired me to buy a set in the early 90's, but I always went back to the noisy simple stuff, there's just no match for low tech classic designs for me.

I'm with you on the vintage stuff.
In my area, I've sold several strat sets, to replace the fender noiseless pickups.
Just don't have that vintage tone everyone wants.
They always want the 60s and 70s low wind strat sets.
Grey bottoms rule in my area.
The Modern Amp that is real popular here is the Fender HotRod Deville with the 4x10 Speakers.
A real good amp for the Price.
The Twin reverb is revered, but out of reach of a lot of the local players price wise.
Different folks like different stuff, Vintage Rules Here in My area.
Terry

[David Schwab]

Guess it depends where you live. Portland is a center for west coast blues and blues is everywhere here any night of the week.

Well I'm close to NYC, which is the center of the Universe. Theres every kind of music here. Playing blues every day would be like eating pasta every day. I mean it's basically the same no matter how you play it. I'm a very good blues guitarist, but I find it limiting. I'm also Italian so I've eaten a lot of pasta over the years. Its nice to try new things.

I think Fender's pickups went downhill in the early 80's and never recovered what they had

Well that's when they bought the company from CBS, and had no factories and were putting guitars together from left over parts. Of course the company we call Fender now is only in name. Same with Gibson.

I was just doing a setup on a Chinese Squire Strat. It had the ceramic pickups and 500k pots. It was actually a very nice guitar, but rather shrill sounding. How hard would it have been to stick 250k pots in the guitar to warm up the pickups? That clearly shows a "I don't give a crap and use any parts" attitude about the guitars.

So neither of these companies should be held up in high regards IMO. They are money making machines, not instrument makers.

Hendrix using EMG's??? ;-) His biggest clone, SRV didn't like anything modern for the most part, though I think he had a lipstick tube pickup strat.

Of course he would have. He was trying to find new tones and make his guitar sound like something else. Hendrix wasn't vintage one little bit! Hendrix was modern for his time. SRV can imitate Hendrix, but SRV never did anything innovative like Hendrix did. Don't get me wrong, I like SRV, but he's a blues player. Jimi changed the way people play guitar, and did new things with it. Jimi was using all kinds of effects no one else had and would try anything to get new tones.

It's easy to say if there wasn't a Hendrix there wouldn't have been a SRV. Your view of the world is to do nothing new and keep regurgitating the past. It's easy to play the blues when its all been done already. Just imitate every note you have heard so far. No one is expecting anything new.

[Possum]

You'd get yer ass chewed off here and in Austin, lol ;-) You may think you know the blues. The reason I like Portland is its one the remaining places where west coast blues is still played, there's a whole seperate blues guitar language for that stuff that came straight from Charlie Christian and others. Its sometimes called jump blues or swing and its not easy to play. Its more reminiscent of when blues guitar and jazz were still real close to each other. I had to learn how to play over II-V changes when I moved to Portland and get beyond the mindless boring pentatonic junk everyone plays badly, but finding this stuff was exactly what I needed as I was really bored with pentatonic simpliicities. Think Charlie Baty, Junior Watson, Duke Robillard, if you can stand on the same stage as those guys and not get yer head cut off I'd be surprised ;-) You wouldn't catch me trying that ;-)

The first time I saw SRV was in Los Angeles and they booed him for being another Hendrix clone. It was all he played that night and they hated it, pretty sad because his first album had come out and he didn't have the confidence to play his own stuff, so flopped badly.

I hear alot of guys tell me oh blues is easy and boring to play its too simple blah blah. and I used to think that when I was younger. Now I realize that to play it as good as the originators of the music is incredibly difficult. Take a look at Albert Collins, that guy could play one note and have a whole crowd on its feet jumping for joy. Hubert Sumlin, Clapton and others have tried to pull off his simple licks and they never have the same soul or feel. Freddie King, holy crap, look at the ton of great songs he wrote, what a fiery guitar. Those guys invented electric blues, people try to copy it but guys like Joe Bonamassa will be long forgotten compared to Freddie, Buddy Guy, Muddy Waters, Lonnie Johnson, Robert Johnson.

[ScottA]

Man, you guys love to take a thread on a walkabout!

Thanks again for the kind words and support. It certainly isn't easy to get a lot of guitar players to use something new. I think people in general do want less noise, but they've become conditioned to believe that "noiseless" has to be a compromise. I've gotten some really great feedback so far though, some pretty discerning users saying these are the best noiseless pickups they've heard (and the frequency analysis supports that the response is closer to a true single coil), so I'm encouraged although I realize it'll be an uphill battle.