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Topic: Ohms for a sweet sound? |
Karlis Abolins
From:
(near) Seattle, WA, USA
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Posted 11 Jun 2004 10:00 am |
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I have started a new project pedal steel guitar which I want to sound more like a lap steel with a sweet mellow sound. I am committed to a 11/32" string spacing due to using a stock changer. I am pretty sure that I want a humbucking pickup for low noise. In doing research about pickups, I have come to the conclusion that I want a stacked humbucker without a magnet in the lower coil.
My question to all of you knowledgeable gentlemen and ladies is: What DC resistance (ohms) would give me the type of sound I want. 17k (single coil) 20K (humbucker) has too much punch/output. Given that a guitar single coil runs about 6K and a guitar humbucker runs about 9k, would I be safe in starting out in that area, perhaps a little higher at 10K-12k?
I will probably have to settle for alnico V magnets but would prefer alnico II.
Has anyone tried this approach and what are the pitfalls?
Karlis
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Karlis Abolins
"That was then" "This is now"
 
Remington SD12 Extended E9 - Same seat, different basement
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William Peters
From:
Effort, Pennsylvania, USA
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Posted 11 Jun 2004 12:03 pm
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Karlis,
A 12 string pickup would have almost twice as much wire as a 6 string pickup would with the same number of turns. The same number of turns should result in the same amount of output voltage, but the dc resistance would be almost twice as high. If it were me, I would go for the 17k ohms. Its much easier to lower the output voltage with a resistive pad than it is to amplify it if its too low.
Also, what advantage is there to a stacked humbucker? The disadvantage is that the lower coil will be producing no useful signal at all, thus decreasing the signal to noise ratio. Basically, you would have a choke (inductance) in series with your main coil which would attenuate the higher harmonics.
A standard humbucker design produces usable (musical) signal from both coils giving you more output at a lower total impedance.
Bill
www.wgpeters.com
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Karlis Abolins
From:
(near) Seattle, WA, USA
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Posted 11 Jun 2004 1:18 pm
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Bill, Thank you for the interesting observations. A couple of questions:
Do you equate output with number of turns?
What effect besides increased resistance is there in having longer coils as on a 12 string?
17k to my ears produces too much of a strident/punchy sound. It may cut thru a mix and make the steel stand out but that is not the sound I am looking for. I am looking for a sweet mellow sound.
As far as the stacked humbucker without a magnet in the lower coil, it produces more of single coil sound without the single coil hum. It very likely also produces less output.
My goal is to have a sweet mellow sound that can go into a tube amp without any electronics in between.
Karlis |
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Chris Lucker
From:
Los Angeles, California USA
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Posted 11 Jun 2004 1:48 pm
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I would suggest you hook up with Jason Lollar. He is over on Vashon.
Chris Lucker |
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William Peters
From:
Effort, Pennsylvania, USA
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Posted 11 Jun 2004 3:27 pm
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Karlis,
Think of a guitar pickup as half of a transformer. In a regular transformer, the input winding creates a varying magnetic field, and the output of the transformer is determined by the ratio of the turns in the output windings to the turns in the input winding. In a pickup, the varying magnetic field is provided by the steel strings vibrating in the magnetic field from the permanent magnets, and 'jiggling' this field. So yes, all other factors being equal, the output voltage is determined by the number of turns.
The other factor here is inductance, and that also is determined by the number of turns, not by the dc ohmic resistance.
Now, the combination of dc resistance, the input resistance of the amplifier, the resistance of the volume pedal pot, and the pickup inductance creates another effect called Q, which determines the effective bandwidth of the pickup. This affects tone or the frequency response of the pickup.
However, even knowing all those parameters, I couldn't tell in advance what it will sound like.
The real message is that this is a whole lot more complicated than just cd ohms would imply.
The problem for me is that sound is so extremely difficult to describe in words. So when you say you want a 'sweet' sound, it has no objective meaning to me.
I think you will have to experiment, but remember that harmonic frequencies removed by the bucking coil cannot be recreated, whereas extra harmonics from the pickup can be filtered by judicious equalization.
I hated the sound of my steel until I bought a decent preamp (tubefex) with the needed eq capabilities to shape the signal to my liking.
Bill
www.wgpeters.com
edited to correct spelling
[This message was edited by William Peters on 11 June 2004 at 04:31 PM.] |
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C Dixon
From:
Duluth, GA USA
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Posted 11 Jun 2004 5:04 pm
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Well said William.
All else being equal the DC resistance measurement of a PU is a "relative" indication for comparison purposes between the same type PU's and usually from the same manufacturer only.
IE, an 18.5K "George L" PU will probably not sound ANYthing like an 18.5K PU by "Bill Lawrence", etc.
However, if you change a single thing amongst the following parmameters, the DC resistance has little if any meaning:
1. The number of turns of wire.
2. The gauge of wire (even with the DC resistance being the same).
3. The tightness of those turns to each other.
4. Whether those coils have an air core or solid core. (Called dialectric)
5. The size of the coils.
6. The distributed capacity between the coils.
7. The shape of the device the coil is wrapped around.
8. The inductance.
9. The entire magnetic properties.
10. The hysterisis and eddy current characteristics of that coil.
Finally, the resistance within, and beyond the PU does affect the "Q" of the coil, however it has no affect on its frequency response (fidelity). At audio frequencies anyway.
The best way to think of it, IF you take a given length of PU wire and stretch it out in a dead straight line, it has NO
Inductance (at audio frequencies)
capacitance (" " " " " " )
Induced voltage (and current) capabilities
Impedance
YET: its resistance remains the SAME if you wind that given piece of wire into a PU!
Strange and hard to believe for the non AC electronically trained mind, but nevertheless, very true. One of the most difficult learning curves in my years of teaching students in Electronics at RCA was the introduction of basic and advanced AC theory.
Many of them took to DC theory like a duck takes to water. But when it came to AC theory, sadly many of them simply could not aborb it. Add to that the fact that no human has EVER seen an electron or an atom or current or inductance, etc, etc and it really took some study and open mindedness along with a great deal of blind faith to learn it.
Praise Jesus for the gift of logic and learning,
carl
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Karlis Abolins
From:
(near) Seattle, WA, USA
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Posted 11 Jun 2004 6:42 pm
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Thank you Bill and Carl for taking the time to try to explain this to me. I guess I really don't need to know the details. I just want to get this kind of a sound: http://home.comcast.net/~k.abolins/sample.mp3
Any ideas? The instrument is listed as Kona Hawaiian Guitar.
Karlis |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 15 Jun 2004 4:07 pm
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Karlis, the sample you gave does indeed sound like a Kona-type (acoustic) steel guitar. To get that sound from a pedal steel, you're going to have to change a lot more than a pickup! Yes, a high impedance pickup (maybe a 22K single coil?) might help, but you're also going to have to use a small glass or plastic bar (to help provide the mellowness and lack of sustain), a lower tuning than the standard E9th, and the proper technique (playing nearer the harmonic center of the strings). Now, do all this through a good mellow amp, and I think you'll get pretty close.
However...making a heavy, solid-body guitar sound exactly like a lightweight acoustic guitar is nearly impossible. So, if you want a true "acoustic sound", make your design more like a Pedabro sans-resonator than a traditional pedal steel.
Good luck! |
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Karlis Abolins
From:
(near) Seattle, WA, USA
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Posted 16 Jun 2004 7:35 am
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Donny, Thanks for the insightful comments about the sound clip. My project guitar will have more natural resonance in the body than most traditional steel guitars so I am looking for a pickup that can blend the subtle overtones produced by the body into the sound. I "think" that I need a pickup that has less output with more compression like the sounds associated with older pickups that used Alnico II magnets.
The sound clip has two obvious components. I certainly can't get that acoustic component of the sound without a similar guitar. What I am after is the electric sound. That seems to be unique as well.
Karlis |
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Ray Minich
From:
Bradford, Pa. Frozen Tundra
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Posted 16 Jun 2004 3:36 pm
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Question Carl... does the string material make much difference from a practical point of view? To optimize the signal generating effect, would the pickup distance from the string need to be adjusted if you change from nickel to stainless for example?
As a side note, I've often wondered if we shouldn't learn AC electronics before DC, 'cause if you try to use what you've learned in DC to understand Z, it gets real deep in a hurry  Now for the 28 ways to mathematically depict a time varying signal....
Also, in my years of playing with electrons there are two things that I've found to have as much art as there is science in their design methods... Transformers, and antennas. [This message was edited by Ray Minich on 16 June 2004 at 04:43 PM.] |
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John Billings
From:
Ohio, USA
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Posted 17 Jun 2004 6:16 am
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Is that Lindley in the audio clip? Sounds like "To Know Him Is To Love Hiim" What about a piezo bridge? One of my sliders is an old National archtop. 51 New Yorker. Jason rewound the pup. I had my luthier put on a Fishman piezo bridge for archtop guitars. I used a stereo jack, and can send the piezo pup to a separate amp. It sounds very acoustic with my Acoustic D. I.. Seems to me that may be more of the sound you're lookin' for.
JB |
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John Billings
From:
Ohio, USA
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Posted 17 Jun 2004 6:37 am
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| Took a shower and thought about it. I see no reason that the fingers couldn't be machined to accept transducers. I know that there are people using benders on their acoustic/eulectric guitars with no apparent extraneous noises. Corse it'd be a crapshoot as to how it sounded. Don't really know until it's tried. |
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C Dixon
From:
Duluth, GA USA
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Posted 17 Jun 2004 7:11 am
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| Quote: |
| "Question Carl... does the string material make much difference from a practical point of view? To optimize the signal generating effect, would the pickup distance from the string need to be adjusted if you change from nickel to stainless for example?" |
Ray,
I don't know. I imagine Rick Aiello would know.
| Quote: |
| "As a side note, I've often wondered if we shouldn't learn AC electronics before DC, 'cause if you try to use what you've learned in DC to understand Z, it gets real deep in a hurry Now for the 28 ways to mathematically depict a time varying signal...." |
I feel that if electronic schools tried to teach AC theory before DC theory, probably more would drop out than the other way around. Because AC builds on DC theory. Not the other way around.
What I discovered in over 40 yrs of instruction was; MOST students are NOT logical thinkers. Worse, most cannot absorb easily (if at all) UNLESS they can see it happening. This is why they have such great difficulty with electronic theory, especially AC theory.
Thus, it is much easier to teach mechanical things than electrical/electronic things. Because in electronics, one cannot "see" most of what is happening.
We can see the effects with equipment, but the non logical mind is distrusting of ANY thing they cannot see directly with their own eyes. So an oscilloscope picture of a signal means absolutely nothing to the non logical mind. IN other words, "you are just trying to prove a point with that piece of equipment!" Which has been said a time or two.
This is why I feel we need to return in schools to teaching those subjects that teach logic. To many, sadly even adults, things are a result of magic or coincidence, rather than a fact based phenomenon.
Spiritual things, such as God being 3 persons in one, excepted of course. This is because God is NOT limited by the logic he gave man to live by on earth, nor man's timeclock. Only when we are in heaven will we no longer be bound by logic and time. It is this that true faith is built upon. Praise his holy name.
carl |
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Rick Aiello
From:
Berryville, VA USA
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Posted 17 Jun 2004 8:26 am
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Plain (carbon) steel is used for "plain" strings and as the core of wound strings because it is both ferromagnetic and ductile.
Nickel is ferromagnetic ...
Some Nickel wound strings are said to have "Pure Nickel" windings. It isn't really "pure" (some nickel alloy) but that's what they call it.
Nickel plated steel ... commonly known as NPS .... is a steel winding with a nickel plating applied.
The windings on Stainless Steel wounds are generally Martensitic stainless (400 series) ... it is magnetic. (Unlike Austenitic stainless ... 300 series .. which is not ferromagnetic)
Although plain steel, nickel, and 400 series SS have different magnetic permeabilities ... I can't imagine that any type of fine tuning (pup height) would be needed as you go from Nickel wound to Stainless wound ... providing the same gauges are being used.
Maybe some folks with "Bat Ears" might need to tweak 
------------------
www.horseshoemagnets.com |
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Jim Palenscar
From:
Oceanside, Calif, USA
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Posted 17 Jun 2004 10:42 am
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| Remember that where you mount the pickup will also greatly determine it's tonal characteristics- ie.- you could design the perfect one with all the right calulations and then mount it too close or far from the bridge and miss the target completely~~ |
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Ray Minich
From:
Bradford, Pa. Frozen Tundra
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Posted 17 Jun 2004 2:37 pm
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Rick, thanks very much for the info. I appreciate it.
Jim, you remember what they say about the best laid plans of mice & men? Once again it comes to science assisting art, not displacing it. I can picture trying to design a Stradavarius on a CADCAM system. Probably sound like a block of concrete
Regards all...[This message was edited by Ray Minich on 17 June 2004 at 03:43 PM.] |
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Jennings Ward
From:
Edgewater, Florida, R.I.P.
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Posted 22 Jun 2004 4:33 pm
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| Hello, to achieve the tone that I like , I Use the peavy 31 band EQ.in addition to my profex and delta fex into a nashville 1000 amp . takes a little time searching at first but great sound can be achieved. Sincerly,,,,,, Jennings |
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