Use Saw Studio as a Way to Determine Resonance in a Guitar Pickup

[John Ludlow]

John,

OK!

What of this?: TCI Pickups with Paul Reed Smith | PRS Guitars

• His striking hand technique is rather "poor" compared to this: Larry Carlton - Emotions wound us so (live Last Nite album)
• Notice that Larry is using "up stokes" and he is able to obtains the sounds that he does.I would still like to know what the end result is of all of this research?

If you would be so kind and indulge me a bit here.

Even though I don't think his technique has anything to do with the topic at hand, I agree with you that Larry Carlton makes him look bad. But who doesn't Larry Carlton make look bad? I've watched a couple of videos now of him playing with his friend (and LA session musician legend) Tim Pierce. If PRS were you or me - well, anyway, if he were me there'd be no reason to combine us on the same stage for money. But PRS gets to do it, answer chops questions - and call it a workshop - because his company makes great guitars. And he's a great marketer who periodically gets to talk about aspects of his company's technology on stage that clearly his minions must know and understand - because he doesn't. And yet when he stops talking, people just nod seriously anyway. It's a good life for him.

[Cary B. Cornett]

As a recovering studio tech, I may just have something for you.

There is a thing we sometimes use to troubleshoot tape recorders called a "flux loop". We use it to test playback heads and preamps. The flux loop is a simple coil of fine magnet wire, usually just a few turns, wound on a little piece of phenolic board. There is a resistor, usually about 600 ohms, connected to one end of the coil. We feed this with a signal generator or other signal source, and loop goes up against the playback head.

The same thing could be used to induce a signal in a guitar pickup without needing to take apart the guitar and get at the wiring. With any normal line level signal, this would be completely safe. In fact the magnetic field produced is quite small (tape playback heads are very sensitive, and the preamps they feed have a lot of gain. Just put the flux loop against the face of the pickup and see what you get back.

SawStudio may not be the most convenient test signal source. I would strongly suggest you try a free program called Room EQ Wizard. Do a search and you'll find it. It both generates test signals and analyzes the results. You could run the same kind of sweep that REW does to test the response of a room, only you'd be feeding the test signal to the flux loop instead of the an amplifier and speakers, and "reading" the output of your guitar instead of a test microphone. It's free. Get it, try it. If it doesn't get you what you are after, you didn't waste a ton of money. And no, you can't damage your pickup with it.

[Dave Labrecque]

Gotta agree that the humbucker approach for getting a signal into a pickup is brilliant. It does limit you to that pickup, of course.

Nice to see that the thought of a voice coil exciting the pickup (not the other way around) may have some validity.

I definitely am not more knowledgeable than you, John. I think we're both stumbling through this on the bits and pieces of physics and electronics theory that our brains have absorbed over the decades.

[Dave Labrecque]

Very cool ideas, Cary. In fact, the fluxy thing reminded me of a thought I had, but didn't bring up to John: I have one of those eighth-inch-TS-plug-to-cassette adapters kicking around somewhere. I use(d) it to run a signal into a small/cheap boom box when I wanted a speaker for an MP3 player. Pretty much the same thing you were describing, right? Perhaps with more winds?

[mr_es335]

John,

R: Basically, it will hopefully allow one to tune one's pickups for one's application.
Q: What specifically is that application?

R: I'm not sure I can do a better job. Can you be more specific?
My R: I instruct guitar - beginning with a nylon-strung guitar and a 1mm, Delrin, Jazz Teardrop plectrum.

• The student is taught how to develop their listening skills using the acronym "D.A.T" - Duration, - Amplitude - Timbre - with a focus on Timbre at the outset.
• The student is taught how to use the plectrum in the striking - not the plucking, of the string.
• All that the student has at their immediate disposal is 1) themselves, 2) the guitar, 3) the six strings, 4) the plectrum and 5) two simple exercise to learn and to perform

The objective: To create a sound that is "pleasant" based on "timbre" and a proper understanding of the term "legato"

Over the years I have had so many beginning guitarists who wanted to learn the guitar for what I would refer to as "ulterior motives" rather than musical motives. For example, Julian Bream and Larry Carlton both inspire me in how to approach each instrument in a simpler, yet, more musical manner - regardless of the equipment used.

As a result then, it would be appreciative if you would be so kind as to answer the above question with regards to the application.

Thank you.

[John Ludlow]

Cary, I like your flux loop idea, although I worry about introducing noise into the system. At the moment, though, I don't see any other alternative. So, unless something better pops up - I'll probably try it.

It has occurred to me that my original stipulation of exciting the circuit using pink is unnecessary. My reasoning is that pickup resonance isn't harmonically produced, so there's no reason to muddle up the screen with other frequencies. Rather, it's more 'mechanical', in that any electrical signal will be sufficient to cause it to be produced. So, in fact, a better solution would be to use a relatively low frequency sine. Then, when looking at the result on a frequency analyzer, there should be the known low frequency, plus a higher one that is generated by the LC sub-circuit. Any other lesser peaks I would look at suspiciously as probable noise.

I haven't picked it up yet, but I'm curious what it is about 'Room EQ Wizard' that I'll like better than SAW for this application?

[John Ludlow]

John,

R: Basically, it will hopefully allow one to tune one's pickups for one's application.
Q: What specifically is that application?

R: I'm not sure I can do a better job. Can you be more specific?
My R: I instruct guitar - beginning with a nylon-strung guitar and a 1mm, Delrin, Jazz Teardrop plectrum.

• The student is taught how to develop their listening skills using the acronym "D.A.T" - Duration, - Amplitude - Timbre - with a focus on Timbre at the outset.
• The student is taught how to use the plectrum in the striking - not the plucking, of the string.
• All that the student has at their immediate disposal is 1) themselves, 2) the guitar, 3) the six strings, 4) the plectrum and 5) two simple exercise to learn and to perform

The objective: To create a sound that is "pleasant" based on "timbre" and a proper understanding of the term "legato"

Over the years I have had so many beginning guitarists who wanted to learn the guitar for what I would refer to as "ulterior motives" rather than musical motives. For example, Julian Bream and Larry Carlton both inspire me in how to approach each instrument in a simpler, yet, more musical manner - regardless of the equipment used.

As a result then, it would be appreciative if you would be so kind as to answer the above question with regards to the application.

Thank you.

Dell, I note that you have made a big effort to be respectful, if a tad pushy, in your requests, and I thank you for that. And I want to be respectful as well.

The thing is though that I am well aware of your minimalist leanings so far as music production is concerned. And - I know that you are well aware of mine not being minimalist. So, I presume that your re-hashing of this old contention between us is for others to benefit from your musical opinion. You are aware that I am aware that you are a music teacher. But, I am not your student, whether you are aware of it or not. And, in fact, I've been playing guitar for over fifty-five years now (which you are aware of) and am not interested in beginner's instruction from you. I'm happy that you are satisfied with your approach to music, and I wish that you could find it in your heart to be happy with my satisfaction in my approach as well. Surely there is room in this world for both.

But, if not, the bottom line is that I'm not going to play straight man for you on this issue any longer. If you feel the need to step up on to your soap box to spread the word - I'll understand (sort of...), but please just do it without requiring me to spend my time to help set it up for you at my expense, as if it happened in the course of forum conversation. Just go for it - let rip.

[mr_es335]

John,

No disrespect, but "pushy" is a subjective term. I believe you to be the very same. Interesting!

All that I would like to know from you is "What specifically is that application?" That is it!

[Dave Labrecque]

Dell,

He's learned that certain circuits (like that involving a guitar pickup) can have natural resonances based on component values in the circuit. Varying those values changes the resonances. He thought it'd be cool to leverage that bit of physics to get different sounds out of his guitar, ideally with a knob that would allow him to continuously adjust the resonances to his liking. But to design the circuit correctly (determine the range of values that would work the best for his needs), he needs to experiment with components of different values. He's been trying to determine the best way to do that.

It's taking Paul Reed Smith's idea to a new level, if successful.

Can you dig it?

[mr_es335]

Dave,

"Can you dig it?" ... simply, "Nope!"

I would just like to know "Why?" It is because it is there... or just bored! I am NOT meaning to be rude or obnoxious - I am simply curious to know why...that is all!