Would you kindly clarify this as it applies to the increase of "white" noise when the volume pot is backed off from 10?It is fatiguing to observe how this debate is running in eternal circles - driven by the members who do not grip the difference between DC-resistance and impedance at resonance, voltage noise vs current noise etc.
THAT Corp. makes BJT arrays. InterFET makes dual matched JFETs in the TO-78 package.
Probably better to get a bag of low noise types then mount on a strip board.10k gridstopper with the appropriate added G-k capacitance solves that problem. I recall that it's not a good idea to eliminate the gridstopper altogether, especially with a unexpected input levels.[pot noise source]...usually followed by the grid stopper or gate stopper resistor between the pickup and preamp. We talked about this early in this thread, but it was subsequently forgotten in the midst of all the subsequent arguments about the merits or otherwise of a 1 dB noise improvement.
DIY guitar amp builds sometimes entirely leave out this resistor, but I have heard an AM radio station come through a DIY guitar amp. Completely omitting an input RF filter of some sort is not a great idea!
For those concerned with every last decibel of noise, perhaps some experiments with Ferrite beads and/or a small inductor might be in order.
-Gnobuddy
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I'll try. In case your pot is wired as a voltage divider between P.U. and and amp input, reducing from "10" increases series resistance of your source to a certain amount. With a JFET input I would not expect much difference, but with a BJT with its input noise current this will be audible. I should mention that for this reason the well respected NE5532 (BJT input) is a bad choice for guitar PU input producing much more noise than the TL072 (JFET input).
A simple LTSpice simulation illustrates impedance vs frequency of a typical magnetic pickup. Note that in the region of resonant frequency around 5 kHz there is an impedance peak limited mostly by the value of the potentiometer.
That is the region where we hear the "white" noise.
That is the region where we hear the "white" noise.
Attachments
Somehow, somewhere, I suspected noise current might have played a part, but I could not see any if the pickups had no output. Then I wondered if whatever voltage leaks out of the FET gate causes enough current in the circuit that would increase noise. I guess this would be more true with a BJT base current, but again with no voltage being generated from the pickups, I could not see.
So the noise source of interest is caused by the room temperature molecular activity in the volume pot. The "silent" active pickups reduce the length of the winding AND decrease the value of the pot by 20 times.
Here is a good article on guitar pickups and resonant peaks. Incidentally, I fail to see how a resonant peak may be obtained at 0 Hz..
Know Your Tools: Interpreting Electric Guitar Pickup Specs, Part I - GuitarPlayer.com
Humbucker 25k Buffered Volume Pot
My buffer idea has already been discovered. It's only matter of buffering the pickups at the selector switch output. The volume pot value is decreased to 25k.
The Guitar Wiring Blog - diagrams and tips: active
My buffer idea has already been discovered. It's only matter of buffering the pickups at the selector switch output. The volume pot value is decreased to 25k.
The Guitar Wiring Blog - diagrams and tips: active
Yes, it does. It also brings the total DC resistance between guitar and preamp up to 14k - 30k not to mention the even bigger impedance around the pickup resonance. And this is with the guitar volume pot at maximum - the best-case scenario!
With the source resistance up in the 14k - 30k region (higher at 3 - 4 kHz), this brings the thermal noise from the guitar up to realistic levels, i.e. much more than a 4k resistor with no volume pot.
And with this increased (and realistic) amount of thermal noise, the TL072 has a noise figure of a couple of dB, and as a result, you cannot do significantly better, noise-wise, than a TL072...
We discussed this (noise performance of OPA-thingy and TL0-thingy with a 20k guitar source resistance) many, many, posts ago, complete with graphs and math.
Looking back, the origins of Heavy Metal goes back to what, 1968? (Black Sabbath / Deep Purple.) That was fifty years ago. You can be sure that a lot of smart people have had a go at quieting guitar electronics hiss since then.
And yet, half a century later, there aren't a whole lot of (hiss-reduction) changes to point to. Nowadays I see JFETs at the input of high-gain tube amps (change #1). Active pickups (change #2) have been introduced a dozen times by a dozen companies, but today EMGs hang on by a thread, and most of the rest have been forgotten. Grid stoppers / gate stoppers have been reduced from 68k and 33k down to 10k (change #3). And now you can go online and choose from a variety of noise-gates in brightly painted aluminium boxes (change #4).
What else? Hall-effect pickups have been tried, and they failed dismally. Optical pickups have been tried, and they failed dismally. Piezoelectric pickups have been tried, and they work well, but they sound different, and have ended up taking over the acoustic-electric branch of guitardom, not the electric-guitar branch.
It's fascinating. Electric guitar pickups are fundamentally flawed in many ways, but there have been very few changes since the earliest electrified guitars of the late 1920s (ninety-odd years ago now.) Electro-Voice was using a humbucking coil in 1934; Seth Lover built one into his pickup design in the mid 1950s; and there really haven't been any noteworthy changes in electric guitar pickup design that have survived the test of time since then.
PRR was right, as he usually is - hiss simply hasn't been a thorn in the side for most guitarists, and nobody has really mounted a successful campaign to eradicate it, because it isn't a problem for most.
And now for some tips on what really matters when it comes to exceptional guitar playing, from the legendary session guitarist who's so good that he's been busy working in studios since the 1960s, and who is still working today, fifty-plus years later: YouTube
-Gnobuddy
I'm not part of "most guitarists". In fact, I don't feel like one at all. I don't care to play at all while I got that hiss coming out. All my subjective perceptions occur in a quiet room with my head 3 feet from the amp which is on a table. I will install the buffer and the 25k and end it there. I already have a couple of TL071s originally purchased for the MT-2. A $15 upgrade; less than what I wasted on the plastic pot.....
Here is an Excel program for calculating resonant frequencies. I don't know if it's worth it, unless you want to go bonkers. I noticed always a deadness with my B string, regardless of position or with any guitar. I think that's my ears, but only guessing without scientific testing. The fuzz box minimizes this!
GuitarFreak - guitar frequency response calculator | GuitarNutz 2
I did review the Tim Pierce's video. I was quite shocked as to how many recorded songs we hear were done by pros like him in the studio. The front-men/women learn how to play the parts for live shows.
I researched Last Train to Clarksville and found it was Louie Shelton that did it. Notice the subtle but meaningful difference when inversions are utilized!
YouTube
I don't mean to dismiss your situation - if hiss bothers you, it bothers you. Unfortunately you're in a small minority, so it makes it harder to find preexisting solutions to your problem.
I too have some things that are problematic for me, but for only a small minority of other people. Like finding electric guitars with fretboards wide enough for my fingers, or a vehicle from which I can see traffic-lights without having to duck my head several inches.
Back to your hiss issue. I wonder if you might be able to take advantage of an acoustic (rather than electronic) solution, such as some sort of simple "beam blocker"? Perhaps a vertical strip of cardboard mounted in front of the centre of the speaker, angled at 45 degrees to deflect the hissy treble to one side? I think this will have very little effect on the guitar tone itself, but it might reduce the amount of annoying high-frequency hiss.
There is also the possibility of low-passing the speaker-level signal to your guitar speaker. If you're using a solid-state amp with a low output impedance, a small series inductor in one speaker lead will do the trick. I suggest trying values between about 220uH and 100uH.
If you're using a tube amp (with a high output impedance), a series inductor won't work, but a parallel cap might - thought it might require a series resistor to keep the amp from becoming unstable. Altogether a more complex can of worms.
Oh, that @#%**^! B string! It's given me grief for some 35 years now, because I can never get it to sound in tune, on any guitar I've ever played.
Somewhere in the last ten years I bought and read this book: How Equal Temperament Ruined Harmony (and Why You Should Care) - Kindle edition by Ross W. Duffin. Arts & Photography Kindle eBooks @ Amazon.com.
And that's when I found out why tuning the guitar B-string is such a persistent problem. The open B string is tuned a major third above the G string. On a guitar, it's the only string tuned a third above another string (all the other strings are tuned a perfect fourth apart, not a major third.)
And, it turns out, in equal temperament (which the guitar uses), the major third is a terribly compromised interval. It's about fourteen cents too wide, and as a result, sounds rough and nasty.
If you tune your guitar using an accurate digital tuner and play both open G and B strings together, they sound rough and out of tune. Flatten the B string slightly (by 14 cents), and you'll hear a huge improvement in tone, as you go from the compromised equal-temperament interval to the perfect 5:4 frequency ratio of "just tuning".
Unfortunately, if you do this, now your B string and high E string will sound absolutely nasty if played together.
So you flatten the high E by 14 cents as well, and now the G, B, and high E sound great together. BUT - the high E now clashes horribly with the 2nd-fret E on the D string, and with the low E on the 6th string.
As far as I know, there's no way out of the dilemma, unless you restrict yourself to only three or four chords in one or two keys. If you want to be able to play in lots of keys and use most of the diatonic triads in each key, you are forced to go back to tuning in equal temperament. And that @#!%**& B-string will sound awful again, because major thirds in equal temperament stink.
Some years after making this aggravating discovery, I met a skilled violinist and violin teacher, and we got to talking music. I told him this whole story about the nasty-sounding guitar B string, and how that had been bugging me almost from the first day I tried to tune a guitar by ear, and how I'd just read this book that let me figure out why this was a problem.
It turned out he knew all about nasty-sounding major thirds in equal temperament. His instrument has no frets, so he isn't forced to play out-of-tune major thirds, as we guitarists are! He can play perfectly-in-tune major thirds in any key, by shifting his fingertips a hair this way or that, as required. He told me the secret is "Play sharp notes a little flat, and flat notes a little sharp". Which means, the note A# and the note Gb are not the same note to him - he plays all A#s a few cents flatter than all Gbs.
We guitarists have no choice, as there's a metal fret deciding exactly where A# is, and it is also where we have to play our Gb. Result, both our A# and our Gb are slightly out of tune...the equal temperament compromise.
I think this shows you have good ears, actually.
The problem you've been hearing is real, and it's built into the equal temperament system of music, and those of us who play fretted instruments or keyboards have no escape.I was shocked when I discovered that, too. If you have Netflix, you might like "The Wrecking Crew", a documentary film about several of the top-notch studio musicans who played on the vast majority of radio hits we grew up listening to.
Or play air-guitar over pre-recorded backing tracks. Remember Milli Vanilli?
Arrgh! A "senior moment" on my part. Sorry about my mistake.
This is something I've been trying to teach myself in the last year or two. I just recently put together a version of "Hallelujah" where my rhythm-guitar-playing friends play open-string cowboy chords down near the guitar nut, while I finger-pick a melodic part with a capo on the 5th fret, using different inversions of the same chords.
It sounds great when we manage to pull it off.
-Gnobuddy
I was jamming one day with another electric player with a strat, while I had a Guild S300-D (awesome axe). We were just doing blues chords, but I tried playing the same chords in a higher position. It sounded good. I believe the Stones do this all the time, not to mention alternative tunings. I know in large orchestras this is mandatory. The arranger dictates in what position each string player plays the piece.....This is something I've been trying to teach myself in the last year or two. I just recently put together a version of "Hallelujah" where my rhythm-guitar-playing friends play open-string cowboy chords down near the guitar nut, while I finger-pick a melodic part with a capo on the 5th fret, using different inversions of the same chords.
It sounds great when we manage to pull it off.
-Gnobuddy
One instance when we changed from one chord to the other, there was some freaky acoustic event; high pitched and sweet sounding, and perfectly in time. Never found out what it was and it never happened again. It occurred during a slide to the next chord, his and mine, probably in opposing directions. We were using significant distortion which yielded string scrape. The small room may have had something to do with it, too.
Just realized I had another brain-slip; I used A# and Gb in my last post, where I meant exactly the opposite: G# and Ab, which are the same note in equal temperament, but are not the same note to a skilled violinist.
So the three guitarists would get together and work out how to "stay out of each other's way", as one of the others put it. One would play high on the guitar neck, another low, the third might only play short chord stabs and no sustained notes.
I thought it was amazing how good the surviving Funk Brothers still sounded in the documentary film, decades after their big studio hits. Joan Osborne's cover of "What Becomes Of The Broken Hearted" with them raised the hair on my arms. It's on You Tube now, albeit with lousy sound quality: YouTube
-Gnobuddy
Cool! In the book "Standing In The Shadows of Motown" (and in the documentary film by the same name), the surviving Funk Brothers talk a little about this. They had three guitarists on most of those 1960s Motown hits, and, at first, no arranger.
So the three guitarists would get together and work out how to "stay out of each other's way", as one of the others put it. One would play high on the guitar neck, another low, the third might only play short chord stabs and no sustained notes.
I thought it was amazing how good the surviving Funk Brothers still sounded in the documentary film, decades after their big studio hits. Joan Osborne's cover of "What Becomes Of The Broken Hearted" with them raised the hair on my arms. It's on You Tube now, albeit with lousy sound quality: YouTube
Arrgh!
-Gnobuddy
Agreed. The resonant frequency is inversely proportional to the square root of inductance x capacitance; that means you cannot get a 0 Hz resonance unless you have either infinite inductance, or infinite capacitance. Neither of which are possible!
I couldn't make myself read all the way through that long meandering pair of articles, which seem riddled with confusion where there isn't any reason for it. The way all these pickups work is very simple: the vibrating string varies the reluctance of the magnetic circuit; combined with the permanent magnet, that causes a change in the magnetic flux through the coil; and Maxwell's equations predict the coil will then develop a voltage proportional to the rate of change of magnetic flux. That's it.
Everything else is merely detail. One coil or two, or six, like Roland's Hex pickups; magnetized pole-pieces or plain steel ones; none of it matters in any significant way. All that long lingering discussion about whether or not you actually need a magnet of any kind is pretty much nonsense (if there were truly zero magnetic field, you'd get zero output; there is always the earth's magnetism, and weak permanent magnetism in the guitar strings to produce some output, but it will be uselessly low.)
Those two articles also omitted a couple of things that are much more important than the guff about not needing magnets. One, the magnetic flux varies with string position in a very non-linear way, so the signal from the guitar pickup is heavily distorted. Two, the magnetic flux varies significantly only when the string vibrates towards and away from the guitar top (let's call that the "y" direction), and not when it vibrates from side to side, parallel to the guitar top (the "x" direction.)
Therefore, the pickup only responds to the string moving in the "y" direction. We are taught implicitly that when we pluck or pick a note, we should move the string sideways - parallel to the guitar top - with our pick or fingers, but this is actually the direction in which the pickup doe NOT respond! What matters is the string vibrating in the other direction, towards and away from the guitar top.
Fortunately for us, the string tends to whip around in loops and figure-eights, so whichever way you pick, there is still vertical motion (in the "y" direction) that the pickup can sense.
-Gnobuddy
I did know the string moves in a three dimensional space. I observed that when trying to find why my cheapie is still buzzing even when the height is raised. Lousy guitar but perfect for my needs of amp testing and luthier learning.
Speaking that pesky G string in standard tuning. It wasn't the B as I had mentioned (brain lock). The G has always sounded dull whether open or at any fret, on most guitars I have played. I saw a good intro lesson on GADGAD which looks interesting and may help: YouTube
I have no explanation for that. Both wound and unwound third strings sound dull to you?
Wow, McManus is a heck of a guitarist!
I've spent decades learning major scales all over the neck, and have built their use into my playing style. All of that goes out of the window as soon as the guitar is put in an alternate tuning, so I try strenuously to avoid doing that.
Instead, when I find a song I want to learn that was originally done with an alternate tuning, I usually just try and to find a way to play the signature lick or riff in standard tuning.
Two recent examples: Some weeks ago I found a way to play Howie Day's "Collide", including the descending bass line and the chord arpeggios in the bridge, with my guitar in standard tuning. (Day used a weird alternate tuning.)
More recently, in the last couple of weeks, I've rearranged Neil Young's "Harvest Moon" so I can play the signature lick, with my guitar in standard tuning (Young used another weird alternate tuning.) The song includes some picked harmonics played on a slide guitar tuned to a major chord - I can't play them as harmonics, but found I can play the same notes with a barre across the neck at the 9th fret (an E major 6th chord).
Best of all, I've been able to change the key at the same time, to suit my vocal range. I don't want to have to emit high-pitched squeals through my nose as Young himself did! (And if I feel the need, I can play it in Young's key with a capo - and still in standard tuning.)
I've never found a way to play Coldplay's "Yellow" in standard tuning, though. There's no way to duplicate the sound of those weird chords in the equally weird alternate tuning they used.
-Gnobuddy
The wounds sound much better on acoustics, but I would never use them on an electric. I somewhat recall the G sounded decent with my Guild which had an ebony neck and the right selection of wood(s).
I was able to get the action so low with no buzzing anywhere, there was no way to bend notes. It played great bar chords all the way up to the 24th fret, though. When I traded it in (a foolish decision), a guy that worked there bought it before any customer even saw it. I paid $400 new in 1979, branded hard case $100. Even had a sub-miniature phase switch; however, it was rendered useless under the fuzz.
You are enslaved to standard tuning patterns. I will mess with the DADGAD and go back if "necessary".
That is my experience as well. I often have to tune down the g-string a bit to make it sound acceptable in simple A, G or D-chords.
That sounds like an intonation problem. Come to think of it, the D string has never been all that punchy. So the D and the G are at the center of the neck, hmmm.
Some pickups have adjustable pole pieces to adjust output of individual strings. There's also the compensated nut. However, that necessarily messes with the tuning in the first position, since it increases the distance from the nut to those first few frets drastically. Going up the neck it supposedly "corrects" intonation "problems". The one I have lengthens the GBE high strings in standard tuning. I had to reverse the bridge blocks on those strings to lengthen the other end so they be intonated. I had run out of room....
The guitar sounds generally better with this nut, but the G still sounds lifeless and I too have open position problems. I find myself doing the same thing as you with tweaking the tuning of certain strings with certain chords. The only thing good about this cheapie is that if it's stolen or falls from a third story window, the event actually might make me happy.
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