mushy the shroom Posted October 5, 2004 Report Share Posted October 5, 2004 I thought up this idea for a very simple pickup design to be used on any instrument with conducting strings. The layout is: The strings are suspended over a powerful magnet (I used neodymium), and all connected so that electricity can flow through all of them at once. This means that the nut and bridge have to be metal, or there has to be a metal contact behing the nut or bridge so that all the strings are in electrical contact with each other. Next, a wire connects one end of the strings with a connector on the output jack. Another wire connects the other end to the other connector on the output jack. I'm not sure how to ground this, but it isn't really necessary anyway. And that's it! It works because the conducting string vibrates though a magnetic field, which creates electricity. Now, instead of that electicity being amplified through the coil around the magnet, it gets sent through the strings and straight to the output jack. My test had a signal with about half the volume of nomal pickups. I built a headless guitar from scratch (the most machined part I bought was an output jack) to test this, and it worked very well. One thing I observed though, is that because the output is so weak, any boost (such as distortion) raises the volume level. For practical use, there would need to be some kind of booster that boosts the signal enough to be pratical, but doesn't drive it into distortion. Maybe this should be in the announcements and test area, but I'll leave it for a mod to decide. Tell me what you think! Quote Link to comment Share on other sites More sharing options...
Jon Bell Posted October 5, 2004 Report Share Posted October 5, 2004 Cool idea! I read that a guy called Dan Armstrong worked on a similar idea in the 70s but it was abandoned. How did your guitar sound? Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 5, 2004 Author Report Share Posted October 5, 2004 He may have.. Dan passed away last month. Anyway, the tone was full, but the signal weak. I would describe it as transparent, but when hooked up with a lot of ditsortion, it had a very smooth and kind of airy, or hollow sound. Very unique. Quote Link to comment Share on other sites More sharing options...
Biohazard Posted October 5, 2004 Report Share Posted October 5, 2004 Cool, that sounds good. Quote Link to comment Share on other sites More sharing options...
ansil Posted October 6, 2004 Report Share Posted October 6, 2004 interesting got any clips????? Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 6, 2004 Author Report Share Posted October 6, 2004 interesting got any clips????? Sorry, I don't. I retired the guitar after some extreme warpage in the neck (I didn't put a truss rod in). Also, the bridge needs some work, and it's nearly impossible to tune, but if I recieve some inspiration, I may get back to work on it. Quote Link to comment Share on other sites More sharing options...
Devon Headen Posted October 6, 2004 Report Share Posted October 6, 2004 Would it be a stronger signal if the magnet was closer to the strings? It seems like a powerful magnet would pull the strings towards it. I guess you have to find a happy medium of distance. Sounds like a very interesting idea, though. I might have to try it out. If you ever get the guitar back together I'd appreciate if you posted sound clips. Quote Link to comment Share on other sites More sharing options...
Kevan Posted October 6, 2004 Report Share Posted October 6, 2004 Mushy- this is the correct place for the thread. The Announcements section is really only for site announcements (and test posts). Dan Armstrong actually passed away several months ago. I got the privlege of hanging out with his son, Kent, at this past Summer NAMM. Great guy with some great stories, esp. regarding his father. "You are the circuit bridge." With the strings being conductive, isn't the player now grounding them out when they touch the strings? Also, why have each string connected to each other (circuit-wise)? Maybe you'd get a stronger signal if you split them up (singles? pairs? triplets?), and sent the corresponding signals to a single output, or even a mini-mixer inside to fine-tune which strings output more/less than the others- kinda like the old Ripley setup, but with a different type of pickup. Just thinkin' aloud...... Quote Link to comment Share on other sites More sharing options...
lovekraft Posted October 6, 2004 Report Share Posted October 6, 2004 Yes, this has been proposed many times before, as far back as the 1930s if memory serves - a quick search of patent records should tell you more about who, when, and how often. It's the guitarist's role as an alternate path to ground that has always caused me to avoid any system that deliberately applies a voltage to the strings. But that's just me, and I have a strong aversion to conducting any amount of external electric current. Quote Link to comment Share on other sites More sharing options...
psw Posted October 6, 2004 Report Share Posted October 6, 2004 I've heard of this idea from the Pickup Maker's Forum but the power was very low. Basically they described the string as acting in the role of of the coil...but with only the one winding. Compared to the thousands on a conventional pickup. Magnetic power can compensate for less windings to a degree but eventually they will inhibit the vibration of the string and certainly deflect it out of tune. I love rare earth magnets and encourage you to experiment further. I'll have a go myself. The most practical place to put the magnets is by the bridge as it's harder to deflect the strings and you can concentrate the field around the string. However the movement of the string is less here than at the 12th fret and this maybe important to the output you are getting so perhaps you'll need to play around with it. LK, the strings conduct very small amounts of inducted voltage...like on a normal pickup...But there is a risk as the strings can't really be grounded I guess. Perhaps some sort of circuit breaker to provide shock protection could be incorporated. I'm sure this would need quite a bit of preamping! How big a Magnet were you using Mushy? psw Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 6, 2004 Author Report Share Posted October 6, 2004 Yeah, I didn't think I would be the first to think of such a simple concept. But, I didn't really research it, and I havent seen it on any other guitar. Kevan, it would be very simple to split the signals, but the string to string volume was pretty good as is. Yeah, if you have a short, you're pretty much fried. Psw- My magnets were cylinders about 1 1/4" in diameter and 1/4" thick. I had two stacks of two magnets each in a "oo" pattern under the strings. These magnets are incredibly strong! I used to keep them in my pockets while going to school, and if I got close to a locker, they would latch on with a loud BANG! and swift removal yielded holes in my pants. So I ended up with 6 holes in my pants (I had lots of pockets), and an aching leg (because, believe it or not, they clotted the iron in my bloodstream), before I decided to do something useful with them! Quote Link to comment Share on other sites More sharing options...
javacody Posted October 7, 2004 Report Share Posted October 7, 2004 (edited) What if you made the guitar battery powered? Is there a way you could pass only the signal to preamp circuitry and basically buffer the string-pickup system electrically (is decouple the correct term here)? Maybe a capacitor (like on the input of an effect pedal)? Edited October 7, 2004 by javacody Quote Link to comment Share on other sites More sharing options...
lovekraft Posted October 7, 2004 Report Share Posted October 7, 2004 ...because, believe it or not, they clotted the iron in my bloodstream... Excuse me? Quote Link to comment Share on other sites More sharing options...
crafty Posted October 7, 2004 Report Share Posted October 7, 2004 Yeah, you saw X2: X-Men United, right? You know, where Magneto grabs the excess iron out of the guard's blood and uses it as projectiles to kill the same guard and escape from his acrylic prison. Rare earth magnets are powerful, but there's not enough iron in your blood to make a clot big enough to feel. If it did, you'd have bigger problems that an aching leg. But hey, I'm no physician...I just stayed at a Holiday Inn Express last night. Quote Link to comment Share on other sites More sharing options...
lovekraft Posted October 7, 2004 Report Share Posted October 7, 2004 No, seriously, if a pocketful of little rare earth magnets could cause blood clots, wouldn't a trip through a MRI tunnel at 2 Teslas (20,000 Gauss) tear you to pieces!!??! I'm not a doctor either, but I did pass biology and physics in high school, and I do know that hemoglobin is not ferromagnetic. Perhaps one of those clots has migrated quite a distance upwards. Quote Link to comment Share on other sites More sharing options...
psw Posted October 7, 2004 Report Share Posted October 7, 2004 That's some powerfull magnets there...they will definitely cause problems with the string vibrations. I use 3x2mm or 5x1.5mm in my magnet and sustainer designs as I estimate that these have a similar pull as a conventional pickup. There's all sorts of supposed health effects both detrimental and benificial of magnets (these and crystals, etc are probably better discussed on some other wacky forum). Javacody has got the idea I was trying to express Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 7, 2004 Author Report Share Posted October 7, 2004 (edited) What if you made the guitar battery powered? Is there a way you could pass only the signal to preamp circuitry and basically buffer the string-pickup system electrically (is decouple the correct term here)? Maybe a capacitor (like on the input of an effect pedal)? A Preamp with EQ and gain would be perfect for this application. As for all this stuff with the clotting, I'm not sure exactly what it did, but it made my leg ache! Call it mystic ferromagnetic waves, or not, it hurt! The power dampened the strings a little bit, but I had them about 3/8" away from the strings, and buried below some maple. The sustain was sacrificed, but not too badly. On my band's beta website, I have a menu, pictures, and info about it. Most of it is corny, because I had to write it for people who knew nothing about guitars. The site is here: http://staticline.drastic-creations.com/ne...yan/guitar.html . Edited October 7, 2004 by mushy the shroom Quote Link to comment Share on other sites More sharing options...
psw Posted October 7, 2004 Report Share Posted October 7, 2004 Ok, I see, so you just have the two magnets a fair way aways from the strings. Not one or two per string as I kinda thought! Are the magnets the same polarity by the way (eg both north poles facing the strings)? I think smaller more focused magnets for each string would improve some of the problems. Also...I don't see any reason for the nut to be wired up (the srings wire it up after all) or even be metal, as all of the strings are connected at the bridge by your brass plate. psw Quote Link to comment Share on other sites More sharing options...
javacody Posted October 7, 2004 Report Share Posted October 7, 2004 What if you ran the signal through an inductor? Is there someway to move the wire coil off of pickups? Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 7, 2004 Author Report Share Posted October 7, 2004 Ok, I see, so you just have the two magnets a fair way aways from the strings. Not one or two per string as I kinda thought! Are the magnets the same polarity by the way (eg both north poles facing the strings)? I think smaller more focused magnets for each string would improve some of the problems. Also...I don't see any reason for the nut to be wired up (the srings wire it up after all) or even be metal, as all of the strings are connected at the bridge by your brass plate. psw One is north side up, and the other is south side up. This yields the maximum magnetic field through all of the strings. I think that the nut does have to be wired up, because the circuit must include the string. If both wires came off the bridge, it may not work. I haven't tested it, but I don't think it would work. Javacody- I haven't the slightest idea! The wire coil in conventional pickups just needs to encompass the magnetic field, but I'm not sure what the advantage would be. On mine, there is no coil (well, you could count the string loop as a coil, but it doesn't technically coil). Quote Link to comment Share on other sites More sharing options...
psw Posted October 8, 2004 Report Share Posted October 8, 2004 OK, Good...that was going to be my next suggestion...if same poles the string pull would be substantially down...so with your way you've made quite a large field much of which is to the side. This would still inhibite vibration but be less problematic to tuning...except for those strings directly under the magnets! I didn't realize that one end of the string is ground and the other hot (ie both of the jack plug connections are used)...makes sense now...a little confused by earlier comments. I've got a little passive circuit that someone told me about(resistor/cap as I remember) in my strat to protect me from fatal shock. Basically, it's a transparent circuit (ie I can't here that it's there) which uses components of such low value that, should any large voltage pass through it, the components will burn out like a fuse. Come to think of it, maybe a fuse is all that's required, after all the pickup's AC voltage is in millivolts! Also, as the strings already vibrate in the magnetic field of conventional pickups, it stands to reason that some voltages are already produced but are run to ground and no one gets any tingles from that! I had an idea to make a pickup that senses changes in magnetic fields using a HALL EFFECT SENSOR. Basically, this tiny chip senses changes in magnetic fields. Changes are produced by metal strings vibrating in a magnetic field. Sorry, could'nt help putting one of my ideas into the mix psw Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 8, 2004 Author Report Share Posted October 8, 2004 The Hall Effects Sensor idea sounds neat. And the fuse idea would be invaluable, as running 120 volts through your hands each time you touch your guitar if it shorts wouldn't be fun. Although it would add an entirely new meaning to "Man, his hands are ON FIRE!". Oh, and that old idea about the mixer with individual string volumes, might not work to well because everytime you play two strings at once at the same fret, the fret would cause conduction between them. Although that may not be bad, it would limit control. Quote Link to comment Share on other sites More sharing options...
psw Posted October 8, 2004 Report Share Posted October 8, 2004 You've really thought about this! Of course, the frets would short them...good point! I wonder if fretting changes anything to the single conductor coil that the strings have become...effectively shorting them out to each other as you play and shortening the effective length of the conductor...hmmmm By the way it's 240v down here... ...I wouldnt be playing with my teeth thats for sure...perhaps some sort of rubber gloves as a precaution With your intuition...perhaps you'd like to look into my sustainer thread...I could use some new ideas from outside the box PSW's Sustainer Thread cheers psw Quote Link to comment Share on other sites More sharing options...
mushy the shroom Posted October 8, 2004 Author Report Share Posted October 8, 2004 Yeah, I've seen that giant thread. I had the idea that if I were to run a certain amount of current through the strings over the magnets, they would vibrate at that tone. But I'm not sure how to do this so that there isn't any interference with the output signal. Basically I would need a circuit that identifies the frequency of the output current, and sends an amplified version back through the strings.. but there are too many problems. Any ideas? Quote Link to comment Share on other sites More sharing options...
psw Posted October 8, 2004 Report Share Posted October 8, 2004 Now that you would get a tingle...actually I got something by sending a magnetic signal through the string by having the string running through an electro magnet. The problem with these ideas is that there are too kinds of feedback I've identified. There is the feedback that I'm trying to create where you are basically using the string as analogous to the cone of a speaker...the signal causes string to vibrate endlessly. The other is induced feedback where the pickups themselves feedback the signal...go into maximum saturation...then squeal at the combined resonant frequency of the system, when there is no signal. It is the latter that is produced as a signal going through the string from the bridge will be picked up directly by the bridge pickup...just like jamming a mic into a speaker...it doesn't actually make the string itself vibrate. In short, the idea would kind of work...though I suspect you'd need quite a bit of power going through the strings ...but in practice...NO! Sending a magnetic signal is certainly safer but suffers from the same fate I'm afraid The concepts of the sustainer and pickup ideas are similar...at least in the problems that need to be overcome...so it's very perceptive of you off the top of your head...hmmm, smells of parental involvement psw Quote Link to comment Share on other sites More sharing options...
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