magnets

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andydeedpoll

i do love smilies...
hello!

does anyone think magnets would be harmful to most boss/electro harmonix/marshall effects pedals? me and a friend are about to start building a pedal board for me, and while we considered using velco, we didn't like how mucky it got so quickly - we thought about using a sheet of thin metal on the base of the board, and sticking some small magnets onto the underneath of the pedals.

i can't imagine it'd be harmful, but i just thought i'd get some second opinions.

ta!

Andrew.
 
Magnets can & will have an influence. The influence will depend on their strength and location.
Experiment with a magnet and your plugged in guitar cable - play a chord and play around with the magnet near the cable. The do the same around a pedal while in use. Find out whether the influence bothers you.
I don't know about the safety angle though.
 
Magnetic fields and electronic fields are very different, but they do share some common characteristics. Both can cause unwanted noise and make pedals (and other devices) more likely to pick up outside interference. While magnets aren't likely to cause permanent damage to your pedals they may alter their performance. Small magnets do not have a strong enough field to hold much together, so they may not even work to hold your pedals in place very well.
 
thanks for the replies - i'm probably going to give this idea a miss (i was wondering why no one had done it before - if it wouldn't alter performance then it'd be brilliant, i think!)

cheers,

Andrew.
 
andydeedpoll said:
thanks for the replies - i'm probably going to give this idea a miss (i was wondering why no one had done it before - if it wouldn't alter performance then it'd be brilliant, i think!)

cheers,

Andrew.
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I don't see how it could affect performance. A permanent magnet's field is "DC"; that is, it is non-varying over time. Electronic circuits piggyback AC (signal) voltages atop DC voltages all the time - phantom power to condenser mics, for instance - without any signal degradation.

I think it's a great idea and I'm going to steal it. ;^)
 
ggunn said:
I don't see how it could affect performance. A permanent magnet's field is "DC"; that is, it is non-varying over time. Electronic circuits piggyback AC (signal) voltages atop DC voltages all the time - phantom power to condenser mics, for instance - without any signal degradation.

I think it's a great idea and I'm going to steal it. ;^)
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you sound pretty sure! i'm confused now :P

tell me if it works well ;)

Andrew.
 
I'm gonna go with ggunn ...... I also don't see any way it'd affect the performance of a pedal. Maybe if it's a pedal with a tube in it but even then it seems unlikely to me. They stick tubes in amps right over speaker magnets and manufacturers don't seem to worry about that at all.
But for a solid state chip based pedal which is most of them, I don't think it'd affect anything at all. I'm not stating this as a fact since I've never tried it but it seems unlikely to me.
Also ..... some of those newer magnets are definitely strong enough to hold pedals. Like the ones I can use to hold stuff on my ears .... the magnets aren't even touching .... they have an ear between them and they still hold.
I think it's an intriguing idea actually.
 
I don't know much about the physics of this but I have made my own pedal board...alot of the new boss units come with two strips of rubber with an adhesive back which is pretty handy for fastening to your pedal board.
 
Lt. Bob said:
Also ..... some of those newer magnets are definitely strong enough to hold pedals. Like the ones I can use to hold stuff on my ears .... the magnets aren't even touching .... they have an ear between them and they still hold.
I think it's an intriguing idea actually.
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You can buy "super magnets" that are, I believe, used in head manipulators in hard drives. If you used one of those to clip something to your ear, you'd hurt yourself. I've got one that I use to stick notes to my (steel) front door, and I can just barely pry it off the door by hand.
 
I use plastic cable ties for all of my pedals-they hold everything tight to the pedal board-and if you want to change pedals out-you just clip the cable and use a new one!
 
If I'm not mistaken, magnets can interfere with inductors' own magnetic fields and cause audible anomalies if they're strong enough, and close enough. Electrons are negatively charged and will react to magnetic fields. I would hesitate about using any strong magnets near any audio gear.

Now, if you're just going to use some of those weak, thin, flat magnets that come in sheets, it probably won't make any difference.

I'd use Velcro instead, though.
 
Now I'm curious ....... I'm gonna try putting strong magnets against a couple of my pedals when I get the chance. I'll even open them up and place the magnets directly on various components inside the pedal to see if it affects the sound or noise level. I'd just about bet that it'll make no difference at all but there's only one way to know for sure.
I'm positive though, that it won't harm anything permanently. If it does cause noise or anything it's only gonna be while the magnet's in place.
Hardest part'll be getting some strong enough magnets. I think I might have an old speaker outside I could pull the ceramic magnet off of. That's fairly strong.
 
Lt. Bob said:
Now I'm curious ....... I'm gonna try putting strong magnets against a couple of my pedals when I get the chance. I'll even open them up and place the magnets directly on various components inside the pedal to see if it affects the sound or noise level. I'd just about bet that it'll make no difference at all but there's only one way to know for sure.
I'm positive though, that it won't harm anything permanently. If it does cause noise or anything it's only gonna be while the magnet's in place.
Hardest part'll be getting some strong enough magnets. I think I might have an old speaker outside I could pull the ceramic magnet off of. That's fairly strong.
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Yeah, I agree that no permanent harm would come to the pedals themselves. You could try it out with one of those enormous magnets from Edmunds Scientific. :eek:
 
Zaphod B said:
If I'm not mistaken, magnets can interfere with inductors' own magnetic fields and cause audible anomalies if they're strong enough, and close enough. Electrons are negatively charged and will react to magnetic fields. I would hesitate about using any strong magnets near any audio gear.

Now, if you're just going to use some of those weak, thin, flat magnets that come in sheets, it probably won't make any difference.

I'd use Velcro instead, though.
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Electrical charge and magnetic polarity are not the same thing. Besides, a steady state magnetic field is analagous to a DC voltage; the audio is carried entirely in an AC signal, and even a very large DC component has no effect on the AC (signal) component. In the interior nodes of a tube amp, for example, a very tiny AC wiggle (less than a volt) is riding on a very large DC voltage (~400-500 V) with no ill effects.

I doubt that even a very strong static magnetic field will affect the AC response of an inductor.

My money's on "no effect whatsoever", but let the data speak. Lead on, Lt. Bob!
 
ggunn said:
Electrical charge and magnetic polarity are not the same thing.
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Just a comment here - you're right that they're not the same thing, but they can interact. How else would a bunch of wrapped-up wire generate a magnetic field when a current transition occurs?

Oh - and have you ever held a magnet up to a CRT-tube TV? The distortion you see is caused by the electrons emitted from the electron gun having their path displaced on the way to hitting the phosphor on the inside of the tube.
 
wow, some great responses, thank you very much!

i'm going to try this out myself too, hopefully!

thank you!

Andrew.
 
Zaphod B said:
Just a comment here - you're right that they're not the same thing, but they can interact. How else would a bunch of wrapped-up wire generate a magnetic field when a current transition occurs?

Oh - and have you ever held a magnet up to a CRT-tube TV? The distortion you see is caused by the electrons emitted from the electron gun having their path displaced on the way to hitting the phosphor on the inside of the tube.
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Zaphod leave him to it. He's learning physics the hard way:D
 
Zaphod B said:
Just a comment here - you're right that they're not the same thing, but they can interact. How else would a bunch of wrapped-up wire generate a magnetic field when a current transition occurs?

Oh - and have you ever held a magnet up to a CRT-tube TV? The distortion you see is caused by the electrons emitted from the electron gun having their path displaced on the way to hitting the phosphor on the inside of the tube.
Click to expand...

The electrons in a wire generate a magnetic field, that's right, and in a coil, much moreso, because the fields from the parallel wires reinforce one another. A DC current will generate a steady state field, and an AC current will generate a varying field. This is why I've been talking about AC and DC voltages and currents. The AC component (where the audio info is) is not affected in any way by the DC component, be it electrical current or magnetic field.

If you have, for example, an output transformer of an amplifier driving a speaker, you can drive a DC current through the primary along with the signal and it will not appear on the secondary, even though the DC component is making a non-varying electromagnet of the primary. This is because inductance (which is a magnetic effect) works on AC current but not DC. When you apply Ohm's law to inductors, there's a "dI/dt" term, which is the change in current with respect to time, and if dI/dt = 0 (meaning the current is not changing over time, i.e., it's DC), the inductance term totally falls out of the equation.

The reason a magnet deflects an electron beam in a CRT tube is because the electrons have been accelerated to a high velocity. Electrons in motion generate a magnetic field, and that's a good example of that, but it's an example of two "DC" magnetic fields interacting. If electrons could be moved by magnetism alone, you wouldn't need a battery in your car; all you'd need would be a big permanent magnet.

Did I mention that I have a degree in electrical engineering? Sorry if I get long winded, but that's what engineers do, or so my wife will tell you... ;^)
 
Ok, the physics aside. The question begs why use a magnet when there are better, cheaper and easier solutions. My take on it is to use "velcro" which here at least you can get in ribbon form and sticks real good. I use it for loads of things and it definitely wont effect your signal chain.
 
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