Demagnetization of a Pickup/Sustainer

[johnhuntsman]

Hello smart electronics people!

I was wondering if putting the driver for an electromagnetic sustainer system (this one specifically) inside a little steel "semi"-cover (like a steel version of this) with a little steel baseplate (like this one) would affect the magnetic field of it in any permanant way. As in if I had the pickup in said steel contraption for a month or so and then took it out, the driver would be unchanged (it's "magnetic goodness" that is).

Also, sorry if this isn't the appropriate forum for this; it just seemed the most fitting.

[newey]

jh:

Hello and Welcome to G-Nutz2!

I doubt there would be any degaussing effect from just a steel cover and baseplate. But I admit to not really having a good idea whether that is true or not, just a gut feeling, really. So, let's let others weigh in.

[darkavenger]

Welcome!

No, your good to go. Even with the forces produced by the driver channeled through the altered magnetic field you don't risk changing the magnetic field. The forces exerted from the driver are insignificant compared to a force capable of permanently changing the magnetic field. It might be possible over the course of years of use... maybe. Maybe not depending on the type of magnet used in them.

[4real]

Hi and welcome

I'd be very careful about putting any cover on or around the sustainer of any type. The steel bass plate could alter thngs, but even if a non magnetic but conductive material like plated brass (which is common) eddy currents that the sustainer driver might not like could be generated and or interference signals generated by the AC signals generated by the driver into the ground through the cover and so into the signal.

I beleive sustainiac have something on the 'non-use' of covers if you look around their FAQ or the like. It might 'possibly' work though, it is an unknown and there are reasons to fear failure with any cover I suspect, even a plastic non conducting cover that effects how close the driver can get as well. They would probably answer such questions from an email to them.

If you can afford it and are willing to test it before being committed, one might be able to test the systam by holding the driver with cover and all above the strings...it's something of an unknown.

No...you won't damage the pickup or drivers magnetic fields either...however...it might change the sound in some adverse ways of teh pickup when used alone having teh driver next to it. It is designed to go next to pups I believe, usually a kind of blade SC I beleive. Half an HB tends not to be much use....

Consider this sustainer driver of mine...



The driver is sitting next to a tele SCn pickup. On mine the driver is like a signale coil. A sustainiac driver though is a 'bilateral' design, the low strings and the high strings are of opposite polarity so that this will add to the field or detract on string sets...not as a whole. So, if the pup next to it is a SC type, it might well have a noticable effect on the magnetic fields effective 'shape' and strength on these string sets...and HB less so.

Any change in sound on mine next to a stacked pup is quite moderate, but is there...a sustainiac, I don't know...but I beleive they do or used to, advise one can install a pup next to it.

I'm not sure of the size of these things either, if the size of a fender like SC pup, it will not fit in an HB cover like this anyways...so again, perhaps check that with the manufactuer as well.

Hope that helps a bit...

[johnhuntsman]

Thanks. I've actually had the sustainer wired in the guitar for sometime now with the cover/baseplate thing. I just wanted to know if the integrity of my zillion dollar investment hadn't been compromised. It doesn't wok but that's because of incompetence on my part as a "person who solders things". It's nice to know I can take it out and nothing be wrong with it. I just wanted it to look right with the other pickup.

@ 4real
If I had a Fernandes unit, would I be able to put non-stacked Strat-type pups next to it? I know you mention that the effect on a stacked Tele neck pup is negligible but would the same apply to a typical Strat pup? What about a P90? The Fernandes website seems to imply that it can be done.

[4real]

With the 'sustainica' I'd likely be most concerned that the steel plate below might join teh north and south magnetic fileds below the pup and effect teh amount of 'throw' towards the string above it. Consier that the hi three strings and low three strings are of opposite poles. If you were to put a min SC sized HB next to it, well that might be better than a true single coil, hard to say. I thought you could do that with their 'stealth system.

Such thigns will give you a neck pickup, if their wiring is up to it, but you can not operate that pup with the driver so close to it, in case you did not relise that.

Fernandes have gone through few versions, but I believe they currently use an insteresting 'side' coil thing, got a pic somehwere, that means the polarity 'up' is the same across strings.

Put anything next to another pup and alteratios in magnetic fields can occur and so some change is 'sound' can be expected. Might be slight, might be an improvement.

I like noise cancelling pups these days, and for single coil guitars stacks, as my preference. I guess you could put a strat coil next to it or any other pickup. I would not 'ditch' the sustainiac for that though, both are fine and very similar systems. Id be surprised if you could squeeze a typical strat pickup in that cover though, it would be too long surely? All the literature suggests not to cover drivers, especially in metals, if only because of it forces the device a little further from teh strings. I'd be very wary aobut grounding the thing too, the likelyhood is high that eddy currents will be induced that could get into the ground of the amp and create noise.

Experimentation is the only way I am sure to see if any of these things will work on your guitar. I'd be sure the system works as is, then add things like the cover or nearby pickups as you go so you can tell the effect and not commit to anything till you know the things will work for you on that instrument. Sustainers can be notoriously temperamental about such things.

You are not likely though to hurt or demagnetise anything, the biggest risks are in handling or breaking wires and the like in that process I am sure. In many ways susttainer drivers are "like" pickups in their anatomy. The sustainiac a bit like a P-bass or fender z-coil kind of thing, the fernades these days, a bit like the old gibson bass with the side wound coils on either side of the blade. The old kramer/rose ones tended to be mini HB in format. My DIY versions are ultra simple single coils generally, that use their small size to limit the amount/spread of EMI given out rather than dual coils and such.

None are such that the middle or neck pickup can be used while the sustainer is on as these are too close and will pick up the EMI magnetic fluctuations coming out of the driver, which tend to be significant to move the strings, and would lead to uncontrolled oscillation or 'squeal'...

[johnhuntsman]

I wouldn't bother trying to squeeze them both into a cover. I'm not going to bother with that nonsense anymore. Also, when you say that when putting any pickup next to another pickup there are effects on the magnetic field. Is this the case with PAF humbuckers too? The magnetic field of one PAF coil without another PAF coil next to it has an effect on it? Would putting to Strat coils next to eachother turn out for better or worse?

[4real]

Oct 13, 2012 15:09:37 GMT -5 johnhuntsman said:

I wouldn't bother trying to squeeze them both into a cover. I'm not going to bother with that nonsense anymore. Also, when you say that when putting any pickup next to another pickup there are effects on the magnetic field. Is this the case with PAF humbuckers too? The magnetic field of one PAF coil without another PAF coil next to it has an effect on it? Would putting to Strat coils next to eachother turn out for better or worse?

Well, perhaps some more details of your proposed poject.

A device like a sustainer driver puts out a pulsing magnetic field which, with the strings in it's sway, so vibrates the strings. A guitar pickup sensees the variations in the magnetic field of the strings vibrating in it, so they are very sensitive. They therefore will 'pick up' this strong vibrating magnetic field and so cause an uncontrolled feedback loop, much like shoving a mic in front of a PA speaker, resulting in runaway 'squeal' feedback. It's all a balancing act of power and distance between the driver and source pickup at the bridge. This is why you can't use the pickups closer to the driver. In fact, on mine at least, any other pickups will generate from the driver when it is on that can get into the signal and so it is not enough to simply 'deselect' the pups, they need the ground disconnected as well. Hence, with the cover idea, eddy currents will be generated and if grounded could get into the earth signal and so into the amp or create interferance that effects that affects performance and creates noise.

...

Yes, putting a pickup or even substantial metal material near a pickup will alter the 'shape' of a magnetic field and so the area of string and other factors that can effect a pickups sound and performance.

Consider the idea of simply holding two magnets near each other. Like poles will be repelled, opposite attract. On an HB pickup, ou have two opposite pole pickups near each other and they are most strongly attracted to eachother. This creates a low wide shape to the field and so the area of thye sting sensed resulting ina wider window of string that due to cancellations and such, a more 'midrange' sound in general. A single pickup has far more 'throw' and a far narrower window, resulting in part with their brighter sound. If you were to put two opposite pole SC pups next to each other, the field will be again largely attracted to each other. So, more like an HB. Iif the same, the filed lines will be repelled away from each other and go even wider.

Suppose then that you were thinking of using two single coil pups next to each other, rwrp like an HB arrangement. Even if you were to 'split' the 'pup' so oy one coil was being used, the nearby magnet of the unsued coil will still create the same magnetic effects as it is still there, they can not be turned off. So then, the 'split' sound would not sound like the same single coil on it's own.

With the sustainiac driver, it is bi-lateral, so that half of the strings are magnetised nth, the other three sth. So, if you were to put a SC next to it, for both the driver and the pup, the magnetic field will be attracted on half the strings and repelled on the other. Adding magnetic strength on half and reducing it on another...resulting in a change of performance across the strings and could cause effects such as some strings are louder than others (or the driver less efficient at driving the strings) or perhaps the magnetic field pulling more on some strings, potentially so they are pulled out of tune and intonation, etc.

So, experimentation would be the only way to discover how things might be affectted and if the effects are such that the driver fails to be efficient enough without adding so much power that it will be 'heard' by the source or bridge pickup.

That is not to say that one can't do these things, just that all magnetic things will affect each other if close enough in various ways and the design of them matters quite a bit between dual and single coil designs, both pickups and drivers.

[johnhuntsman]

I know you said to experiment, but do you think two Strat coils (maybe these) in series would be hotter than a humbucker (maybe this one) with an output comparable to each individual coil. Also the DC resistance of the "Strat-bucker" would be the sum of the DC resistances of the coils that make it, correct (e.g., two Mother's Milk bridge pups in series would be 13k ohms)?

Also if a humbucker is hot enough to drive a sustainer with its coils in series, could it do the same in parallel?

On an unrelated note, I noticed after Googling about a Kahler trem that you have one on your Tele. Have you had trouble with string breakage, and if so, how'd you fix it?

[4real]

I can't really speak to particular pickups, but if you put two coils in series, generally you are adding them together. The resistance is not the whole story. In parallel the reading would be 1/4 yet it is not 1/4 as loud when one does that kind of thing...series is louder, but not twice...does that make sense.

As for the sustainer, some commercial sustainers like the fernandes I thought used their own poprietory pickup for the bridge that comes with a kit. You certainly need to be noiseless, but there is more to it than that.

Different pickups will have a different frequency response, it's not just about power. Generally when you get hotter (not necessarily a good thing, I avoid them) you get more midrange and 'mud'. So, if this sensor is the one going into the sustainer, it will drive the strings with this kind of filter and perhsp...have trouble with the high strings as a result, have the low strings overwhelm all others, all kinds of effects can occur.

Generally mine have been fairly forgiving, but certainly it has been things to consider. I know that a bright single coil has not worked well at all. In large part as a none noiseleess pickup or bad wiring in a guitar will creat noise...noise goes into the sustainer circuit, which is an amplifier, it will be put out many, many times louder. This 'noise' is generally of a high frequency and unrelated to the sustaining of the strings and will be sensed by the pickup and so be more suceptible to things like fizz and squeal and will prevent you letting the sustainer have adequate gain to do it's job, at least work as well, as you will need to turn it down to get the effect without squeal or at all.

...

The kahler, these are expensive but extremely well built and versitile full range floating tremolo's with the added benifit that if balanced right, you can lock it on the common hybrid models, and you don't need a huge spring cavity, so more wood and strength is left in the guitar.

Any trem though largely depends on the other end of the guitar. Kahlers come with a locking nut and ahve easily enough up and down pull as any floyd and such. Certainly enough up pull that if you pull it 5 semitone or something, no strings can take that kind of added tension without breaking it. But then, who plays like that, EVH's trems only go down you know!

Otherwise, the tele did need a few tweaks. Tele's are very flat guitars, so to get enough breakover on the rollers, particularly the high strings, I neede to shim the neck to achive that, otherwise the high e would sound like a sitar. Some go so far to actually sink the kahler into gutiars to make the 'flater' but my tele is as flat as they can be. The bridge saddles, which don't move' I think it is the intonations screws just behind the rollers, they are slightly domed so some replace them with flat heads, or againa slight shim so that the strings don't touch.

On that tele I have an LSR roller nut, no string trees and quality locking staggered shallers, they come with a locking nut, but I don't like those things. I also use 10-46 strings on it. I don't recall ever having broken a string once it was set up, but perhaps that is the way I play. There is a sound clip in that thread that shows how far the kahler will go....as well as my own sustainer thing, which is different again from the commercial units and was suffering a bit of a flat battery by the end. Be aware sustainers eat batteries typically, you need to be able to get to them to change them for sure.

It does not pull up on the bridge when you depress the arm, it has something of a bigsby floating feel, so if you depress it all the way, the strings can actually stick to the pickups and you can take the strings out of their little hooks LOL. You can go up as much as you like, but then you will break something I'm sure.

Generally that guitar plays in tune remarkably, I was travelling with it in the back of the car with the arm in and a soft case, and it would be intune still at the other end of a 100km journey on an aussie afternoon, so that says something for the whole system.

However, they are definitely not cheap, especially if you do tuners and nuts and all that to get that kind of performance. Find 'wammi world' on the net who I believe have the best prices and great service.

Both sustainers and trems need special care and consideration, as you can perhaps gather there.

[johnhuntsman]

Thanks for the info. I ask about the Kahler because I have an OEM Kahler on an old Peavey Vortex from the 80s (my father's old guitar) and it has trouble with the high e breaking; and then I was thinking about buying a Kahler for the guitar with the sustainer but I don't want to have my high e breaking on that guitar. You wouldn't happen to know how to solve said issue (other than soldering my e string every time I replace it or buying different strings that is)?

Also, do you think it'd be possible to use 2 P90s (in parallel to negate potential muddiness) to drive the sustainer? Rather than having a side by side set up though I'd try to mount one above the other at the bridge position (imagine the bridge cover on a Rick 4000 but taller and with a P90 hanging off of it; there would be a P90 under and above the strings at the bridge position).

Here's another pic of a Ric bridge cover on an actual Ric.

Matt Bellamy from Muse has several guitars with Fernandes sustainers and P90s in them (here's one; although only one P90 is in the actual bridge position and the other is stuck awkwardly next to it) and I know that his guitars work fine.

[4real]

Thanks for the info. I ask about the Kahler because I have an OEM Kahler on an old Peavey Vortex from the 80s (my father's old guitar) and it has trouble with the high e breaking;

I'd/we'd need to see photos and details and any differences between the old and new versions and especially, whre the string is breaking...right on the ball? etc...

They can be a little tricky to set up and problems may not be obvious. You need a decent breakover the bridge rollers,a neck tilt can help add more. There is also a small screw that holds the saddle in position for intonation that is domed, it is possible that it would appear to be working ok, but rubbing on this screw in use and so 'cutting' it over time.

Also, do you think it'd be possible to use 2 P90s (in parallel to negate potential muddiness) to drive the sustainer?

I can't really know the tolerances of the commercial systtem, nor my own till tested. There are 'stacked' P-90s available for noiseless opperation. I couldn't say it would work but might be a bit skeptical.

The kind of sound/frequencies may be different than expected and would effect operation, but it might work. I'd not do it in parallel myself, but I'd not use that kind of thing, the extra dummy coil would change things anyway...so who knows what it would sound like...

As for a cover over the pickups...well that's a bass which is different, but on a guitar that would be seriously in the way otehr than perhaps a lap steel where such things are traditional I believe.

So, perhaps a thread on this project or at least an idea of the bigger picture is in order and what you are wanting to acheive.