RM2488

I don't see why it cannot be done. At least, theoretically, it seems possible. As for the fizz, if the sampling frequency is high enough, there won't be any fizz. Definitely higher than the Nyquist frequency, probably more than double of the Nyquist frequency for the highest harmonic (within reason) of the highest note on the high-e string, as processing and subsequent string driving take time.

That being said, McSeem is right- the current DIY drivers are not suited for this function. However, the Moog patent does state that the sensing and driving is both done by the same transducer.

A quick and dirty charger I use (rarely) is easy, if you're willing for a little bit of expense. I bought a D-Clamp (one with 4 inches of movement, and two HUGE Samarium Cobalt magnets. I used Araldite (Very high strength Epoxy) to stick them to the clamp, one on the rotating bolt and one on the stationary arm. Then I glued very thin pieces of ply on them. It works perfectly well as it is. I don't have pictures, but I can try my hand at ASCII art:

..........____

..........|___|

............\\

|||||||||\\||||

||..........\\

||.........|M|

||.........==

||

||

||

||.........==

||.........|M|

||.........__

||||||||||||||||

It's very rough, but I think fairly clear- The two M's are the magnets, the slashes are the screw, and the equal signs are the ply. All you have to do is place the polepieces between the screw and the other magnet, and tighten it. Simplicity

EDIT: Ignore the dots, I had to add them 'cause it eliminates multiple spaces. Now this is why you should use "preview"

*Is their a tonal difference between an unpolished bar magnet as opposed to a polished one?

Nope, none.

*At lot of pickup makers seem to prefer enamel coated wire over poly coated wire is there a sound difference between the two providing the same gauge of wire is used?

Yes, there is. You see, a pickup is a kind of filter... the coating adds capacitance, and the thickness of the coating will also affect the coil size, which has an effect on the sound. Of course, you can make good pickups from both.

*I have read somewhere that there are high and low quality magnets,

If this is true how can I tell a good one from a bad one.

Will lower quality magnets sound worse given the same type of magnet is used.

Grade A crap that certain custom winders or shops propagate. Depends on what you want from the pickup. If you're looking for a soft, clean sound, then perhaps ceramic magnets would be "bad"... but good if you're going for a hot brassy sound. That is not the only criteria, a lot depends on the coil and polepieces as well, I've seen ceramic ones that were mellow and alnico ones that were harsh. Also bear in mind that there are several types of AlNiCo mags... I myself favour rare earth ones, usually Samarium Cobalt.

As you can see, many roads lead to Rome. Experiment, and you'll get the hang of it...

Sustainiac has a piezo-acoustic transducer mounted to the headstock. It works pretty well, but of course, it's also mono. What is bad about the under-string mounted driver is that you can't sustain certain harmonics, namely those ones that have wave nodes right at the driver. My preliminary experiments confirm it, so, as expected. So, an ideal driver would be... mechanical, like you say - a speaker, or a piezo crystal. Just a crazy idea -- if you have a floating bridge, you theoretically can try to attach a speaker coil to it, with a speaker magnet system mounted to the body. So that, it would vibrate the bridge itself. The system is heavy, so, you probably can't sustain high frequencies.

Yes, the transducer idea is very simple to implement... I was not aware it is being done commercially. As far as the higher order harmonics are concerned, only SOME will be blocked, right? If I remember my physics lectures correctly, the one after the fundamental has a node at half the string length, and the one after that has it at one-thirds, and so on. So the ones with the node over the driver would probably be in dog-whistle territory. I mean, except one in the lower order. So perhaps the second order harmonic will be dead, and all other after the seventh... not a big deal, the problem is aggravated with increasing string length, and I doubt anyone would want a fifth-order harmonic on the 22nd fret. But yes, it does make it unpredictable. That's where your project is promising- you could perhaps sense it, and have an alternate driver purely for this situation.

The floting bridge has other issues- for instance, I'd be completely blocking the driver when I pitch bend with the tremolo (damping). Also, it will probably make the other strings move- forced vibration. But I'm sure that happens with the magnetic driver as well.

As for hexaphonic in general, yes, your aversion makes sense, mostly due to the wiring nightmare. I had really hard time DIY'ing it. :-)

My aversion is not due to complexity, but due to the output I desire- if there's high crosstalk, I might as well go for a blade pickup. But at the same time, I need the ability to bend strings without issues... plus I'm not going for the kind of thing you are- I like it barebones. So a traditional pickup makes sense for me. But then again, I have never used a hex pickup, so it is all speculation....

If I were to do it, I'd probably have some uC in the guitar to control it and mix all six into a single output for use with a regular amp. I'd also have a few switches for the extra "settings" and eq. or whatever. When there's a new one required, simply connect it to a computer and send it a new config-file. But hey, maybe that's just me

Besides, my system requires an audio-interface, a laptop, and a 6-channel power amp. Plus there must be some control pedals, and/or on-body pots and switches, that I could read in my software. I'm thinking of using some USB DAQ like this one: http://www.hytekautomation.com/Products/IUSBDAQ.html

But as the major benefit - you can control any parameter you want, or even assign a single pot to control ANY number of parameters simultaneously.

Very, very ambitious... keep us posted!

A string being driven by a sustainer is and can be quite different from that of a plucked string. You might like to consider some of the sound clips...with the tone turned down a little, you can get quite mellow flute'y effects and the sound that is produced is largely a factor of the manner that the string is vibrating, so one should not jump to conclusions about the resulting sound.

Yes, I have heard practically every one of them... Loved the effect it has on chords. Also liked the harmonics on some... not personally something I go for, but I appreciate it nonetheless.

There are problems with driving the string from the bridge end as well, there are a lot of harmonic content that close to the bridge. Most of my hex designs were working towards efficiency and low power to be built into the bridge itself and to use the bridge as something of a magnetic 'sink' in the process...but alas....

As far as Hex pickups are concerned, the problems I foresee are either crosstalk or loss of signal on bending... but maybe someone else can do it, McSeem's project is very interesting and promising...

MY idea of a sustainer was a little different.... I don't know if it is practical enough, or how it will sound. I wanted to attach a speaker driver to the body... behind the headstock is also effective. In essence, it is like being driven by a huge amp at high decibels. But my experiments in that region led me to believe that I would also suffer from very poor battery life, and I'd hate to be tethered to a power line as well as the amp cable. A self-contained system is more appealing... just making the strings move rather than the whole body is more efficient. I also suspect I got better results 'cause I have a floating bridge... easier to excite.

Consider this for instance, the neck pickup sounds as it does, to an extent, because it is placed away from the bridge where things are less harmonically active...so the primary frequencies heard are the fundamentals...so it sounds "smoother" and "bassier" and such. Ok...well, if you are driving the string from that location, and you are driving the fundamentals, the sound produced is largely the fundamental, and so that is the sound that the bridge pickup will produce. So, it is an assumption that the driven string will have the character of the pickup at the bridge, it far more has the sound of the "driven string" more than anything...it's definitely something to think about careful and take in mind for the amount or work that would be required to do differently and everyone pretty much has either failed at, of been unhappy with the results of.

Now, THAT is new to me. Reversing the locations would actually give me the opposite effect... hadn't thought of that...

I wanted to stick to one pickup to avoid bypass.... I favour the neck over the bridge, a nice bluesy kind of sound. It would be simple enough to have an on-off sustainer without bypass. I record less and play live more, so I wanted a barebones system.

But it's an honour to have you take a look at this... very grateful for your insight. I think I'll go for the traditional approach for now and see how it goes from there...

McSeem, looking forward to the hex sustainer- who knows, I might get over my aversion to hex pickups and build one!

The humbucker won't reject the driver mag field completely. It perfectly rejects only fields that have no gradient, that is, namely 60Hz hum, induced by power transformers, etc. In case of the driver, there's a significant field gradient, as the driver and the pickup are placed relatively close to each other (even in case of the bridge and neck positions).

Ah yes, I'd thought of that. My idea is to build a humbucker like this--->Coil A - DRIVER - Coil B

So the gradient across both coils wil be more or less equal. As long as the coils match, I don't think there will be too much interference. And yes, there will be some feedback, but I'm of the opinion that it will be miniscule compared to the strings... but I'm not sure.

If you use a separate pickup as the sustainer source, the driver will induce the signal in the input pickup directly anyway.

Perhaps not, if I use a piezo...

What I really want to do, the simplest possible solution, is using the neck as source and the driver at the bridge. But it seems a lot of people avoid it, I have no idea why.

Another idea that occurred to me is to have two drivers, one at the neck and one at the bridge, and use a piezo as source. Then you can simply select which pup you want, and set the other as the driver. In fact, the piezo can be entirely eliminated, and the source and drivers can be switched (Increases chances of feedback).

I wanna know if there is something wrong with this logic, or if someone has burnt their hands this way before I get to work. Six matched coils, hand wound, is hard work! Maybe I should also think about a winding jig...

Hey

I went through the 300 page sustainer thread (not entirely!) and I think I got the gist of how it works. But I have two questions that may be pertinent to the kind of system I wanna build-

1> Why does everyone put the driver over the neck pickup and not the bridge(using neck as source)?

2> If a humbucking pickup is used, it should, in theory, be able to reject the driver (Common Mode). A small amount may get through, but the loop will, in essence, be broken, am I right? Like this:

Neck pup---> AMP

Bridge pup---> Sustainer source

Driver---> Over the neck pup.

The reason being I like the sound of my neck pup, and THAT is the one I want to use with the amp... of course, using the neck pup as the sustainer source and the driver over the bridge pup is equivalent, and humbucking is no longer a requirement (with lesser tone coloration as the bridge pup will be off!).

The main reason is that I want to make sure I can do it the way I want, before I rip out the old pickups and wind new ones. I've also considered using a piezo as the sustainer source...