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psw

Sustainer Ideas

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Hi there

I'm working up some ideas for a purpose built guitar for the sustainer...

You can have fun flaming the design...or making suggestions...here:

PSW's Project Guitar : Reverse Strat / Sustainer Guitar - Design Link

:D

psw :D

PS...I bumped myself onto page 51! There's some good stuff on the previous page plus a circuit that I'm using on the last post...for all those people who keep PMing me about it!

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OK well sorry i havn't put in any input to the thread for a while but ive been busy, since I sort of put this idea to the forum in the first place a few pages back, I was wondering if someone could give me a quick low-down as Im about to attempt it for myself. :D

By the way GREAT idea using a stacked singe coil!!!!

How well is it working? Does that little gem thing work well enough?

How close can you have the driver to the bridge PU? -(im thinking to try it in the middle PU place)

Sorry I have skim read the last few pages but im slightly confused.

How do you make it do the harmonic thing, (using a DPDT switch am i right?)

Anyway this is a great thread and very constructive.

Thanks Matt

:DB)

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Thanks Matt :D

How well is it working?

Well it's sustaining great. A little trouble with the high e. You seem to get more drive from the centre of the coil (d,g,b strings) and the A and low E because they're thicker respond pretty well as there's more magnetic material (steel) in them to work on. This is pretty normal with sustainers and you have to compensate by having the high strings closer to the driver. There is the possibility that stronger magnets under the higher strings might improve things, so that's something I've yet to explore on this driver.

Otherwise, everything's cool with the pickup/driver combination. Will need to install it to get a true indication of how the pickup performs. I have an identical, non-modified pickup to compare it with, so we'll be able to see what effect, if any, having the driver on top of it's coil has on it's tone and performance.

Does that little gem thing work well enough?

Well those runoffgroove.com guys have a version called Ruby which is a better implimentation (and simpler too) of the LM386 chip. A couple of other people are trying it out.

I'm using basically the same thing. The circuit is on the previous page and is known as the CHamp (down here in Oz) and is available widely in chip form. CHamp stands for Cheap and Handy Amplifier. It does not have the buffer (transistor) stage of the Ruby so I have to use a preamplifier. I've been using a modified PreCHamp kit from the same designer. The designs are very generic and are interchangable. I'm still looking for a more compact preamp. Perhaps some of the electronics masters here (Ansil, LK, etc) could show us how to get more gain out of the buffer section of the Ruby. Otherwise, Tim/onelastgoodbye, is using it as is Emre/transient. If you have high output pickups or an active system, you may not need the preamp gain that I'm using as I've got very low powered single coils in my test guitar.

How close can you have the driver to the bridge PU? -(im thinking to try it in the middle PU place)

It generally seems harder to drive from the middle position. It can be done but it's a balancing act. The more power the more EMI the more it will interact with the driving pickup and go into oscillation.

It's very hard to control as the driver produces magnetic pulses that not only work to vibrate the metal strings...they also travel along them and are sensed by the pickups if they are too close. You still won't get all pickup combinations necessarily anyway...neck and bridge seem to be problematic...even if you can get the neck or bridge pickups to operate while the sustainer is on.

It's certainly something that I was endeavouring to do early on, but now I'm looking at the sustainer a bit more as it's own pickup selection. It's such a responsive and interactive device with a sound of it's own that the lack of choice of pickups is not missed as much as you might think.

How do you make it do the harmonic thing, (using a DPDT switch am i right?)

Basically you wire the output wires (to the driver from the amp) to a DPDT switch (6 lugs, 2 positions) so that they can be reversed...exactly the same as a phase selection switch for a pickup.

What it does is this.

In one position, the sound of the strings vibrations is transformed into electromagnetic pulses by the driver after being amplified and these pulses continue to resonate with the string, the sound of which is picked up and around it goes in a continuous feedback loop.

In the other position, the signal is reversed, it is exactly out of phase with the string. Logically, when the string physically swings up then the driver is trying to physically pull it down! The driver is actually working to stop the string vibrating!!

Now, you may expect the result to be no sound at all, right....wrong!

This is where the harmonic series comes in. The string not only vibrates at the fundumental vibration, but at various harmonics related (mathematically and physically to it) and in large part goes towards producing the tone of an instrument. This is illustrated by when you lightly place a finger at the twelth fret to produce the octave harmonic of an open string. What your finger does, is suppress the fundumental note and bring out the 1st harmonic...the octave...which is vibrating at twice the speed of the fundumental. So at the twelth fret, the octave harmonic is actully moving up, while the fundumental is going down.

The phase reverse switch therefore, like your finger, suppresses the fundumental (works to stop it vibrating) but drives the harmonic. Usually it is the octave (1st harmonic) but often the driver is suppressing both the fundumental and the 1st harmonic, by virtue of it's fixed position (it is not alway's 12 frets from the note). What it will now do is drive the 2nd harmonic, which is the octave and a 5th higher. This is like the harmonic found on the 7th fret.

This Harmonic switch will drive the strings at harmonics, but while the octave harmonic is more usual, some notes will come out at the 5th and others maybe even higher order harmonics. It's not really predictable. But that's where knowing the instrument and how this device interacts with it comes in. The same note, played on different strings, different frets, different lengths from the driver, will produce different harmonic effects.

So, the more you play with it the more you can control what will come out, and these "effects" (like overblowing a saxophone) will become more musical. Not to worry about that too much, because, as the harmonics are related to the original note and seem to make some kind of musical sense...at least in improvising.

So this Physics of string vibration gets to the heart of what's going on here. But it does draw some questions about how the driver interacts with the strings vibrations as notes are fretted higher up the strings...and for you, if the mid-pickup position (if you can overcome the EMI problem) is really the best place for the driver.

If you look at the way the guitar's frets are spaced out, they get progressively smaller as the string gets shorter. This too is related to the harmonic series and string vibration. So, a pickup closer to the bridge (the end of the string) is going to have harmonics very close together. You can get them at the nut end of a string also at the 4th, 3rd and 2nd frets (but not right on them) just as you do on the 12th fret harmonic. So the closer you get to the end of the string (the middle is closer than the neck position to the bridge for instance), the closer these harmonics are and the harder it is to drive these or the fundumental.

That does not mean it's not possible. I was driving strings just ahead of the bridge which is absolutely a null point for all vibration. No vibration where the string actually crosses over the string. Also, you can drive strings on the 21st fret...very close to a veck driver without a problem. The fretted note is another one of these null points too! So, when Tim reports that he only gets the thing to work at a particular location, we have a puzzle. There are a lot of puzzles here...That's what makes it interesting I guess.

Anyway this is a great thread and very constructive.

Well, I hope people appreciate the effort to keep at it. I certainly wouldn't have kept at it without all this encouragement, so thanks a lot Matt and to all you guys. I do think we are at a stage now where people need, if they want to do this, to try it out and report back what works for them.

I guess there is more that could be said about string vibration and the placement of the driver and different fretted notes, but I don't what to further confuse people. You really don't have to know the theory...have some faith that the idea is simple enough as is the technology, and have a go!

psw

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No Its all good, I understand what you mean and how strings/waves/fundamentals etc work, I was just curious about how the DPDT worked. But thanks for a very informative post!!

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That's OK Matt...The post wasn't just for you :D . Even though I do know this stuff too I still haven't got around some of the results I get from testing the sustainer.

For instance, I'm having trouble driving the high e....but...on notes fretted above the 12th fret it seems to work ok. Perhaps there are phase differences at those frequencies lower down that string but, theoretically, it should be harder to drive that string at the highest fret...well so I would have thought.

psw

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Hey Guys,

I've been keeping up with this thread for quite a while and I finally went out and got some wrapping wire to try my hand at a driver. Hopefully I'll get some experimenting done this weekend and have something to add to the conversation.

I just wanted to chime in and say to keep it up and that this thread is really interesting.

Thanks!

Mike

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:DHi Mike...that's geat to hear...the more people who do some work on this the faster it will get together!! There must be a lot of people like yourself because we're at well over 14,000 visits now...I hope some others of that number will be giving it a go too! :D

For the curious who can't get enough of the sustainer thread...the old ansil sustainer mod thread resurfaced again recently. Here's a link to some recent conversations on some of the theory and experiments I've tried:

Ansil's Sustainer Mod Thread - Recent Discussions

Other than that, some words of encouragement. There is no reason for anyone not to get a result of some kind from a simple coil, magnet and battery powered amplifier. Although this thread is very long it's wide ranging and took a lot of detours.

Don't let that put you off...the principle is simple : The vibrations of the strings are picked up by the pickup, transformed into electric energy by it and amplified, the driving coil transforms it into electromagnetic pulse that in turn vibrate the strings. And around it goes infinitely...or until the battery goes flat B).

Let us know how you go, Mike...they'll be plenty of wire left over to make any number of drivers if you want to try variations.

Best of luck

psw :D

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I know this post isnt paticually helpful to the topic BUT i really do think this should be pinned

Reading through this there is SO much to learn and with so many people contributing there is no reason why this shouldnt be pinned and become usefull for many others... anyone else agree?

~~ Slain Angel ~~

P.s Great topic everyone truly informative... might give it a go soon

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Just one more thing....50 pages....12,718 visits....and 735 posts! (some of them really, really, really, long!)

I think this *really* qualifies for a pinned topic...

I know this post isnt paticually helpful to the topic BUT i really do think this should be pinned

Reading through this there is SO much to learn and with so many people contributing there is no reason why this shouldnt be pinned and become usefull for many others... anyone else agree?

~~ Slain Angel ~~

P.s Great topic everyone truly informative... might give it a go soon

Is being Pinned a good thing?...perhaps you need to report the post to bring it to the moderators attention...Anyway, It's quite a saga this thread. I hope you do give it a go sometime Slain A....Meanwhile:

I'm working up some ideas for a purpose built guitar for the sustainer...

PSW's Project Guitar : Reverse Strat / Sustainer Guitar - Design Link

I seem to have settled on an outline so hopefully I'll be able to get the thing together in the near future and show off the DIY sustainer...not to mention solve the little switching problems and stuff.

Anyhow...eventually we might be able to put together some kind of tutorial which will make it all a bit clearer once there is a clear formula to the driver circuitry and installation...and a few people have tryed it.

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PSW... im currently about to go through my GCSE exams (final compulsory school exams) starting tuesday and ending 21st June... as soon as they are out of the way.. ive got till september to do what i want... So that will give me plenty of time to experiment... also give me a chance to finish of a new project for my guitar ive started

Good luck PSW great thread here

~~ Slain Angel ~~

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Quick update:

I did some tests yesterday. My setup was a strat running through a homemade Tubescreamer for preamp and then into the 386-based Ruby circuit (without the buffer section). I wrapped some 28-gauge wire around the bobbin of a horrible old pickup from a Kay guitar. I got up to 7.1 Ohms before I ran out of room. I put wood glue on it as I wrapped to pot it. The bobbin was nice because it's short and the magnet just sits in the middle. So no pole pieces to align.

Anyway, I got some horrible squeals some of the time, and some nice harmonic feedback-type infinite sustain other times. The best is the low E string. It sounds like a low level perfect feedback sustain on the string and you can just slide around the notes. I love it.

The B and high E strings don't even budge, but the A, D, and G can be coaxed into vibrating. I need to wind a new driver and pot it better, assuming that this is the reason for the squealing. But for only an hour of setup time and circuit breadboarding, an hour of coil wrapping, and not even having to take the pickguard off the guitar, I was really pleased with the results.

I highly recommend experimenting with this stuff, it's really fun!

I'll keep everyone updated when I get more time to play.

I think that getting a nice sustainer up and running really is a fairly simple thing, much simpler than I had imagined.

Thanks to everyone who's contributed to this thread!

Mike

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:D

I think that getting a nice sustainer up and running really is a fairly simple thing, much simpler than I had imagined.

Thanks to everyone who's contributed to this thread!

Mike

Wow...I'm glad you've taken the plunge....so it doesn't work perfectly...it does work, right!...and you've got the basics for taking it to the next step!....Congratulations! :D

Now...the tubescreamer preamp is fine but may be adding to the squeel problem by squaring off the frequencies and adding compression (in otherwords sending a distorted signal out). But it's a start...perhaps a different preamp will get better results.

28 guage wire? My best drivers have used 0.22mm, I'm not sure what guage this would be but it sounds like perhaps it's a bit thicker. The thickness of the wire allows more power to run through it and a result has a lower resistance for it length (or number of turns around the bobbin). Too thin and you cant put enough power through it. I used 0.125mm with poor results. Tim/onelastgoodbye used 0.03mm and this only slight additional thickness mean't he could only get half the resistance I was getting in a smaller coil.

Anyway...it's a balancing act. The right coil size, core material, wire guage...once it all comes together you'll soon overcome these problems. I really think the driver is the key. I've been using the same preamp/amp setup for a year now and it has worked on numerous driver designs and runs quite happily from a single 9 volt battery.

My work has led me to aim for quite small compact driver designs. I feel that these contain the EMI, which causes the interferance with the other pickups, and so reduce the squeel for a given output. Basically more output working on the strings, less straying about and causing interferance and oscillation (the squeel).

Potting certainly helps, but you may be producing noise in the tubescreamer that's causing the amplifier to oscillate (squeel), so it's something to think about. There is a school of thought (LK) that suggests that the tubescreamer though, is the perfect type of preamp to drive the strings...so who can say!

Yeah the lower strings respond better because they vibrate at a lower frequency and have more magnetic material (steel) in them for the driver to work on. In order for the driver to drive the strings on the higher strings, not only does it have less to work with and a higher string tension, the driver has to change magnetic states much more quickly.

Here's a common analogy.

Imagine that the drivers coil is a hose. The thinner the hose, the more difficult (resistance) there is to water flowing through it. But, with sufficient pressure (amplifier power) you can produce a very powerful jet stream. A thicker hose will alow more volume to go through (with less resistance) but you will need a lot more pressure (power) to get the same force from it.

Now, imagine that the pressure has to continually reverse direction (with the + & - waves of vibration), there will always be some lag between the response of the water flowing one way and then having to back up which will inevitably be different from the actual vibrations (of the physical string) that it's trying to emulate. So, at times it is working against it's own current and the response is sluggish. The higher the frequency...the faster the direction has to change...the more out of phase it will be and the less responsive the device.

Also, consider the core material. The purpose of the magnet is to apply some attraction to the strings. The coil in the driver alternatively applies more attraction, or less causing it to vibrate. It is necessary that some magnetic environment be set up for the driver to work efficiently. However, as the coil changes states, so too must the core or magnet. Different core materials respond quicker and retain their magnetic state differently. Some will attempt to hold on to their polarity for longer also making the device sluggish to respond to the constant changes in magnetic states induced by the coil and ultimutely the vibration of the string.

But...it appears not to be rocket science and there is quite a large margin of error for which really positive results can be had quite simply. While previous patent designs have put a lot of enphisis on correcting for phase differences and in pumping more power into the system...I think the biggest advances are to be found with trying quite simple variations in driver design.

Fortunately, I think I might get at least half a dozen worth of drivers from a small reel of wire (about A$7 worth) and the magnets can be reused for successive designs. So the cost is minimal and the circuitry remains fairly simple.

Anyway...great stuff Mike...the important thing is to note how much fun it is when you get something out of it. Now imagine that you got that response across all stings...super fun. While my high e below the twelth fret seems to be problematic on my current driver, the things you can play...just sliding and tapping away...is so good.

So, keep it up, and keep up the reports on how much fun it is...that's the essence of the whole thing after all! The more people working out their own variations succeed, the more we'll get a sense of the ideal driver and the less experimentation we'll all have to do as a result!

Fantastic...I'm glad that after all these pages and contributions, etc...we're starting to get some positive results.

psw / pete B)

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... My setup was a strat running through a homemade Tubescreamer for preamp and then into the 386-based Ruby circuit (without the buffer section)...I got some horrible squeals some of the time...
I think you're on the right track using a bit of compression ( from the Tube Screamer) to drive the power amp. Try backing off the gain and rolling off some high end to control the squeals, and you'll probably be pretty close - since the diodes in the feedback loop (of the TS) will round off the peaks instead of hard clipping them, you'll have mostly 2nd and third harmonic distortion, and a little lowpass filtering will make the sustain a lot less "fuzzy" than overdriving the 386. HTH - keep us informed on your progress! :D

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Now...the tubescreamer preamp is fine but may be adding to the squeel problem by squaring off the frequencies and adding compression (in otherwords sending a distorted signal out). But it's a start...perhaps a different preamp will get better results.

Potting certainly helps, but you may be producing noise in the tubescreamer that's causing the amplifier to oscillate (squeel), so it's something to think about. There is a school of thought (LK) that suggests that the tubescreamer though, is the perfect type of preamp to drive the strings...so who can say!

Good to have you back on the thread LK.

This is one of the benifits of a number of people working on the idea. Perhaps Mike is on the right track with the TS! I think I was getting a bit out of my depth with my water analogy there...still perhaps it will help people understand the variables...wire guage, core material, magnet strength, preamp signal, amp power...that make up the sustainer system.

Keep playing and having fun with the "experiment" Mike!

psw

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Hey guys,

Thanks for the encouragment, LK!

I think that finding a preamp that works and posting those results is pretty important. I know that if I found this thread and it said "Here is a schematic and board layout and all you have to do is solder the circuit and wrap a coil to get a sustainer" then I would jump all over it.

In short, I think that a standardized preamp-amp schematic would really take the fear out of a lot of people that want to try this out.

psw, I looked again and my wire is actually 30 gauge, which is 0.25mm diameter, so it sounds like I'm alright in that respect.

I tried turning the TS (tubescreamer) on and off and playing with the gain for quite a while, and that made a difference, but my 386 "power" amp was set to max gain, so maybe the preamp and the 200x amp are combining to make the squeal. I'll put a gain pot on the 386 and play with that soon, hopefully.

I've given this stuff a lot of thought, about compression and squarewaves and magnetic field responses, but I still tend to flip-flop on whether or not the TS is a good preamp choice. I should be able to add more to this discussion (I'm actually getting a PhD in electromagnetics in the next couple of months), but I don't have any revalations other than to say that everyone should experiment so we can standardize this thing. And as I said, I think a preamp/amp schematic and layout would be a giant step in that direction.

Anyway, I'm building another driver, and I'll keep you guys updated.

Mike.

PS....What is it about this thread that makes posts so long? I don't think I've ever posted anything this long before.

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I don't know why the posts are so long but it is catchy...and popular!

PHd in electromagnetics! Just the kind of fellow we need.

Well, I think the only problem with the circuit I'm using for my preamp really is that it's bigger than I'd like. Also, both this and the LM386 are built on circuit boards from kits with slight modifications, and since I'm in Australia, I can't really advise about a suitable, or identical substitute.

Still, looking at about AU$20-25 for the amp, preamp, pot, switches, etc. Then looking at say another AU$10 for the winding wire, etc...enough to make quite a few driver designs.

LK, Ansil or anyother electronics geniuses....is there any way of taking the Ruby Circuit and giving that buffer stage...

Ruby Amp Details

Although I keep refering back to the Ruby, it really is just a typical LM386 circuit just like others I've mentioned and the details of what I'm using previously given. The preamp seems like a simple problem...I just don't have the skills and knowledge to do it...though I've tried.

I think it's easy for people to get overwhelmed with the "electronics" side of things and to think that the secret is in the circuit. It was LK all those pages ago that encouraged me to focus on the drivers and I think that was good advice. I may have gone a little too far in some of my ideas to get something that performs better, is smaller, installs without Mods, etc...high ideals, but took it out of the realms of DIY! Still, discovered some interesting phenomena that may one day bear fruit I guess.

In the meantime, we are getting closer to a standandized formula. Wire guage, LM386...I think we'll have the ingredients down pretty soon. How people are going to install these things in their guitars is another thing. That's kind of why I've gone down the track of replacing or modifying the neck pickup to a pickup/driver combination. The other approach is to make really slim drivers that could be surface mounted. You're still going to need to find a place for switches and knob, the circuit and battery, etc. Again, we did look at some really cool ideas for a surface mounted control box.

For me, I'll be installing it in a purpose built guitar. Then we'll really see if the thing is just a gimmick, or a valid musical extention to the instrument!

psw

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UPDATE: WORKING SUSTAINER!

So I wound a new driver and wired up a simple opamp preamp. The new driver uses rare earth magnets that I took out of a hard drive. I slipped it under the strings of one of my guitars, and it works like a dream!

With one exception:

The 386 seems to give out in intervals. I pluck the string, it goes into a beautiful sustain, it builds up to a level and then the Ruby circuit cuts out and the string dies down a bit, then the Ruby kicks back in and it starts building back up. This is about a 8 second cycle with 5 seconds of great sustaining and 3-4 seconds of cutting out. I'm gonna try replacing the 386 chip and hopefully that will fix it.

If this small glitch is worked out this will be an excellent system! I went all over the fretboard and every string held excellent infinite sustain except for the high E. The guitar I'm trying has a bit of a quite high E due to pickup alignment, thought, so that may be the problem. But seriously, when the Ruby is working it is flawless. I love it. I was just touching the string without picking and the sustain would kick in and I could slide it all around.

Any suggestions on the cutting out problem would be really appreciated. As soon as I work out that bug I'm planning on posting schematics, driver winding instructions, and sound clips. I really think this is something that anyone with any soldering capability can easily do.

Thanks again to PSW and everyone else that has contributed to this. Let's keep it rolling, it's almost there.

Mike.

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sounds like there's been a lot of developments recently! :D can't wait for some sound clips!!

I'm still playing with some silly ideas and I have some spare time soon so I might have a go doing some building :D

I wonder if I have any chips lieing arround.....

if I get arround to doing anything I'll report back

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:DNow you know what I've been on about :D

I'm so keen to see your op amp preamp. I tried and tried but I can't work out why I couldn't get the results I was after...

As for the cutting out...it sounds exactly as if the battery is just loosing juice. The device runs off current not voltage so it takes a mighty drain on batteries. Could be time to change the battery. That's why I've been using rechargables. I have a LED on when the thing is activated and you can see the thing faulter and recover as you describe when the battery start's to loose the ability to deliver the current required.

Try running it from a powersupply...this will provide all the juice you'll need.

Also consider that, (I assume) you were running the tubescreamer from it's power and the LM386 from another battery. Now you're asking one battery to run both the preamp, poweramp and the driver. I'm able to run mine quite happily from a single 9 volt for quite some time before I experience these problems. Perhaps your preamp design requires more power than is necessary...there are low power opamps that may better suit.

Battery Drain is always a major problem. Fernandes I believe address the problem by using two 9 volt batteries. Sustainiac us the new D class switch mode amplifiers. There's no getting around the fact that you're having to create a reasonably powerfull alternating electromagnetic field and in doing this there will be a high current drain and significant power losses that take their toll on batteries. Both commercial systems are murder on batteries despite these attempts to address the problem. It's the driver that's really sucking up that juice, not the amplification, per se!

Ebow, by the way, fares better because it only needs to create a field powerfull enough to drive a single string and it's input is purely mono (the sound of that string), and it can be physically moved to positions of ultimate efficency (avoiding nodes). Still, it's power drains faster than your average signal processor.

What I've got going is acceptable as far as power drain goes so obviously it is possible. A few pages back, however, Ansil put forward a remote power idea which could supply DC voltage to the device from a power supply...through the guitar's normal guitar lead. Perhaps ultimately, this would be the better solution than increasing and regularly changing batteries and finding room for all this stuff in your average guitar.

Anyway...it's fantastic when it works and you start to think of the avenues it opens up for new stuff to explore with it. The high e is a bummer but not so bad. Mine works above the 12 fret and I think there are some clever things yet to be done with driver design (eg put more Rare Earth mags under the higher strings, change the core material).

Even though this thread has looked at a wide and seemingly fruitless number of experiments...all my devices have produced the infinite sustain effect. Additionally, along the way I have discovered a host of different strategies that could be used on the more conventional driver ideas to address some problems.

Good stuff mike...very encouraging stuff

psw

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Do you have a bit more intel on the class D amps? seems like what they're using in cell phones and sorts, right?

i took a look at the Sustainiac patents and.. whoa didn't know they used 2 separate coils. what's up with that. separation of high and low strings?

On the high-e string not working, I think it's a matter of the driver not being powerful enough, or not being close enough. It has to be reeeeeally close to that string. Also seems to help if you put a big slub of iron underneath (which I guess focuses the field a bit bettter). My crude designs (even without an iron core) do drive the high e, just that some notes perform better than others because of a crappy fretjob.

A good starting point for a sustainer IMO:

1. wide core, say 3-6 mm, can be iron or just the bar magnet itself

2. a flat and wide coil ( 3-4mm high?)

3. 0.2 to 0.3 insulated wire for the coil. 0.2 is easier because it makes for a smaller package.

4. coil wound to 8 ohms (seems to get the best response from the lm368)

5. good potting (epoxy, nail polish, wood glue, wax, errr...polyester filler, paint whatever :D)

6. some sort of amplifier, the Ruby seems to be pretty adequate.

7. some sort of gain control on the amp..too much gain will result in squealing

Keep on sustaining,

Tim

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I absolutely agree...

A flat coil close to the strings...really close.

I certainly have had varying results from the high e. If you look sustainiac have some kind of "shunts" or metal fins under the high strings to address the problem. You'll also see that the circuitry has all kinds of tomfoolery to compensate for phase discrepancies. It will work adequately and quite usefully with the more simplified DIY approach and to some extent our suggested thinner, close coils seem to be very effective at addressing some of these issues than getting all tricky with the circuitry.

Part of my quest for individual miniture drivers was that the whole active element could be much closer to the string. The thin coil design also uses that principle to good effect.

Sustainiac's twin coil design has alternate north and south drivers with reverse signals. Kind of a humbucker in reverse. I've never quite got my mind around what happens between the d and g middle strings where the driver's cross over. You'd think that the opposing forces would cancel out...but I could be wrong.

I think the idea was that in the bigger picture, the EMI would be less due to cancellation as it would be emmitting, as a whole, equal amounts of + & - signals from the driver though to the strings they would feel the influence of one coil at a time.

Fernandes have a similar design, though these driver designs seem to change fairly regularly. They have a stacked singlecoil type device lying on it's side to create a similar effect.

The end result of limiting interferance is the ability to send a stronger signal. More signal/drivers though and you're still looking at more power. I saw an old add where Fernandes were claiming 12 hours of continuous sustain on two 9 volt batteries...not bad I suppose but you'll still go through a lot of batteries!

I was thinking of doing some twin coil designs but for a different reason than these guys. Like my Hex designs, I figured that we could have coils optimised for the lower and higher strings...perhaps a more powerful coil or magnet system...but it may be that people will find a far simpler way along the lines that we've been working with a bit of experimentation and I'm terrible at overcomplicating things so, for now, perhaps we should'nt go there or well end up with six drivers as I had before!!!

One thing that could really influence response is the core material. Ferite would probably be ideal. It's just impossible to cut or shape and difficult to obtain in a suitable format. Otherwise, laminated or powdered cores may also prove useful.

Anyway Tim, I think you got the formula down there and that's good advice. I'll see what I can dig up on class D amps...yeah they use them in mobile phones and such so do come in the kind of outputs we want. I think they may have special qualities (like wide input impedances, etc) that also would be really useful but I'm no expert and you don't seem to find them really easily anywhere...perhaps someone else will know more.

pete / psw

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Alright folks, I think that I have a simple formula to make a sustainer now.

I made another circuit, it works much better.

My first circuit would only give good sustain with hot humbuckers, but this second circuit has enough preamp gain to work with just about any guitar.

I'd like to write up a quick tutorial on how to make this thing that includes the schematic, the steps for making the driver, and maybe some sound samples. So could I write this for the projectguitar tutorials page? I'm not sure if that priveledge is reserved for the "senior" members.

Let me just say that this thing is easy to build and FUN to play with, so I'm sure a lot of people would want to build this. It took me about an hour to build the circuit, 1-2 hours to make the driver, and about half an hour of circuit debugging (stupid mistake). The system I have now is really controllable and I get a nice infinite sustain on every string but the high E. Once again, the high E issue may also be the guitar I've been using. The sustain sounds pretty cool with a clean guitar tone, too.

Anyway, if anyone could let me know the rules on tutorials I'd appreciate it. I'll try to get this info out ASAP whenever I know what to do.

Thanks again to everyone, especially PSW.

Mike

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Posting Of Pictures:

- ALL pics are to be no more than 600 pixels, on ANY side.

- ONE PIC PER POST., except in the Tutorial sections, where you are allowed up to 10 pics per post.

These are the only rules I'm aware of that pertain to the tutorial section. Beyond that, just write your tut up and post it. If you need help formatting it, or just want feedback or proofreading before you expose it to public scrutiny, I'd be happy to help any way I can, as I'm sure would psw or any of the other sustainer freaks lurking about this thread! Great work getting it sorted - I look forward to the tutorial! :D

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Great Mike....yeah as LK said!

Also separate posts for driver, circuit, etc sometimes makes it more clear to read and gives you more options for pics...ie: one pic per post...multiple posts = multiple pics, right :D

The only other thing...for vanity's sake....and so all the related work and contributions aren't lost in time....perhaps you could credit this thread by pasting a link to it in your introduction. Of course when it's there...post a link on the thread too so that the regular reader's of the sustainer thread find it over in the tutorial section.

Other than that, I don't think there is...and i'd discourage a simple..."this is THE way to do it" approach. Simply because there will always be room for improvements and we don't want to stifle variations that could take the thing further.

For instance...your High E's got problems, Tim's got active EMG's, someone with high output humbuckers will need less gain, some may want a super slim surface mount device, others a thin tall shape, mine includes a pickup, getting the same magnets as you use may be a problem....etc.

Otherwise...sure, go for it...anything that will encourage people to have a go is good. I'd love to have done a tutorial myself but this thread...at 52 pages...has taken quite enough of my time really!

Good Luck with it...email me if you want some feedback (pun intended) or anything! :D

psw / pete

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Hi Pete,

sounds like you're getting it all happening with the sustainer..great

I haven't read the whole thread but I'll get to it...

I remembered on the first Roland guitar synth they used 6 tape recorder heads for the hex pickup...I don't know if this info's of any use, but I just thought I'd mention it...maybe they could be used as drivers, they do focus the field in a more concentrated fashion...probably not powerful enough, though...

lovekraft,

I'm sure Godley and Creme were producing Gizmotrons in some quantity...I remember trying one in a shop in Australia back then...I think the reason they stopped was because the company producing them (Musitronics) went bust....(probably from tooling up for it and not selling 'em quickly enough)

The things worked OK...but I think people were reluctant 'cos they were a bit cheap and plasticy looking...especially in comparison to the Mutron effect boxes the company was making at the time...

Peace

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