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Sustainer Ideas


psw

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Just out of curiosity...how many on this thread have access to test kit? (an oscilloscope & signal generator, etc)

No...early on I started to experiment with PC based freeware signal generators and oscilloscope software...but I got a lot more done when I abandoned these approaches. Some of it was to try and detirming things about the kind of signal that might best drive the string, alternative to the actual source...so square, triangle, sawtooth kind of things.

But I started to get the feeling that these artificial signals and such and my one string "guitar" was too far from the reality of the situation...

And, again...so much focus on the circuit...in the early days there was no thin driver theory or working DIY work to follow. In many ways I was thinking like you hank...I was testing single string drivers and assuming that once I had a driver for each string and tailored it to it's mate...I could just string them all together on a real instrument. Or, that if I could run a driver from a computer generated completely independent source, this would transpose to the reality of a guitar with the signal more complex and taken from a particulr point that moves in relation to the fretting of notes and such.

I have never had an LM386 chip progressively die...I don't really see how it could....but performance will alter with the battery life that's for sure!

These circuits have been generally extremely simple affairs...I didn't nominate the F/R design, but I did suggest that I was aiming and succeeded in a design that worked just with simple low watt amplification form a battery. Much of this was aimed at simplifying circuitry and working the driver designs till they worked. The LM386 is the obvious choice for such a project...others have been tried and discussed...whatever the power amp, the results should be somewhat similar in principle.

The real problem is not with the testing of circuits...much of these simple circuit characteristics are known...it is more what the silent driver makes of them, and as col has been discussing...what is physically going on with the string.

While I can appreciate col's interest in the plucking 'kink' effects...I do tend to dismiss this kind of area of inquiry. It is somewhat true it would seem...you can hear the driver take over the more complex vibrations of a string and settle into a constant less complex sustain...but it is the exact same effect that you will get with feedback sustain produced with a loud amp and standing waves in a room traditionally. As a result, I don't see this is really a "problem" if this is the effect you are simulating anyway! As for the plucking thing...if a string were to sustain as long as the sustainer provides naturally, I suspect the plucking kink would soon settle down and the sting vibrate in a more natural way over time.

But I can appreciate the desire to produce a different more interesting kind of sustain. To produce a more complex sound in my playing, I have tended towards some subtle delay and vibrato...and in recent years the tremolo...to produce a more interesting and adjustable sound with sustained notes and chords...it's kind of like a manual chorus kind of effect I guess. Perhaps those interested in a more interested sustain could experiment in the area of adding signal modifiers into the driver circuitry, re-energizing some of this lost harmonic content and sound 'kinks'.

I can't even begin to imagine how anyone could dedicate the amount of time needed to get results without test tools.

Again...I think that the test tools and simulations work only really on the circuit design aspects of this project...whereas the issues about the driver characteristics and physical vibration properties are as or perhaps far more important...especially when it comes to phase issues. There are so many factors that need to be balanced and interact with each other...that I think it is easy to be mislead by such results anyway when applied to the real world. As I say, I started tinkering with these things and test strings...but this research did not prove very fruitful at all and has had hardly any bearing on the progress of my work.

The LM386 is not the problem. the problem is the way the whole system works. It doesn't matter how hi-fi the power amp section is, the same problems will still exist. The only thing that you could improve radically by updating the poweramp section IMO is efficiency e.g. by using Class-d amplification.

I agree...and I assume that the class-d efficiency refers mostly to power consumption and battery life, not so much the characteristics of the amplification.

Sure, you can get quickly the generic results by following the blueprint by many on here, but it'd be rather difficult to take this project down any new avenues easily, without at least seeing what the signal levels are across the driver (along with seeing if the signal is distorting etc) - without a scope you're literally are stabbing in the dark (or at least stabbing in a very low light room!). How else are you going to see the frequency response of your amp/driver - see what phase changes there are between input & output...& so on?

I kind of see what you are saying...but I don't know that it would help much really. All the same, since you have the tools...want to volunteer for the testing? I can see how you might test the circuit, but the real problems are what the driver is doing...how are you really going to measure that. One way may be to construct another coil and holding it near by, see what magnetic signal is picked up by this on a scope...but then you would need to know the characteristics of the "pickup" coil and take these things into account. Distortions, yes...but you can hear this by attaching a speaker instead of a driver to the circuit...however, what distortions does the driver produce (and phase distortions). Then there are all the physical things to contemplate...string vibrations, driver/pickup distances, fretting and harmonic node concerns...I presume you'd need some sophisticated stroboscope set up. And then, most importantly perhaps...putting all this data together and making any real sense of it... Wire gauge...I used trial and error...

The alternative route is to make a heck of a lot of drivers...hehehhe...here's a small sample of rejects...hahaha

DSCF0292.jpg

With things like magnetic properties...many of us have spent hours tinkering with FEMM....here's a random Hex design idea...

thinhexfemm1.jpg

This can be fun...i mean a valuable learning tool and idea contemplater...but I have found that these 2d constructions are limited in their use once the real thing is actually produced. Further, I have never got a handle on the electromagnetic modeling (I think col had some luck there) so a lot of it was reliant on an internal realization in my brain (ie a dream) that needed to be tested in the real world to see if it had any real benefit...but useful for dreaming up novel designs and understanding driver interaction in novel dual coil and hex like novel designs. Many FEMM models have saved me grief by discouraging me to actually make some of these things.

It occurs to me also, that some of these things can be sensitive to your construction techniques and materials...basically quality and design parameters. This has been shown by people building even the known designs, finding success after building a better quality second driver for instance. So, in some cases, especially with novel designs, failure may in part be not the fault of the design but the specs and quality. The only reliable way of really testing such things I guess...is to actually build these things...

Now...we are looking at quite a bit of commitment here! An example is my mid-driver dual coil design...

driverinstalled2.jpg

Remember this? This was built, with all hope, in an 'era' where dual coil designs were seen to be the 'next step' (perhaps they are)...so there was a lot of discussion and thought into these issues influencing the design. It was backed by my driver making skills from the previous years and my own abilities. It was extensively modeled in FEMM to get a 'feel' for how and why it should work...and several unique processes, jigs and such need to be developed to actually construct it.

However, while it kind of worked...it failed to live up to the 'dream' for all of that. Last we heard from CurtisA he was approaching the same kind of thing with an amazingly good looking bilateral driver and some alternative circuit ideas...haven't heard anything of any results...but I suspect that there will be problems for all the good ideas and quality.

So...while it may seem not that "scientific" to use trial and error testing...it has produced results and is working with real world applied practicalities. However, we have here something I didn't have at the start...an online database of at least some experiments and an online round the clock sounding board and brains trust for ideas...perhaps most importantly some actual working designs from which to move forward from.

It's amazing how this project captures peoples imaginations and the thread keeps going the way it does...perhaps one of the side benefits of all this is the exercising of the mind which can only be a good thing...and learning perseverance and dealing with frustration (something I have lost much of in recent years).

Perhaps I am jaded, but I think too I have learned that no matter ho much I think something should work, no matter how well I build something, no matter how much hope I invest in something...there is always and frequently the likelihood that I was wrong or naive in the endeavour. It takes some courage to sail these waters, hitting your limitations and butting up to the physical restrictions of the world a frequent occurrence...changing course when you have failed a constant companion. On this last, when does one know when to abandon one heading and give up on a good idea?

Sorry...got all philosophical there...hehehehe...

keep up the good work...

pete

Edited by psw
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While I can appreciate col's interest in the plucking 'kink' effects...I do tend to dismiss this kind of area of inquiry. It is somewhat true it would seem...you can hear the driver take over the more complex vibrations of a string and settle into a constant less complex sustain...but it is the exact same effect that you will get with feedback sustain produced with a loud amp and standing waves in a room traditionally.

Feedback from a loud amp in a room damps some overtone harmonics and boosts others, as you move you can control which.

Feedback from the sustainer (neck driver bridge pickup) actively damps all of them, and you don't have control over this.

So obviously the two are not the same.

playing with loud amp feedback, pinch harmonics come alive, as does the harmonic complexity of the guitars sound.

playing with sustainer feedback the opposite is true - pinch harmonics and artificial harmonics are killed and the sound becomes sterile very quickly. we can go some way toward a fix by forcing the system to favour a specific harmonic overtone, but this then becomes the sterile note with no overtones or complexity.

You just don't get the shimmer and excitement of a real loud guitar tone from the sustainer as it is currently - with or without AGC, single or dual driver etc. - it just isn't a raw rock'n'roll vibe. sure it can fool you for a while, and can work very well in a mix, but for hours of playing it gets old pretty fast once the novelty has worn off.

When you think carefully and in detail about how real loud amp feedback works, you realise that there are many differences. The main one is that the pressure waves in a room work on the whole string and on the body and neck. It's easy and natural to 'catch a wave' by standing in the right place and positioning the guitar, then moving around as you play to maximize the energy of the air in the room to your advantage - just not an option with the sustainer as is.

I would like to think that there will be some way to get around this issue, I just don't have a working solution yet.

One possibility might be to introduce some sort of variable complex delay with reflections that provides a similar reverbation type effect as a room. I briefly looked into this a few months ago, but the PIC chips I could find that were affordable didn't have the processing power or bit depth to make it an attractive proposition. Might be worth experimenting using pc software to check if it would actually work, although having said that, the latency would have to be really low, and there's still the issue of driving only one point on the string but with a big mess of inputs.

All the ideas I've had about using esoteric types of string sensing are problematic due to extra hardware getting in the way of playing, or because they require precision of construction that would be beyond any DIY project.

anyway, still thinking away here :D

Col

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OK, some I'm understanding the whole kink thing. I need to process it for a bit.

I am ordering a cheapo Squier strat as a guinea pig guitar tomorrow as well. I have been wondering if my full size JB might be a negative in any way. Might there be phase issues also arising from signal induced and mixed by the separate coils in a fullsize bridge HB?

I would like to think that there will be some way to get around this issue, I just don't have a working solution yet.

Might cabinet emulation in the circuit be worthwhile? Has anyone tried sending any effects from a DSP unit to the driver?

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Yes...i agree...i kind of see where you are getting at...

Feedback from a room can be more complex and an exciting if more complex art to achieve. You can produce complex soundscapes with feedback and the interplay with the room spaces and such...on the otherhand, you can get very sustainer like responses, sometimes like santana uses, by staying still in a controlled environment...but I take your point.

Also...the pinch harmonics is an interesting and instructive phenomenon. It can be used as a unique "sustainer" effect...harmonics that resolve down to the fundamental for instance. Yes, a properly working sustainer will take a pinched harmonic and bring it back down, driving the string in most incidences. Although, natural harmonics can often be used and sustained in fundamental mode. switching between modes can also produce interesting effects. It is possible to sustain a note, switch to harmonic mode and create a bloom or transition to the harmonic...then switch back to fundamental and achieve an even higher harmonic from that...I am sure if held long enough the note may then resolve back down....but these things do/can occur. The "mixed mode" that I favour for the harmonic, where the bass strings always bloom, usually to a fifth above (usually produced with these 386 circuits with the 100uF cap) has more character to my ears.

It is different again from the full range of effects that feedback can produce...but in my mind I am building a sustainer, not a feedback replicator. My romantic view of it is an alternative way of exciting the string, much like a bow is to a violin...in this pursuit, I don't expect it to sound like a plucked string or feedback.

It's interesting too, and I feel the same way...

it just isn't a raw rock'n'roll vibe. sure it can fool you for a while, and can work very well in a mix, but for hours of playing it gets old pretty fast once the novelty has worn off.

But...the novelty of a concert of purely feedback guitar wears off too!

There are things that need to be pursued in this project, and individual tastes for sure. As I recall col, it was important in your work, not only to be as clean and fizz free as possible, but to keep that fundamental and control gain and drive...more so perhaps than I was emphasizing. In addition to this appeared to be the desire to attain different modes of operation...so perhaps control and variety.

Can we have both, I guess is the point that I was working towards here...control and variety...I think yes, but perhaps something different from the plucked string or something necessarily "guitaristic"...

That being said, I love the guitar for what it is...with this sustainer stuff, it is possibly keep in mind that the guitar is already as it already stands...a wonderfully expressive tool. Some of my favorite guitar sounds are incredibly percussive for instance...i have a soft spot for surf music for instance...hardly sustainer material!

In fact, if i were to embark on a further project, it would maybe be to add back the percussive potentials of acoustic guitar into the electric guitar sound...there are projects in progress along those lines. So...the sustainer is not the be all and end all, but a wonderful tool...

but each may have their own view of the destination to which we might be seeking I suppose...

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I am ordering a cheapo Squier strat as a guinea pig guitar tomorrow as well.

We are getting serious! Below is my "guinea pig strat"...hehehehe

testguitar1.jpg

It actually plays very well...but i needed something urgently a year or go in relation to a project in collaboration with a US builder. I took off the scratchplate and made a thin MDF disposable wiring thing...I can install pots and get to everything in the layout exactly like the guitar it is intended for...then the whole lot can be transplanted out of this into another guitar. Great, not just for the sustainer project but all kinds of wiring and other things...such a guitar is probably worth more than any other "test equipment"

Mine has a big bath tub route...I use double sided foam tape and spacers and such to attach pickups screwed to bits of 3mm MDF of any type, in any position and all without taking the strings off at all. I did plan on mounting a small breadboard on there too...but I found this to be a bit impractical, but others might find it a useful approach.

It is a good idea to do initial tests with just a single bridge pickup to avoid conflicts with bypassing and such...then you can try and add back in more pickups and more complex stuff. It would be an ideal platform to try some of the effects signal variations of your next question. You could add an effects chain into the signal going into the driver circuit (don't use effects on the driver signal after the circuit!)....

...

Way back, and somewhat controversial was an idea that I raised about the potential "organic synthesis"...or something like that...lol!!!! I thought that the use of signal modifiers may have a significant future role in what the sustainer concept would become. That after achieving sustain, adding filters and distortions of various kinds...especially time based and pitch shifting kinds of things may produce very interesting and unique sounds.

However, I was perhaps a little over enthusiastic, I am not sure it would be really possible to really get a guitar string to vibrate with the characteristics of a violin bow or the texture of a sax...it is a string after all. However it is an interesting thing to explore if not actually giving quite what you may want from it. I guess though, in some ways I was influenced by the idea as proposed and demonstrated by ebow users that can exploit EMI effects and change location of the driver and pickup at will and make some passable imitations of such instruments (although, with a lot of work and additional effects that they down play). In fact, the ebow is "best used with the neck pickup" is often overlooked even as the sustainer is seen to be limited by it's use only with the bridge pickup.

So yes...I was doing things with flangers and such from before page one. I continued for a while and intended to continue further with it, part of the early motivation was to play with the phase issues...flangers and such of course work with delays and pitch shifting that might be advantageous, I also have an old tycobrahe pedal flanger that allows good manual sweeps. Things like limiter/compressors can make interesting preamps. Cabinet simulators may be interesting too in subtle ways.

Although some of these things are interesting, are they really that practical. Also, I know that you can get the basic sustainer working very well and constantly improving. The concern for the phase things may be more theoretical or motivated by the lack of performance of your first attempt. Before getting things more complex, you really need to get the basic sustain thing to work without things like the distortions and poor signal response that you describe...no amount of tricky circuitry will fix these things if really. Some of these EMI problems...overpowering and distortions and especially installation and bypass failures...can cause massive problems with string response and getting a clean sound.

....

Some other uses for a test guitar might be to explore a bridge driver with a neck pickup...the reverse of the usual arrangement. There is some sporadic interest in such things (I was contacted only recently about it) and may make an interesting instrument, perhaps combined with a bridge piezo or something.

I have had sustainers working with many types of pickups...including the JB. The biggest problems I have had are with traditional cheap telecasters. Generally, I have found HB's better and some commercial systems require it, or even to use their bridge pickup with them. One reason I feel is that single coils often contain a lot of noise, and this noise is being amplified and put back at the string...much of it at high frequencies that are not useful for sustain but very bad for EMI and particularly oscillation issues. At the very least, noise in the system can cause inefficiencies that need to be addressed. However, it has worked with cheap old single coil pups, so the project can be forgiving and you could add input filters to help with this high frequency noise.

pete

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It actually plays very well...but i needed something urgently a year or go in relation to a project in collaboration with a US builder. I took off the scratchplate and made a thin MDF disposable wiring thing...

Uh oh! Did I hear the word "MDF"?

I'm glad you have finally given in and found the real tone wood Pete haha.

(Note to everyone: do not try to build an MDF guitar :D )

Edited by mrjstudios
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OK...I got a confession...

for some months I have not been playing much guitar...a little if any with the sustainer (even though this is on my main electric now!)

However...the sustain got a little damage and stopped working...the very fine teflon wire had come adrift from the driver...so I hadn't heard it in a while. So, breaking a string last night, I got up today, changed the battery and string and soldered the wire back on...

Having not heard it for a while, I wondered if some of the skepticisim wasn't warranted...but playing it again today, I think I was selling it short...

perhaps if people would like to hear some particular "effects" or responses I could work out a way of recording those things specifically.

I am getting polyphonic sustain (ie...more than one string vibrating)...it is working in lower levels of drive (with AGC) very cleanly and evenly...I am getting strong harmonics on all strings up to the 21st fret. Pinch harmonics will drop as col describes, but natural harmonics and such sustain and switching to a harmonic from that harmonic will go even higher (interestingly, switching back will give the fundumental or a mixed harmonic)...there have even been some tones that appear to be sustain both the harmonic and the fundumental from a single note (though more difficult to achieve).

It is in short working better than I remembered and although the sustained note after the initial plucking effects are kind of different, I wouldn't consider them boring and use of things like the drive control, vibrato and other ways of affecting the string is enough to cause interest...the delay also helps as I previously described.

Anyway...if it would be instructive to see where things can get to with my approach...and encourage others to aim for a similar response, I am prepared to attempt to oblige!~

pete

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OK...just to test some thing out...I found a cheap ($10) plastic mic, put it in front of my amp (fender deluxe, plus AD100 delay) and recorded a two track demo and added it to the sound click page...

basically, just a bit of noodling and sustainer effects...but gives you a bit of an idea about range, sound and response...but hardly a definitive demo...

Beware of your ears though...as there seemed some doubt about the ability to get high string response and harmonics up there...some of these sounds could be ear shatteringly high! The high notes are up around the very highest frets. I also turned it off and on a couple of times, mostly harmonic mode, mostly highset drive, but I think I turned it down a bit in some places. My circuit aims to get the control that col was going for, plus the non agc sound that I generally use...so you might hear some difference. Lower levels of drive tend to sound a bit flutey perhaps.

Anyway...let me know if that is of any help evaluating things or if you want me to try something specific...

play sustainer demo 01

The above link should take you directly there...I hope...if not, it was added to my soundclick page whcih can be found with the older demos via the link "with sound" in red in my signature!

pete

edit...no, the link didn't work so replaced it with the link to page, just press play on the first track there and it will play!

Edited by psw
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Very cool clip Pete!

Always good to hear these things in action.

On a similar front, I have just finished building a new sustainer circuit from scratch (the schematic I posted a little while ago). I used the new layout that I designed too, which can also be found a few pages back. It's just a matter of getting 1 more capacitor and installing it into my already sustainer equiped guitar to finish it. My drivers are largely, if not totally based on Pete's designs, and have been heavily influenced by his guidence along the way as I have built them. So if the new circuit design proves functional, (which I think someone has already verified), then I will be able to contribute another test subject proving the thin driver design's concept.

Once the thing works, I will also be able to record as many demo's as desired and some video as well. No, you won't learn anything new from them if you have read the thread, and you won't finally 'see the magical components' (because they don't exist)... BUT sometimes it helps people to hear and see things, rather than just read about them. Also, I'd like to get plenty of samples up just for the sheer purpose of having an audio and visual record of what great things have been accomplished here. I know not everyone has a recording studio or even a decent video camera, so I hope I can be of service in that aspect. Hopefully others will be sucessful with their builds as well, and also post videos and audio, making a kind of reference database of what can be done using for example "PSW's the thin driver design, and a 386 based circuit", etc. etc.

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Thanks MRJ...and it will be good to see how you go with the circuit and driver stuff...

The clip is fairly clean, but recorded with a cheap mic from and amp directly into the computer...the same sound is used for the riff guitar and the solo track but a different pickup selection. The bridge pickup is a full sized HB showing that this kind of thing works well. The driver is pretty much the specs of the original, 3mm deep with ceramic magnets below and a 3mm ordinary steel core...plenty of photos exist on the tele thread linked in the signature. It is of course potted in epoxy and pretty tightly wound, but it was hand wound effectively...

My circuit seems to work well, not too bad on the battery drain...but really it has no phase compensation, very little agc, if any at full drive...I would expect that very similar results can be obtained with a decent preamp/amp design...it does use the LM386 as other chips failed to impress me. The things of note in the design is the very compact layout and superior tantalum caps and stuff...a lot of that to save space really...unfortunately adds to the cost considerably however. But I swear, there is very little mojo in there...just a lot of care and trial and error testing of the design.

Anyway...the amp sound is clean and warm, plenty clean enough to play chords as you can hear...but there is a bit of grit on there. I don't think there is too much "fizz"...however, the string driven hard does have a distinctive timbre to it...it no longer sounds like a plucked string. A lot of the notes are not picked at all...I did try a bit of pinched harmonics...but on this guitar without distortion they are a bit clucky...so you don't really get the effect that col was talking about.

It is a bit better than older versions...better circuit design and such helps...but partly the efficiency was increased and the power dropped to improve things. The original strat had a lot of preamp gain that made the fizz issues worse.

It is hard to really demonstrate what people may be interested in...but I can try. In this new clip though you can hear how it can sound like traditional feedback, yet at other times it can be quite different...I am sure you can hear the string driven sound...I tried to play a bit that showed howthe feedback can 'evolve' with things like vibrato and trem use and not be too boring.

One of the problems with the sustainer is that it encourages long notes...hahahaha...so you tend to play slower or more for effect perhaps...I don't know, you can only do what we do...I haven't played electric in months so...always rusty...but playing fast doesn't really show anything, it sounds like the guitar it is on! The harmonics generation can be useful...and sometimes the reverse harmonic effect can be a very effective thing. I forgot to do any natural harmonics showing how they sustain without falling...there is some playing with the drive and harmonic switch while holding notes as I recall.

My design and ideas are not the be all and end all by any means...but they have shown to work. Unfortunately for tinkerers, some of the parameters are necessary...but then the principle is fairly forgiving. A lot have people have attempted to go their own way, but with things like wire gauge it has been pretty consistent in the results for this design. Now, a completely different design, perhaps the specs and assumptions need to be completely reassessed. In my rail design, I used 0.2mm wire...but perhaps with all those extra windings and the design, some other gauge would have been more effective. You see that the design itself may not be at fault but the materials.

I will try and take some picks of my bilateral internal magnet experiments...these were interesting...but unfortunately failed to drive in the mid position on the tele without a lot of EMI and squeal...so has been abandoned.

Anyway...I hope the clip is constructive, or instructive...or whatever. If this isn't the result other's are getting, it is not the design or things like tricky circuitry that's holding it back IMHO and I'd encourage more work or details for advice if people are struggling...

pete

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My first creation - no, not a sustainer, but an individual hex string driver winder.

Bits needed include an old DC cooling fan, a 10mm drill keyless chuck, a little Pulse Width Modulation Circuit to control the motor speed (a cct based around a 555 timer - http://freecircuitdiagram.com/2009/02/01/p...ontrol-circuit/ ), a reed relay (as a rev counter) & this guy's pickup winder program... http://pickups.myonlinesite.com/programs.php , a rod to support & allow tensioning of the wire - Oh yeah, and lots of hot glue....

workshopjd8.th.jpg (sure, it looks ugly ...but it's very functional!)

workshop2js9.th.jpg

speedyo3.th.jpg

The above 'proof of concept' PWM motor speed controller mash up, has now been migrated to a somewhat more permanent stripboard! Also the pot you see will be going in a volume footpedal, to allow me to control the motor speed with my foot.

Total cost - just £3.00 (for the keyless chuck) most of the other stuff, I had lying around (John Noakes would be very proud)

I've nicked a mini thread bobbin from my missus's sewing machine kit (she'll not be happy, but needs must!) along with a small bit of 5mm diameter mild steel rod....ready to roll soon!

What does everyone else use to wind their drivers?

Edited by Hank McSpank
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Man after my own heart...hope the wife doesn't know you're raiding the sewing machine for parts...

My recommendation for the thin coil and most single or dual coil drivers is to avoid using a machine...for a number of reasons. Mainly though, we are looking at less that 200 turns of a decently thick wire on a very thin bobbin...usually hand winding is better...and with glue potting there is a risk of spraying glue everywhere! Also, ten minutes tops to wind a coil...so by the time you have set up a machine, you would already have finished...ideally you'd only make one as well!

However, I can appreciate with 6 drivers to make for the prototype alone you may want to get automated. You workbench is a lot tidier than mine after all this time.

I have never had too much luck with the breadboard...maybe I am doing it wrong, I think col uses them (I actually own two)...but there can be problems with noise and stuff. Generally I have tended to make things on stripboard, with testing I tend to make a circuit expanded in layout so that I can add components into a general design. I use the fabulous DIY Layout creator to work out stuff and post circuits...there is a tutorial on this project on there to which I donated wire in appreciation of the circuit...nice pics.

Generally, some people who have not been content with this advice have come a cropper and abandoned their machines in frustration. The driver winder tutorial clearly shows a driver being built by hand and the latest tele driver was wound by hand as the epoxy was mixed but the cordless drills battery decied to fail under tension at the last moment would you believe!

...

I made a machine to manufacture the ultra thin 1mm coils...there was no other way to create them...it's powered by a cordless drill.

I also have a u beaut diy pickup winder that in typical style went too far...hahahha...it has 4 digit electronic up down and auto stop counter and powered from a sewing machine, the left and right spindals are made from a small bench grinder (so it's quite heavy) and has an aborted auto transverser and tension devices. designed2wind is a great website if you are looking for ideas there (fellow melbournite!). A unique feature of this is that it has a 4 digit tacho...it has been clocked well over 2000rpm...however speed is not recommended in pickup winding...heat and wire stretch is a big problem...lol

...

Some of the early hex things I used an old hand film winder I found...not the greatest, but it kind of worked. The later ones I was able to modify electronic components avoiding coil winding completely...this news was greeted with a hail of flames and accusations...it wasn't so great, a lot harder than winding the tiny coils and more expensive, but they were smaller...I needed to use a magnifying glass to dissect the bloody things...hehhe

But, I am wary that people might get distracted by machines instead of just getting to work winding a coil carefully by hand and underway with traditional coils.

Glad to see the cold is eased up enough to tinker...down here we have come out of a heat wave into a massive cold drop....shocking stuff...plus the fires have been shrouding the city in smoke.

Anyway...good to see some decent efforts there...maybe you can tempt me into making some more of these things...

pete

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Anyway...I hope the clip is constructive, or instructive...or whatever. If this isn't the result other's are getting, it is not the design or things like tricky circuitry that's holding it back IMHO and I'd encourage more work or details for advice if people are struggling...

I think that if you're going to say things like that, you have to make it VERY clear that you are using circuitry that you have kept secret and that these clips were not achieved using a Fetzer/ruby based system.

If I were new to this project I would be extremely suspicious that someone was implying that circuitry is not crucial, but at the same time refusing to post a schematic for their circuit. If its a legal issue, then wire up your driver to an existing public domain circuit (e.g. Fetzer/Ruby) and then post clips made with that, at least then, you're not giving the Fetzer/Ruby users false hope :D

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I think that if you're going to say things like that, you have to make it VERY clear that you are using circuitry that you have kept secret and that these clips were not achieved using a Fetzer/ruby based system.

OK...let me say it again...I have never used the F/R circuit. The first and main reason is that I was doing this a long time before Gmike did the tutorial that introduced the F/R here. There are other reasons too...no easy access to J201's, the design is not optimized for the project (hence my modifications to bring it up to my/data sheet specs) and the preamp biasing trim a PITA. The fetzer was designed for a "fender tube like distortion" something that I did not feel was advantageous in later years (though gain and distortion was clearly a feature of my earlier circuits). I also have not been very impressed by the ROG things, and I did not feel it a good idea to rip off "their" designs either...this is not a ROG project!

I have no electronics training, just what I picked up and mainly for this project and wiring guitars. Most of the early stuff was modular...there is a kit for the LM386 amp called the CHAmp (cheap and handy amplifier) which basically the LM386 data sheet...along the way I substituted the output cap in this for a 100uF generally. This kit is commonly available around the world and I have discussed it before...it works out cheaper than the individual components often...was presented in the magazine, Silicon Chip years ago. I have very little experience with discrete transistors, but the sustainer strat and other experiments usually used the CHAmp companion, PreCHAmp kit with modifications...basically substituting the gain resistor for more gain.

From the post above...

My circuit seems to work well, not too bad on the battery drain...but really it has no phase compensation, very little agc, if any at full drive...I would expect that very similar results can be obtained with a decent preamp/amp design...it does use the LM386 as other chips failed to impress me. The things of note in the design is the very compact layout and superior tantalum caps and stuff...a lot of that to save space really...unfortunately adds to the cost considerably however. But I swear, there is very little mojo in there...just a lot of care and trial and error testing of the design.

In designing the new dedicated circuit...the fireDrive...I started with the LM386 and a buffer. So in fact, the preamp stage probably has less gain than the fetzer. My intention was to make two versions, the one I now use since last year with the AGC, and a knobbled version without for public consumption.

However, other than hooking compressor limiters and all kinds of effects as the preamp stages as experiments...all of the rest was LM386 circuits and various pure preamps. The prechamp is a push pull two transistor circuit with high and low end filtering (the circuit is published somewhere)...but I felt it was a bit big and over complicated for this project. Others used common opamps, particularly the TL071 family. Generally I keep an eye on common and easy to understand components.

I did try a bunch of alternatives to the LM386...many were discussed and I don't remember the numbers...but I couldn't match the performance of a properly set up LM386. Here are a few pics of various abandoned circuits...

Here is a typical TL071 preamp module I worked up...

amp3-1.jpg

This is the same one with a companion...I assume an LM386 design...

amppre1.jpg

Here is an interesting dual LM386 design...

dual386.jpg

This one was based on a design I found somewhere that used an LM386 individually for the +/- waves...I forget the details...

These pics were posted years back when there was a push to make things more modular.

Unfortunately none of these were any real improvement over what I was already using...and were so not recommended. The latest circuit is my own design, and intended for a product...the fireDrive and ultra thin coil designs.

If I were new to this project I would be extremely suspicious that someone was implying that circuitry is not crucial, but at the same time refusing to post a schematic for their circuit. If its a legal issue, then wire up your driver to an existing public domain circuit (e.g. Fetzer/Ruby) and then post clips made with that, at least then, you're not giving the Fetzer/Ruby users false hope

Well...I am not sure how to take that...hmmm...is that a complement of the performance of the sustainer in the clip :D It is not my intention to spead false hope, I was trying to address the skepticisim about the performance possible with the standard design. If people think that what I am saying is untrue, listen to the first clip played on the sustainer strat way back...4tune8

The second clip diablo is the one of dizzy's mid driver strat with phase compenstation and bilateral coil...nothing much was given of this though originally I did see a pic (but didn't save it)...I am lucky to have downloaded the clip. Although nothing I have tried myself has made the mid driver possible...this is perhaps the main carrot to suggest that it is...false hope? (listening to these old clips again, I was always quite keen on the flutey sounds of 'the yearning' and the celtic-esque 'airie'...'siren sea' is a primitive experiment in multitracking but uses some interesting effects such as a pichshifter to create an organ-like sound)

The main improvements I have made are in the driver and installation...and just spending a lot of years tinkering with this. I think the tele driver is the best yet (although the ultra thin has been promising but needs more testing I suspect)...but then this is very much back to the original 3mm coil design.

...

I don't think this is false hope...I don't think I have any reason to mislead people. Col, hank and Donovan as well as many others appear to know more about circuit design than I do and more adventurous in their approach...others along the way have been far more knowledgeable, LK had some great ideas.

My motivation is not to mislead...there is probably a touch of "what a clever boy is psw" given my fragile ego at the moment...however, I simply don't have the electronic chops to come up with anything so tricky! Further, the only reason for the thin coil concept was to avoid phase compensation and circuitry beyond my grasp...that is kind of the whole point of what I have been trying to achieve.

I wouldn't be spending so much time trying to get other people's projects up to scratch if I didn't know it could be done...nor be so vocal in my opinions to try and get people back on track and back to basics, if I didn't know there was more potential to be had from the basic design I created. It is my baby in many ways...I want to see it grow up and travel the world...not sick and ailing. (unfortunately in real life, I have lost that opportunity, so perhaps there is a lot of transference going on in that regard).

...

So...there was no way I could have faked this naked two track recording...it definitely sounds like a sustainer, right! It is getting towards the kind of performance I had set out to achieve...possibly the limits of the basic design without getting tricky. I'd be interested on some feedback on the clip and if this is the kind of thing that people are aiming at or trying to achieve. I am still set up to record more clips if you want to hear something specific in terms of performance characteristics. Perhaps some comment of fizz, the sustain sound compared to the natural sustain sound, comparisons with traditional feedback. I prefer this sound to the previous tele clip that was recorded direct, as this amp set up (not withstanding the cheap mic) is what I normally use...but hardly loud as it was recorded first thing sunday morning...hehehe)

Honestly...I think a lot of problems are from the well intentioned deviations to the design. Absolutely you should get very similar results to the 4tune8 clips with the F/R or any similar LM386 combination...these were all made years back with basic amps and PVA coils...in fact the very pickup driver in the pictorial.

I take your point, but as I have not made anything since the telecaster version, I don't really feel inclined right now to take a step back and do up a version with a lesser circuit. For now, the sustainer-strat should suffice to show that it worked all those years back. The main differences I think is that I can run the things at a lower power (cleaner sound, less fizz, better battery life and less EMI problems) due to better driver construction.

Others appear to be going in opposite directions, nothing wrong with that, unless it is motivated by the assumption that the original design doesn't work as described...or can't! So, I posted this clip, and will post others if you like...to demonstrate that without any phase control, the highest frets will sustain, fundamental or harmonic without any phase compensation...and the characteristics of the sustain given the discussion of plucked strings sound and such...and the level of "fizz". Other things I guess that clip doesn't demo is things like the characteristics of polyphonic sustain, or the harmonic drop. I suppose it doesn't show the sound with effects or distortion either.

Anyway, I thought and my intention was not to frustrate but encourage you guys...I'm sorry if that failed...I actually was quite impressed with the performance of the device, even if my playing is so rusty these days!

pete

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Hello all-

The lead in those clips shows very nice sustain, Pete. Nice work.

I think I understand what Col was getting at... just that your results may not be indicative of what us noobs can expect to get if you are not using the "standard circuit" shown here, even if you do not endorse said circuit. We need SOME circuit to use as a reference for expected results. Regardless, the past few pages of posts have prompted me to continue sitting, waiting, wishing... so something came to me, a test to try. Once it occured to me to try it, I felt like a dumba$$ for not having tried it before... testing the sustainer circuit sans the preamp and listen strictly through the wood. Is my thinking right that I should not care about loading the pickups if I am not connecting the guitar output to anything? Or would the loading still affect the loop in a negative manner? If not, then some testing last night convinced me that my driver needs work as the phase issues are still present, even sans pre-amp. Amp circuit is standard LM386 (but -N4) with only some extra power filtering in the form of bypass caps, which to my knowledge should not be the cause of any phase issues as it is not part of the signal chain.

This driver is a standard strat neck pickup, originally a Fender Tex-Mex custom staggered. The bobbin was blocked off with fiberglass strips at the top, leaving a 3 mm gap and wound with 0.2 mm polysol wire to 7.9 Ohms, potted with urethane and vacuum degassed. I was VERY careful in its construction. The pole magnests have been lowered flush with the top of the bobbin. The problem I believe at this point is relative to 2 items:

1) The stock pole magnets for 2 reasons...

A) although I have no evidence, I think I may need to remove these in favor of smaller, disc-shaped ones, such as the craft magnests I have heard mentioned here previously. I am thinking the extra length sticking out of the bottom of the driver is at least a potential issue for excess EMI and/or phase issues. I also am not entirely clear on optimizing magnet position in the Z axis. Should the magnets sit entirely below the coil, partly below, or span the entire depth? I am not sure if these are ceramic or AlNiCo magnets. Being as I do not care about ruining them, should I try cutting or filing/shaping them?

:D This pickups polepieces do not align directly beneath the strings, as if the pickup were designed for the bridge position or another guitar altogether. However, I know this did originate as a neck pickup as the stock bridge was a full-size HB. Also, the original middle pickup seems to be the same geometry. Is this common or did I get the wrong pickups stock?!?!?! I have a bunch of scrap ferrite strips used in transformer lamination. The pieces are small enough that I couls layer them to create a blade or fill in the holes between the pole pieces on the bobbin. Does anyone think I should attempt one or the other?

That was supposed to be a "B", not a stupis smily sunglasses guy... doh.

Edited by Donovan
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Well...I have done a ultra thin coil conversion on a staggered pole single coil traditional fender type. The staggering is not necessarily ideal for string response, but it will work.

Your driver sounds like it is perfectly capable of producing good results.

The loading will affect the sustainer on it's own, it is about input impedance, the LM386 poses a fair amount of resistance without some kind of buffer...so it's pushing up hill.

I know what Col is saying...and I know it may be frustrating...but I hope you can understand. I have tried putting up proposed circuits, but they have had mistakes...it is only when you design something, get the parts, build it, and test it that you can be sure of anything. Earlier circuits (pre layout creator) were never written down but kind of evolved on the boards.

To develop something up will take a lot of work and effort...I know what is in mine and there really is no phase control...even the AGC is pretty basic and preset, a lot of the time it is not even activated in the higher drive levels. It was fully my intention...then again, I thought others might have had a go. It would obviously be easier if I were to do something in collaboration with someone. If someone has some ideas for a basic opamp preamp (say a tl071, tl072) and LM386 kind of thing and puts it in layout creator...I could perhaps give it some psw touches and we could give it a try and fix this problem (and it is a problem) finally for a basic standard circuit.

I suspect the big influence on phase in mine may be the output cap...that's why it was changed to a lower 100uF over the more usual 220-420uFs (no secret there). This was to ensure good high string response...however, the lower strings tend to bloom to harmonics...something I quite like. A bigger output cap will give you better fundamentals on the lower strings, but then the highs wont be so good. A switching of caps may well be a mod people might like to try as an add on...I think we have discussed this before.

Ohhhh...that reminds me, I use 10-46 gauge strings. Sustainiac recommend these kinds of gauges, the sustainer will be struggling with skinny little strings. I haven't tried it, but I suspect the lighter strings may well work on the tele.

My very first experiments in fact used an lm386 and an output cap and nothing else but the battery! But, although it was kind of working (on a single string driver) the loading was a big problem.

Anyway...will leave it there for now...I have not been doing any electrical work lately, although I have all the parts for the proposed 12 clones of my exact circuits at hand. I was thinking of about $60 and a small amount of post...so that might be a bit of an option if you want to actually try exactly what I am using. I actually have trouble getting my hands on some of the components, some are specific SMDs...so even if I did consent to publishing the thing, you might find it hard to duplicate and probably more expensive than me building them anyway (at least in this first lot!).

pete

ps...i have suffered a bit of an "accident" a couple of days ago...I have a pretty bad head injury, stiches and can't wash the blood out of my hair for a few more days...I don't know if the blow will help any...hmmm

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Hope you are doing ok Pete!...

Well I finished installing my new circuit in my sustainer test guitar.

Circuit: works great. (as far as I can tell -- I'll hook it up to a speaker to see just how clean it is). I had none of the biasing problems people have had in the past with the F/R type circuits. In fact, it took me about 3 seconds to have the thing right at 4.56 volts (perfect), where in the past I had to fight with it to get it anywhere near the 'clean' operating range, and even had to carefully select batteries. Also, everything was much easier to wire up and get to with the new layout. SO... the new design and my layout is definitely a step up from the stock F/R.

Driver: at some point the driver got banged around a little bit, and it seems to have let loose and now the internal windings are vibrating :D

I did have working sustain with this driver in the past, without any huge problems (the problems were in the circuit), but now something has gone awry internally, and it is oscillating so bad you can hear pitches coming from the driver itself (not good at all).

So with this major setback, I'll either have to resurect my trusty first driver, which I was lucky enought to have work well the first time, or I'll have to rewind my current strat pickup turned driver. (Note: the first driver is the blade design which can be seen on my youtube video from so long ago)

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Is it a PVA driver? It could be rewound and taped again perhaps...but I wonder if this is really the problem so much.

Excessive EMI effects and internal vibration maybe a result of too much power perhaps...the balancing act again...can you get that gain way down...especially the pins 1 and 8 gain control (this might clean things up a bit).

Maybe the new circuit is too good...hahahha

I don't know about the F/R thing...I have not liked it for my own reasons nor tried it...but I know people like primal had immediate success with it...and it seems others have too. I certainly think people could come up with better...more recently I have been wondering it needs any preamp gain at all...maybe a modded ruby kind of thing would be good. Especially with any decent output bridge pickup like an HB.

Also, the biasing of the transistor is only necessary because the transistors are so unpredictable. While even LK (a discrete component fan) argued against opamps I think that something decent could be possible if only because it avoids this procedure and the space of the trimmer. Anyway...it is worth getting a couple of j201's or whatever you are using and find the one that best calibrates.

Shame about the driver...not sure how you can bang something like that up...was it potted while winding?

How about you test the resistance again, make sure nothing has shorted. Also, test a coil lead against the blade pole...it is important that the coil has not shorted against this. To be sure, I have shown in the pictorial how PVC tape was wrapped around it before winding. If there has been vibration around the core, the insulation may have rubbed off and grounded against it!

Pushed hard, I do recall the sustainer strat having a bit of internal vibration that you could slightly feel if touched lightly...but never enough that it would squeal...that one went through the wars and used for years extensively...it still works now!

pete

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It is a PVA driver, wound to your .2mm wire, 3mm cross section specs. It is wound around an old single coil pickup which has had it's bobbin blocked up leaving the 3mm at the top.

I'm gonna test everything, but I'm about 95% sure it is the driver. There is a definite point at which I can crank the circuit up to before it goes from driver winding oscillation to circuit screaming. Actually, the trim pot on the LM386 works pretty well. I was able to run at almost full gain there, and full gain coming from my preamp before the circuit went nuts, so it is MUCH more stable than a F/R.

I think what happened is that this particular driver isn't super tight. I vaguely remember when I made it that my clamps holding the sides in while it dried weren't super good... but I figured it would be fine with all of the PVA glue potting it. And it did work for a while, but I think after it took a fall, and the leads got twisted and pulled a bit, the very inner windings must have let loose. So there must have been a slight air gap in the potting... I hate it when that happens. :D

It isn't grounded to the core either... the plasic pickup bobbin is still intact and protecting from that. The windings may be shorted though...

Oh well, back to square one. I know I can reuse the driver itself -- I'll just need to rewind it. And I'll test the circuit with a little speaker to hear how clear I can get the ever dismissed Fetzer type valve :D

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Well...i think it will work...good to see we are getting twards a proper run with the thing...and the mods seem to be working ok. I know it has worked for quite a few people over the years...or so they have told me...some have done it without even joining in here...and just emailed a thanks...so I have top presume it all worked out ok!

A benefit of the PVA thin is that is can be rewound easily...just cut it out of there. Tight is better of course, but the sides are always a bit looser on a long coil and need to be pushed in, taped up and clamped for a bit. So...amybe you are right about it after all...there is only so much gaps PVA can fill...and if they come loose, they wont glue back or anything.

This is why it is worth being prepared to make a couple of drivers...it isn't what people do everyday, getting it right first time is not always going to be likely, few can always do a bit better with some practice and some mistakes to learn from. Preparation is important too...have the tape cut to 3mm widths for instance to wrap around it before clamping and the glue will not squeeze out as much and be held tight when released.

The one in the pictorial was kind of a clone of a stand alone driver I had made the week before...the bobbin on the prototype was cardboard...still around here and works. In fact...I used it to test the old sustainer box idea on the les paul...and it had a steel core...but I could just stick different types of magnets to it...that's how I found out that flipping the magnet also created the harmonic effect...go figure.

The harmonic thing was a happy accident in fact...i think at first all i got was harmonics...i switched the wires...and it worked properly...obviously all it needed then was a phase switch. Since of course, I found out that this is pretty much already been discovered...isn't that always the way!

keep working on it...the F/R may still have some life in it yet!

pete

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...I know what is in mine and there really is no phase control...even the AGC is pretty basic and preset, a lot of the time it is not even activated in the higher drive levels. It was fully my intention...then again, I thought others might have had a go.

Just because there is not intentional 'phase control' doesn't mean that the phase response of your amp will be the same as or anything like that of the F/R.

Each stage of the circuit - input buffer/pre-amp, any filters, the AGC and the output cap could alter the phase response. Your amp could be 50º, 60º or more different over import parts of the guitar range when compared to the F/R or other circuits - there's no way of knowing without measuring or simulating it.

Just because your unaware of whats happening doesn't mean it's not happening or that its not good :D

If it is doing something nice at some sort of 'sweet spot' it would be good to analyse it and find out WHY then use that knowledge to create of improve some standard circuit.

Or just demonstrate that its bog standard and it really is all about the driver !

I suspect the big influence on phase in mine may be the output cap...that's why it was changed to a lower 100uF over the more usual 220-420uFs (no secret there). This was to ensure good high string response...however, the lower strings tend to bloom to harmonics...something I quite like. A bigger output cap will give you better fundamentals on the lower strings, but then the highs wont be so good. A switching of caps may well be a mod people might like to try as an add on...I think we have discussed this before.

A bigger cap (220u or 470u) should not effect the higher frequencies, it should just give a more transparent low end. If a bigger cap really does have a negative impact on the high end then there must be some other reason.

In other news, I've been working on a simple circuit (fewer than 20 components) that might be a nice beginner option, but at this stage, i don't have all the parts to go for a test run (super low value resistors aren't easy to find locally). When (if) I do, and if it works, I'll post it for others to try.

cheers

Col

Edited by col
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In other news, I've been working on a simple circuit (fewer than 20 components) that might be a nice beginner option, but at this stage, i don't have all the parts to go for a test run (super low value resistors aren't easy to find locally). When (if) I do, and if it works, I'll post it for others to try.

Cool....this is good news...and if MRJ can get good results as well, that will "fix" the F/R to something more stable perhaps...along with stribs cool little circuit (an op amp design and apparently working well) is yet another option.

The reality is, while I started the thread and am the main contributor...it is still a collective effort with various branches along the way. I am not responsible for developing circuits for other people.

I am glad if people are impressed...if indeed they are...by the performance of my guitar as in the recent clip. If people would prefer to believe that there is some secret mojo involved, or I hit upon a lucky accident...then I will stop protesting this. You are right, as far as I know, there is nothing particularly special about the circuit, but what would I know.

People can choose to believe this, it is not what I believe. The reason for this is that I have been doing this for a lot of years beginning with little to no electronic experience other than basic guitar wiring things...certainly not circuit design. I have tried to learn what I can with potted research and a bit of practical experimentation. The facts are that I was getting results with any number of different circuits. Mainly the poweramps have been LM386 based, as they are extremely easy and cheap for this kind of battery application. I did try to replace the chip, but had poor results. I did use different output caps, but found in most cases the 100uF gave me the sound that I liked...other caps certainly worked, higher values like 220uF giving a better bass fundamental.

Make of this as you will...but there is years of photographic evidence to show that I have been using all kinds of preamps from 4 knob limiter/compressors and stomp boxes, running into the LM386 circuits ti just the lm386 and an output cap on it's own. Audio evidence has been very difficult till recent years.

I am proud of my more recent circuit, but only because it is neat compact and carries very high quality components...making it more difficult and costly than the F/R. I am certainly less skilled than many of you appear to be, and I am sure that given a few months of work, perhaps an even better circuit could be devised...who knows...how clever really does it need to be?

...

What I might like to here is whether the kind of effect that the clip showed, or that people might like to hear from it...is the kind of thing that people are shooting for.

I played it for some people the other night, and they were very impressed...but playing a "performance" over just mucking around for myself heightens your awareness of how it comes across as a musical tool. If there was something that might improve things, it may be that it tends to go a little too far. It has a tendency to continue to get ever louder, something the AGC was intended to correct, but it is pretty mild at high drive levels, if working at all, and maybe I should have tried to make it more adjustable or something. Basically, the longer the sustain, the harder the string is being driven, and that is not always appropriate, and not that subtle. I guess a compressor on the signal could control things to a more even keel, but then you would loose some of the dynamics!

The thing that disturbs me most about the potential for me to make a product of this is that it isn't perfect, and every install seems to be a bit different and I can see people having problems and I would feel responsible. I already carry this burden, hence my time here trying to help...but if I were selling something, that burden might be a little too great!

One of the "defects" in all of my devices has been the off click. The tele suffers the least of any, and substantial work went into trying the different bypass switching things. The tele will give off a pop at turn off...but interestingly, it only does this if you attempt to turn it off while there is no sound from the guitar. Turning the device off when it is playing a note is silent. In fact...it is kind of cool...turning the thing off doesn't change the strings vibration at the time (the pop is not masked by the guitar, it is simply not there) so that if it is playing a harmonic for instance, the harmonic will continue to ring on. It's not as on/off as an effect box or anything.

The switching on multiple pickup guitars seems to be difficult as well...since my proposed "commercial" fireDrive product, for which I created the present circuit design is designed for strats, this poses a bit of a problem...hmmmm

...

I understand how and why people are thinking about the hex things and worrying about the phase things...look at the first ten pages of this thread to see how much I obsessed about these things. I realize that frustration may be making people feel that I must have some secret of great importance that I am not letting on...maybe there is something I am not aware of, but it must have been something other than this circuit because it was there from at least the sustainer strat on. As it stands, now and at no time have i made any profit from this...in fact quite the opposite. Given the nature of the guitar gear industry, if I intended to it would probably be better if I exploited this notion that I have something secret. What I have is something well designed and tested.

Now the intention was that I make a scaled down version of this one as a circuit design, but with all that has happened, I don't feel any urgent need to spend weeks designing and testing a design that I personally have no use for. I am perfectly happy to collaborate as I can, and as I have done with MRJ to improve the F/R.

There may even be something in it for me/us if more was done with opamps in the preamp stage...I think there could be some options there to explore like filters and limiting that the discrete designs are not so well suited to that such a design may lend itself to. Perhaps the closest to this was stribs design, my only reservation with this was the difficulty (I have) of obtaining the poweramp chip. However, the CHAmp or data sheet LM386 circuit could no doubt replace it if people had a mind to.

On the project as a whole...The more neglected part still seems to be the installation and switching elements. More of interest to me in recent times. Especially in relation to multi pickup guitars and standard instruments...low mod and ease of use and clear instructions that works in most cases being paramount.

On the subject of "non-disclosure"...people have their own various reasons, and it has been consistent over the years...in not revealing all that they have been doing. This has made it hard to help people for lack of info, pics and audio. I recall someone adding a diode clipping circuit into the preamp...basically a fuzz box...with the theory that this signal would be better...lots of EMI later it was revealed, removed...and the thing worked. Confirming the theory that as clean a signal is most likely the better approach....and that a basic preamp/amp will work. Similarly with drivers, magnets and all kinds of things out of my control.

In an honestly "secret" project a year ago with a custom builder...I built all the electronics here on my test guitar (the reason I bought it) exactly as it would be on the real thing. The intention was that, being so far away, it could be dropped straight in. It was also the first full ultra thin coil implementation of the fireDrive.

Upon receipt...everything worked but the sustainer...and the neck pickup. This pickup was custom made by seymour duncan and built by his son in the custom shop...the driver was fitted by the builder without their knowledge. The assumption was that my driver had caused the fault in the pickup and was in fact not working at all. Extremely embarrassing for a week or so. However...the problem was eventually discovered...SDjnr had forgotten to magnetize the pole...there was no magnetism at all!!!! Once magnetized...instant perfect pickup and sustain. But not before we did a bunch of fiddling with the wires on the assumption that I had done something wrong or it had come adrift.

Now...this was only one "transaction" with a competent professional custom builder on a very high end guitar...this was enough to make me realize what I would be opening myself up to with a commercial system that had any elements out of my control and for which I might be liable form 3,000 miles or more away to fix...a little off putting. I am even concerned about building my present circuit (because I can't vouch for others building and parts) and selling it for cost (in fact a loss with time and posting and such) for fear that people can't make a driver to realize the performance.

In fact...the ultra thin coil was an attempt to create a bobbinless, coreless coil that experimenters could use in their own designs or pickup conversions (still a possiblity)...this stems from the work with tim/onelastgoodbye way back as some may recall. The reason, that if it didn't work, at least I knew what was being used!

...

OK...here is a thought...if I were to put in the time and effort...design build and test a circuit...how many would be prepared to by a kit of parts from me with instructions? I don't know how much it would cost...possibly no more than getting the parts yourselves. Would people purchase wire if I were to wind it on to something perhaps?

In all honesty, it take me at least a decent amount of time to develop something like this, not a little cost over the thousands I have no doubt invested in my personal work, test it and organize money and post...but other than a financial motivation (which I have never gained from so far) I can't think of any particular motivation. As sensitive as I am (especially with 20 stitches of so in the head at the moment), I don't think proving my point down here is enough for me to do it...at least on my own.

I am not even sure if I did it, that everyone would believe it anyway...who is to say I didn't use some exotic magnet, or the guitar is special, or my pickup is different. The next thing you know, I will be asked to install piezos to prove it will work with them, or single coils, or complex wirings!

I would have hoped that the audio would have provided some hope and support in what I have been trying to say...or at least give a benchmark or something. Oddly, I was kind of expecting that there would be criticism of the sound or the fizz or other factors...or requests to post something without a backing, sustain a chord...am I to assume that the clip is what people might have expected it to sound like, or is it not what people would want from a sustaining device? With all the talk of plucking strings and un-guitar-like string driving...I thought people might point to a mark in the clip and say..."see here, that's what I am taking about..." because, I have not yet been convinced by the concerns. I understand them, I acknowledge some of the truth in them, I have empathy for the perceived need and the doubt...I can even hear some of it in the device, it is far from "perfect"...but it is good, and it does all that I ever claimed it would...for me.

Or just demonstrate that its bog standard and it really is all about the driver !

Now...I am very keen to help others get the same, similar, different...or better results. But call me lazy, I just don't have the motivation at present to get back into the practical work...and coercion through misplaced guilt is not going to do it for me at this time. Again, if someone will collaborate, we can exchange files on DIY layout creator, someone can build it...I might even and test it on my drivers...and the problem (clearly not a problem for me) of a standard public domain circuit can be solved...at least for now!

pete

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With all this talk...I thought I'd go back in time...and over a hundred pages...this is where col came in with a new circuit and new idea and skills...and just after primal completed his LP with F/R sustainer successfully...

Anyhow all this sustainer stuff came back to my mind - I started to wonder if an electro magnetic sustainer could replace that missing something that you get with loud volume. So I googled "DIY guitar sustainer" and here I am hehe.

After one abortive attempt, I have constructed a working driver - its not perfect, but good enough to experiment with. I used some 6mmx2mm iron bar that i got from B&Q. The coil is 2mm deep with about 135 turns of .23 wire for about 7.5ohms. I made the driver core too long, it overlaps the strings a bit too far... also the bobbin wasn't quite wide enough so even getting it up to 7.5 ohm was a struggle - epoxy all over the place :-| fortunately i bought a pack of disposable latex gloves for protection.

My next one will be better :D

The main thing I've been working on is some circuit ideas.

After breadboarding it, I figured that the Fetzer/Ruby isn't quite right - I couldn't get the fet to bias correctly. Not sure if this is because its a cludge of two circuits that were not designed to go together... or if I just messed it up. Anyhow, after some messing about with different input stages, i've settled on an op-amp based pair of unity gain buffers - one feeds the sustainer amp, the other is the guitar output - I Hope this setup will prevent any 'loading' that often happens when a guitar signal is divided between 2 amps without buffering.

I'm having the usual issues with the top E string - it struggles on the first 6 or so frets, but improves higher up the neck. To get the high E going I had to turn up the gain so much that the A and G strings were much too 'lively'. Tweaking the output cap can help fix this, but it messes up the response of the low E and A...

So I figured some sort of compression/Auto gain control(AGC) might help.

After lots of web research, I have tried two approaches, a preamp with loads of gain that clips all input to about the same level, and a non-clipping AGC based on an LM13700 chip. So far, the Auto gain control approach seems much better. The guitar responds in a more natural way - more the effect I was hoping for, similar to being in a room with an amp turned up loud B). The balance accross the strings is much better, so the LM386 doesn't have to be dimed ( i disconnected pins 1 and 8 and use an attenuator on the input to set the level ! What this means is that the thing draws much less current so the battery should last longer. My initial measurements are between 30 and 70 mA, so a 9v alkaline should last in the region of 10 hours (I'd be happy with that, so I hope its correct B)).

The downside of the LM13700 is that its fairly chunky, and with that, the buffer op-amp and the LM386, along with ~30 smaller bits and pieces, the circuit won't be so compact. Theres enough room in my axe, but maybe not some others.

I still want to mess about with some combinations of filters to tweak the Phase and frequency response to control the Harmonic effects - I find the 180º phase trick to be a bit extreme, but some level of harmonic bloom is very nice - it would be good to have control over that with a knob on the front of the guitar - maybe a push pull job that doubles as an on/off switch.

Fwiw I'll post a schematic when i'm happy with it. Hopefully, someone with better electronics skills than me can then take it and iron out all the noobie errors

I've noticed some potential alternatives out there - lots of different multi-function ICs exist, the most promising I have found so far is the LA4160 which is a combined pre-amp, AGC, poweramp that has phase compensation and on/off click protection... it seems to be available in a traditional DIP package (i've not tried tackling surface mount components yet so DIP is good). and it's "cheap as chips". If someone can hack together a circuit with it, it could be very promising.

here's the datasheet for it

Anyway thats enough from me...

cheers,

Col

As new people can see...col came straight in with some preliminary success with the basic design (or close enough) ...so click on the little pink arrow in the above quote to go back to 2006 :D

Now...I don't know if a better driver might have been more success...if the wire was a little too over spec...I did notice...

I'm having the usual issues with the top E string - it struggles on the first 6 or so frets, but improves higher up the neck. To get the high E going I had to turn up the gain so much that the A and G strings were much too 'lively'. Tweaking the output cap can help fix this, but it messes up the response of the low E and A...

Well...I guess I have the same problem too...my solution is the 100uF cap, which produces a harmonic bloom on the lower strings (that I quite like) and better high string control. I've suggested that perhaps a switchable output cap might be another approach...maybe a frequency dependent switchable output cap if we wanted to get tricky with it!

I looked this up because this is kind of how I recalled it...what followed was a substantial movement towards dual coil and bilateral designs....and, col presented his own remarkable circuit. Col contributed greatly to the next step in drivers and circuits that I held a lot of promise...there were others to like curtisA that came along at a similar time and people may well be interested in going back to this part of the thread with the current interests and ideas.

Now...I don't know if more couldn't be had from the thin driver and the F/R combination had it been worked further. By this account it did appear to work and it could have worked better...in fact I think it would sound something not unlike mine. This is exactly the kind of thing I would have thought that supports the notion that the F/R or similar non-loading amp circuits will work. I suspect, that with a second attempt with a 0.2mm instead of 0.23 wire and a shorter bobbin...perhaps a touch thicker than 2mm deep and it might have worked better still...who knows, maybe the PVA method would have allowed for a tighter more consistent winding. Clearly, it wasn't exactly duplicating the design I presented, but pretty close and it did in fact work!

But, you are right in that the response and sound that I was and am getting isn't what everyone might want...I'd like better, especially a little less of the runaway effect, maybe with the next design.

I did some experiments with dual coil designs...both the rail and bilateral designs...and of course the old hex stuff. I think they will give a different response to the single coils but they are a valid idea worth exploring. For practical reasons on the guitars I use and the results I have been getting, I just kept returning to the original.

But...I think that this kind of indicates strongly that the F/R will work and that the driver is at least as important as the circuit to the working of the design. I also feel that it wasn't given a chance to completely live up to it's potential...but that was a choice to move in different direction...fair enough.

I guess that is why I am feeling a little perplexed and defensive about suspicions of deception of how the sounds on that clip were made given this history and others that have had results, all of which support what I have been able to achieve and am currently getting.

Having eventually gotten hold of a sustainiac for a bit...I know that something more like col was after is possible and the direction that he was going was very much moving towards the sustainiac and fernandes solutions (as per the patent descriptions and designs).

However...there are things about the response of my greatly simplified version that I like better...and I think things like the pickup/driver potential was a good one. I'd like to see a dual coil HB converstion pickup driver (maybe built into a cover) and this was what I intended for the next stage on the ultra thin strat pickup conversion kit. Definitely I would like to see more work and solutions to installations.

The hex things, I am not so sure about...originally I had hoped for a sustainer bridge with the driver miniaturized and built just ahead of the saddles...but now I suspect that would never be possible. I did try numerous "acoustic" versions like the model C hoping to shake the strat tremolo enough to cause sustain...but I found EMI and mechanical losses to great for that to be likely either. I experimented with some piezo kinds of things...but they just don't have the mechanical movement to shake the strings from the bridge.

This gives people some idea of what I have tried and hoped for and perhaps where I am coming from. There is still plenty of scope to take things further or in different directions...but I know that the thin driver design works for whatever reason with numerous basic circuits and I believe ample evidence is there to back it up. For the moment, all practical work by me has ceased...I do intend to do there dozen circuits though if people want to try them...we'll see if this encourages me to do drivers perhaps as well.

My more recent projects have been in piezo stuff and I had some assorted ideas for controls...some are being explored in this LP I am doing (no sustainer). Originally I ws going to make pickups...but with so many people doing this, I would need to find a special niche I suspect. I had been thinking that perhaps an alternative active pickup to the EMG's might have a place...so perhaps one day. The way the economy is going though, these kinds of luxuries will be the first things to suffer I guess...

Anyway...hope I'm not insulting or boring people in these meanderings, whoever comes up with a basic easy standard circuit will no doubt find their place in the history of this thread I am sure...and relieve a lot of frustration by many, including myself!

pete

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Pete, have you ever tried a sustainer device as following:

A driver with an iron core built into the guitar. No magnet is being used so this way it will not work at all.

But now if we put/place a magnet above the driver there will be a magnetic field and the sustainer will work. (I hope)

It could be a small but strong magnet in some way attached to the picking hand to achieve some interactiveness (what col wants).

By moving the magnet the magnet field would change (weaker, stronger, different strings). And it's cannot be that difficult to come up with a construction to mount a bar magnet above the driver. (In order to have the old functionality back)

So we end up with the strings in between driver and bar magnet.

Just an idea of mine. Please evaluate! :D

Fizz

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