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TheEnigmist

Homemade Sustainer

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Hi all, i'm new here! I'm looking for some ideas, schematics and other infos about how to develop a sustainer. What i've is:

  • Ibanez s870fm
  • Old INF PU
  • DiMarzio Evo 2 Bridge PU + DiMarzio Evo Neck PU

I want to do tests on old PU (so i won't destry my new PU) and my goal is to use Strib's Schematics with an humbucker PU as drive and the opportunity to use that drive as a PU when Sustainer is off. It is possible to achieve this idea?

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Yep.

Sadly, Pete passed a short time ago. Still, his polarising thread has a LOT of very important information on sustainer designs. An interesting legacy for those of us who were there through all of the arguments and fallouts they all caused!

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I wouldn't think there would be a need for a humbucker version I know they where some test using a coil and a pickup side by side that fit a humbucker mount but you couldn't sustain while using that pickup there was just too much feedback

 

The humbucker pickup was developed to solve a problem as a motor I think it would cause problems

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6 hours ago, TheEnigmist said:

Well, it is a lot 190 pages! I read some of them and i saw only single coils used. Someone can say me at what pages i can find tests on humbucker system?

I'm not sure a working humbucker-size driver was ever developed in the big Sustainer thread. I think member 'Col' attempted to build one, but I'm not sure it went very far.

There is a lot of chatter, hypothesising and distractions going on in that thread (part of the reason it was eventually closed down), so sorting out the useful information from the noise is quite difficult.

The basic DIY system consisted of a coil of wire wound around a metallic core. I think it was 200 turns of 0.2mm enamel copper wire. The driver amp was just a glorified transistor radio speaker driver based on the ancient LM386 chip. Some people got good results based on this formula, many people didn't. I built one that worked, but it was very temperamental. The simple circuit and construction method meant that anyone could have a go at building one, but not everyone shared the same degree of success. Many ideas were thrown around to try and combat the deficiencies in the basic design (poor note selectivity, feedback between driver and pickups, high amounts of interference and noise etc), but to my knowledge there wasn't an awful lot of success.

If you're a practical kind of person I'd say have a go at building one - they're a lot of fun in use - but be prepared for it not to work as well as a genuine Fernandes Sustainer.

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      HI!, i'm new in here, from uruguay. i'm in that same path that seems a lot of us is (was)... Diy sustainer!. 
 

    Searching a lot on the internet, found the famous pete thread (and read a lot of it), but some other stuff too.

    So first there's the amp: everybody talks about the Fetzer/Ruby amp. so looking for that the most realiable thing i found was this: https://www.youtube.com/watch?v=md5aHzoegYs

    Now, that work only with 3 strings, the thinnest ones, on the thread the problem seems that there's not enough power for the six strings,

 so looking for that i found this: https://diysustainer.wordpress.com/dualcoil/

   I couldn't understand much, but it seems that the solution was to make 2 coils that move 3 strings each, instead of making an amp he bought a kemo amplifier: https://www.kemo-electronic.de/en/Light-Sound/Amplifier-Splitter/Modules/M031N-Amplifier-3-5-W-universal.php

  that amp works from 4 to 16 ohm, so he made the coils disregarding of the impedance thanks to that amp.

  i want to make the amp: on the thread i found this picture: 

 

that sistainer picture was drawn by pete, he says that works but he couldn't test it, on the other hand, he says he make a circuit without the lm386 chip that works but never showed it.

 

 looking for other circuits i found this: https://www.youtube.com/watch?v=xXB92cSQi8E

that guy says he made a completely different circuit that did not need the lm386 and also did not need that the coil be of 8 ohm (which accordingly to pete was a must).

 

 So: i'm gonna try to build this schematic that pete left and see what happens.

 first with 1 coil, and if that doesn't work, with 2 coils in one for 3 string each coil.

i'm hoping that (maybe this) thread becomes the new sustainer thread (or making a new one), so we can have a (maybe) more organized way of making this work.

 

Sorry if my english is not perfect.

if anyone has any ideas or thoughts on this matter please share. Thanks all for all the info.

 

 

 

MRJSUST2a.jpg

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On 12/29/2016 at 3:37 PM, Peyton said:

I couldn't understand much, but it seems that the solution was to make 2 coils that move 3 strings each

From what I gather he's treating the driver as a split system, in the same way a two-way speaker uses a woofer to reproduce bass sounds and a tweeter for the treble. Each driver covers three strings and is fed a portion of the input signal tailored to the frequency range of each group of three strings. But he's not changing the construction of each driver to be more efficient at bass and treble ranges, so it's unclear whether this will have much of an impact on the scheme.

Nearly every DIY sustainer I've seen has always been a variation on the Fetzer-Ruby schematic. The Kemo amp just substitutes the LM386 for something with more grunt. A bigger hammer to drive the nail in, so to speak.

As good as PSWs intentions were, he lacked the technical understanding to fully explain why he did things the way he did, preferring to simply stab in the dark until something worked, and then advising people to reproduce his method to get the same results. In reality the Fetzer-Ruby (and derivatives) is woefully inadequate for the task, building the driver coil gave inconsistent results for everyone and no real work was ever put into addressing the shortfalls of the whole system. The added distraction was that PSW would tend to go off on wild tangents and long-winded posts that further clouded the development of the sustainer - too much talk, not enough action.

Most people who were interested in building their own sustainer simply wanted a verified, known-good set of instructions for building the driver coil, and a schematic for the associated circuitry that would at least give predictable results in most circumstances. PSWs idea was to encourage experimentation using the basic 8ohm coil and Fetzer-Ruby schematic as a starting point. It was inevitable that the disparity between the two ideals would lead to poor results and frustration for many.

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I've not heard it put any better by anybody. Pete's work on his sustainers certainly never ended in a simple single end product, and perhaps that was why so many people fell out over the whole thing? That they weren't willing to put in the groundwork on their own systems, and simply took the inherent shortcomings of a consistently-evolving project as being a fundamental issue?

If anything, I'm on the side of where Pete was at with this, in that raising people's consciousness as to how things work and applying that to one's own specifications (white box design) is better than simply offering an inscrutable "it is what it is" black box design with zero explanation, documentation or development potential.

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Possibly the biggest hurdle to overcome was having a base design that worked for everyone. The unfortunate thing about PSWs work was that over the duration of nearly 7 years that the monster thread ran, the best and only recommendations was the F-R circuit and the 8 ohm driver, both very much guerilla solutions.

I did actually chat with Pete privately via email a few times. He was a quite a nice chap away from the hussle and bustle of the various message boards he was participating in, but very much an 'ideas man'.

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Thanks the answers guys:

 about the split coil:  The two coils are reverse wound to each other and they run into the same amplifier BUT between the + of the higher strings coil and the Kemo, there has to be a 220uF Capacitor. The Capacitor lets through only the higher frequencies and therefore this coil becomes optimized for the high strings.

  that's what he did.

  About PSW's it was not mi intention to criticise him in any way, i started this sustainer quest just recently and that thread it's the biggest and with more information in the entire web.

Now i'm not an electronics guy, so i'm more on the side of having a little bit more of the work done. For example if the 386 it's not the best amp for this task, what should i use? 

 Thinking about it, the amp it's just to make the coil move the strings, so technically any amp with enough power low comsumption and low distortion could do it.....   right?

 So, for me it's making the fetzer/ruby or been in the complete dark, about the coil, of course there must be a relationship between the copper wire size, impedance of the coil and the strenght the coil has over the strings, but again i'm in the dark.

 If anyone can help me understand this things it would be much appreciated. in 2017 i will start studying an electronics course so in time everything gets easier.

Thanks for the replys once again and sorry for my bad english.

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8 hours ago, Peyton said:

 about the split coil:

...

  that's what he did.

Yep. He's also wound the two driver coils in opposite phase. This is mentioned in at least one patent on the subject of sustainers as a means of cancelling the emitted magnetic field of the driver to minimise the effect of induced noise in adjacent pickups

 

8 hours ago, Peyton said:

Now i'm not an electronics guy, so i'm more on the side of having a little bit more of the work done. For example if the 386 it's not the best amp for this task, what should i use? 

 Thinking about it, the amp it's just to make the coil move the strings, so technically any amp with enough power low comsumption and low distortion could do it.....   right?

Yes, although technology has moved on a long way from the LM386. I suspect it was originally used by PSW as it was easy for him to get cheaply and didn't require much electronics knowledge to get it working on a 9V battery. The fact that nearly every design he proposed was pretty much lifted off the LM386 datasheet (the Fetzer Ruby too) suggests as much. There are far better ways of doing it now. The fact that none of the commerical sustainers use (or ever used) the LM386 should be the first indicator that it was never the best solution. The Ebow is the only exception, and all the DIY sustainers based on the same circuitry performed no better than this.

 

8 hours ago, Peyton said:

of course there must be a relationship between the copper wire size, impedance of the coil and the strenght the coil has over the strings, but again i'm in the dark.

There must be, and I'm surprised that after all that time the defacto 'standard' by PSW was always 0.2mm enamel copper wire, 8 ohms impedance, wound as shallow as possible (3-4mm high was typical IIRC). None of the commercial offerings use this format and I refuse to believe that their R&D somehow overlooked coils of similar spec to PSWs. Magnetic circuit theory dictates that more turns of wire will give a stronger electromagnetic field, which goes hand in hand with creating an efficient driver, particularly when operating from an amp running on a battery where long running time is important. I wouldn't be surprised if the Fernandes and Sustainiac units are more like 100-300 ohms impedance, particularly seeing as the driver also doubles as the neck pickup when the sustainer is switched off.

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I genuinely wish that my electronics experience and education had been maintained and grown. Years back, I might have far more to add to this development than I can probably offer right now.

My gut feeling is that voltage is preferable to current? A higher coil resistance run at higher volts and fewer amps seems like a preference in my head. If I were actively developing my own sustainer, I would consider a dual-battery 18v circuit (possibly -9v/+9v) as opposed to a single 9v. @curtisa can probably confirm that I am somewhat obsessive with using an 18v potential.

Designing the coil is going to be black magic that I haven't got the right tools to tackle on anything but the most basic level. Coil depth or thickness might not be the same direct relationship as with a pickup, and certainly, AC is a different beast to a basic DC solenoid.

It's quite apparent that an 8Ω coil is a ridiculously low resistance for any sort of a driver. A proper sledgehammer/nut example if I ever saw one. The same magnetic field should be able to be produced by a less-hungry more-resistive coil. After all, pickups produce output a fraction of that from a battery supply and at far higher impedances. Sure, a string doesn't pour all of its energy into deflecting the magnetic field when vibrating, so a driver needs to push back harder than a string-pickup relationship. I'm not saying anything new here.

So which is preferable for a coil? Thicker or thinner gauges? For example, a larger/longer/thinner-gauged 1kΩ coil or a smaller/shorter/thicker-gauged coil of the same resistance? Obviously at the extremes the difference is not useful information, however is there a sweet spot? Are we talking gauges similar to those of pickups or thicker such as those found in the field windings of motor commutators?

The last example might be a useful one; after all a motor is electricity used to induce movement...

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OK, so I stand corrected - I just dug out some of my old notes on the subject and found a bunch of photos that somebody took of an autopsy of an old Sustainiac Stealth driver. The two coils measure 6.2 ohms each, each coil connected in parallel. That would indicate each coil is likely 8 ohms AC impedance. In parallel that's 4 ohms. So the implication is that current (brute force) is more important in getting the strings moving.

There's nothing super-interesting about the construction of the driver, other than it's physically taller than PSWs (about the same as any single coil pickup), uses two laminated cores rather than a single solid core and probably uses thicker wire wound more times. Note also that the Sustainiac Stealth has since been replaced by the Sustainiac Pro (no idea what the differences are), and I have never seen details on the Fernandes driver.

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Wow, that genuinely surprises me. That would imply a very poor battery life on these units - was that ever part of the deal?

This is totally why I've never wanted to wade deeply into these waters....my understanding is so scant, out of date and un-exercised that I'm unsure on what I could offer.

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Sustainiac claim 20-50 hours of operation from a single 9V alkaline battery in thier FAQ. Note that's not running time, merely if you forget to switch the unit off. It could be less if you want to use the thing properly.

Their other claim for improving battery life is to redesign the driver amp to use "a digital power amplifier that was four (4!) times as efficient as a conventional power amplifier". What they're really trying to say is that they've dispensed with linear power amps (LM386 and others similar chips) and used a class D switching device instead to maximise battery life. The same technology that is utilised in just about any small format audio device that runs on batteries these days.

Really, this is one of the key areas where the DIY sustainer should have made inroads. The trouble is that many DIY-ers wanting to try this out were hamstrung either by the fact that building a class D amp using off the shelf components increases the complexity beyond what they were willing or able to do, or having to resort to a  self-contained class D chip amp which 99% of the time are only offered in ultra-tiny surface mount packages, again making it difficult for the bedroom builder to put together. The LM386 option persists because it's easy, not because it's the best.

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