Sustainer Ideas

[col]

(oops double post - can't find a delete post buttong either?)

Space_ryson....tks for ID'ing Q8/9 ...I'm not familair with that variant. Also, since this is a push/pull power amp, I'd have expected the transistors to have had slightly different numbers? (one will be a PNP...eg MJE172 & the other NPN such as a MJE182)

Although it might be a 'quasi-complementary' push pull output, in which case the main output transistors could be identical.

cheers

Col

[psw]

Class-D amps use push-pull output stages - e.g. there's one in the sustainiac patent circuit.

True...but very efficient controlled ones, not me hacking a pair of transistors to an output stage!

alternatively, they could dip in to anywhere in the last two thirds of the thread - 99% of the pages have repetitions of extensive summaries of the project

True, but someone (and this has happened before) posted a request for tutorial on a DIY sustainer recently. If you watch the stats and the member viewing lists, this thread above all others almost always has a guest, sometimes up to eight "guests" viewing it. I am often contacted by email rather than post here, in fact some have even completed it successfully without any assistance from the information here, though this is rare. I also know of numerous people in other forums and here that read this thread like a blog, they are just interested in what's going on. This has had some unusual, flattering and disturbing side effects on yours truly and others who contribute. There have been many attempts to persuade me to take it elsewhere for profit (although none for me, mainly google add revenue I imagine)...there have also been various attempts to replicate it as well...in at least one case that I know of, stealing the information of contributors and representing it as their own.

In the past week or two there have been perhaps 2,000 hits. Unfortunately, what they are seeing may not be what they were expecting and generally I try and keep those people in mind... Part of my concern is that when a new era of experimental work (which is good) takes a lot of pages, people tell me they feel shut out...others feel like for all this type-fest, the thing is complicated and gone nowhere...which of course isn't true. Others have expectations far beyond what the title I gave it specifically suggests (I must have had a good day when I wrote that out!)...

Anyway...just a little insight to some of the behind the scenes of this thread that I "administer"...I have actually made some close friends through this all over the world...along with a few, well, we can't all be 'friends'

when you tried these alternatives, where did you get the circuits from - were they existing tested designs, or your own designs (or heavy modifiacations)?

Well, I don't have formal qualifications in electronics or anything. I have a reasonable grasp on principles, a lot has been learned along the way. For a while I was quite obsessive about it....I bought a lot of textbooks (a couple of feet of them) and had a bit of background in effects as well. But it is a "potted knowledge" at best I guess. My degree was in music, my post grad in information services.

So...I also "discovered the internet right here and PG was the first forum that I ever joined. I discovered it while researching some projects.

With the dual LM386 I think may have come from "headwize" which does small headphone amp circuits. I'd browse circuit design sites for anything that might be useful. It is hard to not keep coming back to LM386 type circuits for these kinds of battery applications. A lot of it is from data sheets. The better circuits for the LM386 are quite specific and I tend to give the LM386 as much 'help' as possible from these or variations that I find.

Data sheets are generally the first point of call...application notes where possible. There are lots of sites that explain opamps and their various uses. I have always struggled a little with discrete (transistor) circuits, probably a lack of confidence that I can keep them happy (won't go into oscillation for instance, or some weird distortion)...although as time goes on I can see the patterns in the circuits.

To that, I add experience, mainly with this application...so my choice of a 100uF output cap on the LM386 was trial and error mostly...I like the response generally (though lately I have been contemplating a switchable output cap perhaps for a possible project if I am not forced to move from my house in the near future).

I also have developed my own kind of layout "style", I guess. I am looking towards as compact a circuit as I can get but still make sense. I almost exclusively use stripboard for this. I have tried but find computer inputs of diagrams far to time consuming over pencil and paper sketches...that makes "simulations" impossible. I have also been burned by posting proposed circuits that have errors in them that would be sorted with building.

On a "new" circuit idea, generally I will build it in a modular form. If I am using the LM386 I have a number of them built as modules on their own. So, I might make a preamp on a separate board and see how that works. With a more completed design, I might space out a proposed layout and leave the legs long on crucial components (gain set resistors, caps) so they can be swapped out. I have a few breadboards, but they have always frustrated me.

Banckia's DIY Layout creator came at a good time for me, I did use stripboard magic (full of bugs and clunky) previously. SBM did auto layouts from a drawn circuit but it taught me how bad that can be compared to what "I" think makes more sense (far to many jumpers across tracks). I look at it more like a printed circuit board I suppose, I don't mind track cuts and jumpers to make it neater or more compact in the end. There are a few general rules I guess about power and ground rails...if you work with op amps there are recurring themes and "looks" to these kinds of circuits.

My personal aims for this have been leaning towards simple and small. Here are a few examples of some circuits I experimented with...

The first one is a dual LM386 design, very low parts count and compact layout (searching for more headroom and using it in BTL to avoid a direct driver to ground connection to see if that helped), the next two are an LM386 "CHAmp like circuit and an opamp preamp module. On the back you can see they start to get a bit messy...sometimes I might add test components to the underside. These are prototypes, if they are promising with the mods, I will rebuild them again with those incorporated into them.

I also have a test guitar or so and some known working drivers and circuits of various kinds. So, I can test a new driver on a known circuit or a new circuit on a known working driver. I also have generally kept a test guitar...my latest is a strat that allows any pickups and circuits to be installed and played around with...

Not just for sustainers...but a really good workbench...plays well too! The pickups can come in and out without string removal and any amount of switching a circuits can be installed or taped to the guitar. I always test with the guitar through a small practice amp. The sustainer strat was the previous guinea pig I suppose...wore it out though!

Amp circuits are always tested through a small speaker. In developing AGC things, I could swap out components or use trim pots and actually hear the circuit cutting or "beating" and with the input a real guitar, I can hear what it is doing with a "real world input" and input loads. Testing it with the driver comes next.

So...very much tinkering, probably very inefficient way of going about things...but there is some method to it...relies a bit on intuition and experience more than knowledge and hard data. It's not that I am "against it" but I lack confidence in the interpretation of these things in my hands anyway.

...

oops, overly long post...but some may be interested in the methods and the amount of care, attention and testing I do put in to these things.

Electronic switching is used also because it is cheaper and more compact - it doesn't make sense to have a massive wadge of expensive custom switching hardware when some cheap and compact off-the-shelf switches and a few tiny very cheap transistors will do a better job.

Well...I know this is not strictly true. I have seen sustainiacs elaborate delayed switching circuits to avoid popping and effective bypassing, more switching power required. Even then, the rose uses a 4pdt switch like I do, the fernandes at least a 3pdt to turn it on as you can see.

Perhaps people disagree or don't have the experience that I and the commercial units obviously experience, I have for some time been wanting help in this area. I have tried a bunch of solid state switching chips, but they become quite large and involved and far more involved and space consumptive than even a 4pdt mechanical switch. Getting into digital switching opens up a hole new can of worms for me, more than I can put the effort into and creating larger circuits than the extremely compact things I use now.

Given the need for switching and for an accessible battery (hard enough to find in most guitars) a very compact circuit that I can actually create is important to my aims. A sustainiac or fernandes circuit is perhaps five times the size of mine and nowhere near as adaptable (especially the fernades with the on board switching).

I have also tried a bunch of sockets including using IC socket strips...but I have generally settled for hard wiring colour coded ribbon cable in recent times...more compact and far more reliable...I have 10 wires coming from my tiny circuit...adding connectors would greatly increase cost and size and you can't get them through the tunnels on a lot of instruments anyway.

...

Drivers are a whole different area. I have actually had a wealth of experience in making stuff as a hobby or small business. I have been an art bookbinder and won a few awards...some of these skills have come in very handy as it happens.

Making a new driver design can take for ever. Recent ones I have had to construct machines, but any of them will require quite a few jigs. More adventurous designs take an enormous amount of thought, collecting and fabricating materials....

Possibly over confident on this one...but all the same, some things will only work if they are done well. In this case the elusive mid-driver. Perhaps over did it, but you can imagine how much time that took to do. We know that the standard "thin coil" design will not be enough to work so there is no point following that road if you want to do this kind of thing. I was a little less aesthetic conscious on my more recent bilateral things. But, I have always enjoyed trying to make the things look good I guess. The hex things were even harder to create...especially as they got more and more compact and often required up to 12 tiny magnets in them.

I also had a thing for them lighting up for a while...seemed to divide peoples opinions. When I first started doing that, I was accused by a couple of people as faking it (we couldn't post audio back then) and that I was trying to sustain the strings with the LED's

Mostly these things are hand made and can take quite some time to create even when I am just replicating things. The ultra thin coil was aiming to rectify this to an extent...months went into them, much of it before I knew if they would even work! These coils have no bobbins or cores, I was/am hoping that this design could be used in a number of ways either as piggyback things or stand alone drivers and the aim was to have adjustable bobbins to create different kinds for things like dual coil ideas.

...

Along the way there have been a lot of different aims or ideals, lots of different paths followed to get near those goals. All of them are compromises. The hex things hold some promise, but at a substantial cost...a lot of electronics, large circuits, specialized instruments and inventive manufacture. The invariably outstrip your DIYer's abilities. My ultra thing coils for instance are totally impractical for people to build...however the tele style 3mm coil could easily be hand wound with a bit of care and practice.

...

Ok...more than enough, must have been having withdrawals. Unfortunately, I can't easily post links as last year my firefox update decided to erase all my bookmarks. The computer itself is post marriage, the other computers are pretty old and decrepit (this ones not too good either) and are windows 95 and 98 machines and not worth firing up.

There are an overdose of circuits out there, but the principle is the same. I imagine that a lot of people are far more "knowledgable" than I about the specifics of circuit designs to get more adventurous if they choose too...I have tried to go the other way to work out the simplest way of achieving the effect and practically use the thing with as little modification as I can get away with on fairly standard instruments.

But the sustainer is only one thing, making a guitar (or at least assembling one) and setting it up is probably more important than anything you could do electronically...the sustainer is a neat effect, but it is secondary to what the guitar can do without it. The sustainer though can be very expressive, but like anything, relies a lot on technique...some of it specific to playing with a sustainer, to get the most out of it.

pete

[Hank McSpank]

Good post.

I also had a thing for them lighting up for a while...seemed to divide peoples opinions. When I first started doing that, I was accused by a couple of people as faking it (we couldn't post audio back then) and that I was trying to sustain the strings with the LED's

I can say quite categorically here & now (& without any sense of embarrsment or shame!)...if I *ever* do get a hex driver working, then without a shadow doubt there will be six LEDs aboard the final driver. design..you can *never* have enough guitar bling!

Edited March 31, 2009 by Hank McSpank

[psw]

The most I could ever get in there was 5...between the strings and drivers

These miniture drivers would also self destruct from heat...you will notice that a lot of them were built into aluminium casings (press molded by hand in this case from flashing material) and held together by various mixtures of things like iron and epoxy for both magnetic shielding and to hold them all together.

This one is about 5mmx5mm in section, the wiring done with Teflon coated winding wire, twisted and then heat shrunk.

...

You may be able to see how these kinds of designs led to the thin coil design when I finally got around to doing this...these kinds of hex things were not really a practical solution to present as a DIY project and quite expensive and time consuming to build given the results I was able to achieve. Still, I think I may have been testing with fundamental errors, I didn't use any bypassing in those days for instance.

pete

[space_ryerson]

space, could you go to the final frontier & clarify which schematic you posted a couple of pages back please?

It's the Floyd Rose sustainer I don't know nearly as much about the Fernandes sustainer. After a lot of number crunching I *think* I've found a suitable transformer replacement, which I'll be ordering from Mouser tonight. This thread was a really informative read.

As for the part numbers I gave you earlier, I was only able to read Q9, and not Q8, due to how they are pressed together; but they looked identical.

Edited March 31, 2009 by space_ryerson

[col]

....

ERROR 137 "Post too long!" in module 182.12.5 of unit 5: community member 'Col'.

DUMPING Memory to file.

Please allow up to three days for reboot procedure.

If fault persists, replace unit.

Possible workaround: concise posting.

[AndrewCE]

So, i'm sure this was answered somewhere in the past 306 pages, but I can't find it: is it possible to just use a cheap guitar pickup as a driver?

[psw]

is it possible to just use a cheap guitar pickup as a driver?

Not really...there have been reports of such things but no proof...there are reasons for this. You can make a driver out of a cheap pickup...for an introduction see the links in my sig below.

If it were as simple as that, you know that every guitar with a pickup would be doing it .

...

Col...

Sorry...couldn't be concise at 1am...however, you may find some interesting circuit here...http://www.headwize.com/projects/...couldn't find the dual LM386 circuit....perhaps it was somewhere else, perhaps ROG have something similar

pete

[Hank McSpank]

So, i'm sure this was answered somewhere in the past 306 pages, but I can't find it: is it possible to just use a cheap guitar pickup as a driver?

There are likely two main reasons why you can't...

1. Pickup wire is incredibly thin...0.063mm (42 AWG) - this size of wire just won't be able to handle much in the way of current (& current is what we need here!)

2. On a normal pickup, the wire is wrapped around the pickup's bobbin too many times.... more windings = more inductance (which makes it hard for the circuit to pump out the high frequencies at high enough drive).

I've just 'parked' my CNC project until the weekend - if you're interested, here's where I'm up to.... http://img12.imageshack.us/img12/365/cnch.jpg (it ,might not look much, but that's a solid 1.5 days work there! ...it just needs the motors mounted & I'm ready to roll) Relevance to sustainers? ....*very* easy to make an acrylic bobbin at the drop of a hat!

....so, I can do some more driver/circuit tests in the next night or two!

As it goes, late tonight I used some 0.063mm wire as my latest 'test' single string driver . It's wound onto a small nail...impossibly small (8.2 ohm). It's like winding with Nicole Kidmans hair! It now just needs potting (not that there's much to pot) & therefore it'll ready to 'burn baby, burn' tomorrow night

I'm expecting this driver to go 'poof' at the slightest hint of a bit of current, therefore i'll be setting the VCC on the power amp very low (at about 4.5V) & feeding the power amp a very low signal! (I just want to prove my 'less turn is good' for the high B & E Strings)

Edited April 1, 2009 by Hank McSpank

[psw]

Nice work on the CNC machine. I tried to make a 2d manual table router about that size but it didn't work out...CNC, I wouldn't get through the programming!

The Ultra thin coil jigs are made from PTFE I think...they take days from me to make before I can even make the bobbinless coil...hahaha

...

I suspect there are a balance of forces using very thin wire and low turns, it's going to have a lot of resistance to current and as you try and force it through a lot of efficiency will be lost in heat perhaps. There is also the problem of the difficulty in generating enough EMF with such coils. It is possible though to heatsink the cores or coils in order to stop self destruction...often this seemed to be a requirement to even test similar things that I was trying.

There may also be an issue with how close to the strings you will need to get the driver...there needs to be adequate space to allow string vibration...some hex designs that I made lacked "projection" I found.

...

You may consider using an amp that can take a lower impedance driver...an LM386 can run drivers of 4 ohms, not much good for a single driver...but perhaps these kinds of things it might be an idea to use a thicker wire and less winds.

pete

[Hank McSpank]

I suspect there are a balance of forces using very thin wire and low turns, it's going to have a lot of resistance to current and as you try and force it through a lot of efficiency will be lost in heat perhaps.

...

pete

From my RAF days (some 28 years ago - so admittedly not exactly fresh in my mind!), all things being equal (8 ohms of 0.063mm wire vs 8 ohms of 0.2mm) the current through the driver coil is not related to the wire size, the current through the coil is more to do with the no of windings (inductance) in combination with the VCC of the power amp.

So with my .063mm wire, again all things being equal, there'll actually be less resistance to current (lower windings, less inductance = less impedance)...but nevertheless, this thinner wire will struggle when I crank up the VCC (which will increase the AC voltage signal applied across the driver & therefore current through the driver).

Re the EMF...once again, as far as I can tell, that not related to the wire diameter...but more how much current you can push through the coil...again this wire being incredibly thin, probably means not a lot, before it starts melting.

You may consider using an amp that can take a lower impedance driver...an LM386 can run drivers of 4 ohms, not much good for a single driver...but perhaps these kinds of things it might be an idea to use a thicker wire and less winds.

My LM386 has been stamped on, covered in lighter fuel & set alight (in a Jimi Hendrex-esque manner) ...I have no wish to go back there! I suspect it'll be possible use the TDA7053A to driver a lowe impedance load than 8 ohms - this will be my next tack (eg using less windings of 0.15mm wire for a driver)

Edited April 1, 2009 by Hank McSpank

[psw]

OK...well. my technical nonclamature is not up to scratch , maybe col can make more sense of it. There does appear to be significant differences in the diameter of the wires to many facets of electromagnetic construction. Typically these are explained in terms of hose pipes and fluid flows for people like me.

I can say for instance that a coil of the same resistance in different wire guages can have a tremendous difference to performance, especially high string performance...both if it is too thin, or it is too thick. There appears to be a balance required for particular designs. Compensating by adding more power is almost always futile.

One thing I think you are on the right track with is aiming for lowest possible power. From that, I am assuming you are aiming for greatest efficiency and tailored for the strings and frequencies required. Very much what I was aiming for. For a first step, my hex designs were seeking to provide more effective drive from a mono source (no hex pickup) with drivers aimed at the various strings requirements.

As for amps...I realize that you have some bias against the LM386, I wasn't suggesting you should use it there are very many amp designs that can run a range of ohmages effectively and this might help. There were some amps in that headwize link earlier for instance that are low wattage but current driven for electrostatic speakers or other kinds of devices (a lot of headphones are actually 32 ohms, others are 4 ohms).

I do think that you judge the LM386 over harshly...it has been around for a long time because it is still very effective for a lot of applications. Unfortunately, most of the latest designs are SMD's and difficult to work with, source and expensive in their own way. The LM386 can be used effectively for this project though, features in the ebow and in the vast majority of successful DIY sustainers here for instance though it is not "the best" perhaps. I did find some faults for the application in the 7053, I am not entirely sure now what they are off the top of my head...I know i tried twice to implement this amp though...I even wondered whether there were problems with the BTL style with this project...but I'm not completely sure.

However, if you can find a suitable replacement, all the better. I guess in some ways I have been a little lazy in this regard. I tried a few alternatives, but I guess if you are working with something you know, cheap and easily obtainable...then there is no need to try too hard.

I'll try and find what the problem with the 7053 though. I do recall the chip heating up a lot, and indicator of power being wasted I suspect. Similar with drivers, if they are getting warm, there may well be a dramatic loss of efficiency

pete

[col]

So, i'm sure this was answered somewhere in the past 306 pages, but I can't find it: is it possible to just use a cheap guitar pickup as a driver?

There are likely two main reasons why you can't...

1. Pickup wire is incredibly thin...0.063mm (42 AWG) - this size of wire just won't be able to handle much in the way of current (& current is what we need here!)

although, if you double the number of turns, half the current will give same power of magnet.

2. On a normal pickup, the wire is wrapped around the pickup's bobbin too many times.... more windings = more inductance (which makes it hard for the circuit to pump out the high frequencies at high enough drive).

Yes, its the inductance that's the main issue here rather than the current handling for a guitar pickup.

I have wondered if it might be possible to make a small coil that sits next to a guitar pickup and acts as a transformer primary inducing a string driving current in a standard guitar pickup - a low inductance 'primary' wouldn't cause the same issues with frequency...

I wonder if this might be related to whats happening with Petes piggy-back drivers causing the squeal when the pickup is not disconnected at both ends - maybe its not something to be avoided, but something to be taken advantage of ?

Have to think some more about it...

cheers

Col

[psw]

Well...more work could be done I suppose. I have a feeling that the "piggyback" thing has taken on a form of denigration...the piggy back thing is only one way in which the thin coil design could be applied, an afterthought really. The exact same difficulties occur with the same design neck to a pickup as with the tele pickup.

You may also recall, I think it may have been curtisa that encouraged it back then, the notion of running the pickup (whether under or next to the driver) in combination with the pickup coil in parallel (causing very little change to the ohmage of the driver). This was shown to be quite effective, with some fiddling about. It did seem to complicate switching a little more in some aspects.

It should also be noted that, whether a "piggyback" installation or a separate driver in the neck position, the middle pickup also needs to be lifted and can't also be used in parallel...there is still interference with conventional simple driver systems for this kind of thing to be possible, jsut as the middle driver is not possible with this design.

The piggyback thing was really about adding the driver in a height adjustable manner without the loss or affecting the neck pickup or requiring routing or extra space for a driver on standard guitars, specifically the stratocaster types in my work.

...

But many of the decisions I have made in the directions I have followed are in pursuit of a range of factors, not necessarily the "best"...but the more practical, easiest, smallest, simplest, lowest mod...these kind of factors are important to what I have always aimed to do. It explains why I personally have resisted too much exploration of more complex designs (though I have presented any number of concepts of the time)...many of these require too many compromises to the native instrument. You may win these things back by using the driver as a pickup as sustainiac have done, but if the effect can be had easier and retain the passive pickup, that seems to be a better approach to my work.

But...the point is...the "piggyback" or a driver adjacent to the pickup makes no discernible difference to the issues involved. The problem with a lot of these things is that I seem to be a lone voice...very few people have even been doing this on multipickup guitars which has left me a little perplexed. CurtisA was using a strat but I believe he implemented my switching scheme...otherwise, I am struggling to think of another person who has even touched on the problems involved. This is always a problem as more people working on a problems will lead to more variation in approach.

pete

ps...it might also be worth noting that I have done the "piggyback" or compact drivers with a range of pickup types with success...from cheap ceramics, bladed ceramic, alnico pole and stacked designs on my better guitars. These stacked coils with opposite winding I had hoped would improve the situation a little, but made no real difference to sustainer performance or the issues involved.

Edited April 1, 2009 by psw

[col]

Well...more work could be done I suppose. I have a feeling that the "piggyback" thing has taken on a form of denigration...the piggy back thing is only one way in which the thin coil design could be applied, an afterthought really. The exact same difficulties occur with the same design neck to a pickup as with the tele pickup.

You seem to be getting on the defensive a bit there... no need to though.

I'm not using the term 'piggyback' in a negative way - If you can come up with an equally concise term that is as obvious in its meaning as piggyback, then I'd be happy to use that instead.

That last bit about 'the same design neck to a pickup' made no sense whatsoever, can you try to explain that again please.

As far as the 'thin coil' idea, IMO the only way in which it has any advantage over an less thin coil is if you're trying to stack it on top of a pickup, or in another extremely confined space. Other than that, it's just a coil - the turn count, core properties, resistance and permanent magnet are the significant variables - I have thought this for a long time and have more recently proved it to myself through experiment as well - thinness is irrelevant unless you need to get it into a thin space.

You may also recall, I think it may have been curtisa that encouraged it back then, the notion of running the pickup (whether under or next to the driver) in combination with the pickup coil in parallel (causing very little change to the ohmage of the driver). This was shown to be quite effective, with some fiddling about. It did seem to complicate switching a little more in some aspects.

Running the coil butted up next to the pickup would be pretty much the same as piggybacking it - agreed. However, not much has been done in that area, so no need to mention it.

I was referring to specific problems that you had been having (and still are AFAIK) with a piggybacked driver, and that those problems may be related to the idea i was explaining. Maybe if you read the post from that point of view, it could give you some idea of how to take things forward with your design and maybe even solve some of the problems ?

It should also be noted that, whether a "piggyback" installation or a separate driver in the neck position, the middle pickup also needs to be lifted and can't also be used in parallel...there is still interference with conventional simple driver systems for this kind of thing to be possible, jsut as the middle driver is not possible with this design.

So far, the only solution you've found is to disconnect both ends of the pickup. That doesn't mean that there aren't other solutions.

It is unfortunate that so few people have the same problem though.

But...the point is...the "piggyback" or a driver adjacent to the pickup makes no discernible difference to the issues involved.

No one is suggesting that there is a significant difference. (although ironically, this would be one of the few times where a 'thin' coil would cause a difference as if it were beside rather than on top of the pickup, the coil coupling would be reduced)

The problem with a lot of these things is that I seem to be a lone voice...

Well, I'm not sure. A couple of things - driver next to pickup, and the complex switching you have found to be the only solution so far to the issues it causes - are candidates. I'm not sure what else though? Not exactly lots eh?

I've also been using and experimenting with ideas that others are mostly steering clear of and/or ignoring (or waiting to see the outcome of), so I know that it's not so bad - it means that if you get it working, you have a better system than the others, and if you don't get it working, then you don't have to worry about leading other people into wasting time and money on a bogus idea.

What it does also meant though is that you need to develop a really good understanding of what you're working with.

Hank is doing exactly the right thing - collecting data and as much information as possible. I have done the same. I don't have the same kit as him, so my energies have been slightly more on the theoretical side, but its not all guesswork and hunches, a lot of it is studying the physics of it and using tools to simulate parts of the system in order to prove or disprove theories. Where I consider it to be most important I've put the money down - e.g. bought an inductance capable DMM

Maybe its time for you to start paying more attention to the textbooks (or websites). You may find possible answers hiding away in there, or at least find out why things behave the way they do. It may be that you find there is no easy fix, but in the process of that discovery, you find a better approach that doesn't have the same associated problems.

cheers

Col

[col]

@Hank

have you looked at any of these as options?

They're not cheap, but may be ideal - unity gain, compact, high quality and able to supply plenty of current.

LT1206, LT1010 & LT1886

(That last one is a dual op-amp that can provide up to 200mA !! - I wonder if it can help to simplify the circuit by letting us combine AGC and output ?)

cheers

Col

[Hank McSpank]

@Hank

have you looked at any of these as options?

They're not cheap, but may be ideal - unity gain, compact, high quality and able to supply plenty of current.

LT1206, LT1010 & LT1886

(That last one is a dual op-amp that can provide up to 200mA !! - I wonder if it can help to simplify the circuit by letting us combine AGC and output ?)

cheers

Col

No I've not looked at any of those (but will once the kids are put to bed - though a quick look at that LT1886 sees them quoting output loads of 25 ohms....we're back into very thin wire territory again!). BTW, your DVM with inductance puts you ahead of me ...sure, I can see distortion with a scope (but you can hear that anyway), but I reckon you've got the edge with that inductance meter. When I invester in my coltage/current/capacitance meter about a year ago (it's an all singing & dancing one...does lux, temp & SPL!)), inductance metering didn't seem that necessary(!). Also, it seems if you want to go the route of a meter that has inductance, then often it's to the exclusion of something else! For example a lot of LC meters don't even measure rsistance (&/or Voltage). nevertheless, I'll be piutting this to rights soon & buying myself a meter that doesn incuctance (they're quite cheap on Ebay nowadays)

wrt to component selection - I've come to this project 'fresh' as it were, & seek 'leads' from those of a technical ilk. It's becoming quite apparent though that one man's 'accessible budget Poweramp IC' is another man's 'time wasted' crock of s*** IC!

Obviously, the sustainer overall 'block' model already exists! (eg that Floyd Rose schematic posted last week)....my main problem with emulating what they've done is...

1. Where's the fun in that?!

2. Component count.

3, Physical size.

2 & 3 are related, so I guess what I now seek, is a creativeway of utlising a chip whose main purpose is *not* the niche area of Sustainers...& tweak the circuit feeding it to make it work (sort of climbing a mountain...just because it's there)

Re theoft quoted 'thin driver©' ...I concur with your statements about thin not being the significant discovery. Pete's found a particular combination that yields results, but his somewhat polarized stance does make it sound like it's the only combination that works - incidentally, I'm puzzled at the constant use of the term 'efficient driver' - it would take some degree of fairly involved testing/measuring to prove its efficiency. In electronics, 'efficient' doesn't mean a small, or tightly handwound while coating in PVA or thin etc - it's a bold claim to make without backing the statement up with figures.

Not debasing what's he's done though...if it works, it works...who cares (but the efficiency quips does bug the nerdy side of me!).

No, in my opinion there'll be heaps of combos in addition to the thin driver© ...& on paper, within reason - it shouldn't really matter *that* much what the wire gauge is ...just so long as you blend the circuit with whatever driver you come up with well.

(BTW: does the constant use of 'thin driver© ' suggest Pete will attempt to 'lay claim' to anyone else making a coil sufficiently narrow to fit in a tight space - *even* if it uses toally different wire gauge & circuit?!! I doubt you can lay claim to something already invented, based on thiness alone ?!! )

Edited April 1, 2009 by Hank McSpank

[psw]

Maybe so. What can I say?

All I have ever said that the "thin coil" idea is one that works without phase correction circuitry and that with this design, the wire gauge seems to be important if not vital (especially to high string response). This has been the result of comparison tests of various profiles and alternatives by myself and many others. The thin coil was chosen because it worked, not because it was compact and also worked, the piggy back was an extension of this finding, not the goal at all.

I have searched extensively to find reasons and found some indications...magnetic coupling seems to be key in this. This effect will occur whether it shares the same coil or stands next to the core of another coil and magnetic field. These things will not show on an oscilloscope (at least not in my hands), I have built things like a "magnetic field detector" using a hall effect device as the sensor for instance but that did not yield much information in this regard.

I have no doubt that other designs work or could be made to work. Clearly the commercial systems use a completely different coil geometry...but then they all feature phase correction circuitry. The thin coil designs came out of a desire to avoid that approach.

My hex coils were radically different of course, the thin coil did derive from this work as in general the more advanced hex things were in fact very compact (in all dimensions) and I suspected that this feature was a part of their effectiveness.

The things aimed for there was something compact enough to be practical as an addition to a normal guitar without the loss of a pickup to the driver or structural modifications. But, I also suspect that the thinner or compact designs also have far less EMI dispersal and react "faster" with less change in induction over the range of frequenices required for the application. It is not just that the coil is thin, but the core is also small of course.

...

As far as switching goes...the telecaster is a stand alone driver as were all the test models over the years. The tele driver is next to a pickup, not on top of it. I have also tried it as a stand alone driver with a "deselected" middle pickup.

All the patents show the need for extensive bypass switching, I have said how initially I did not recognize this to be a problem, or at least something that should be avoided...however, no matter what I tried I have encountered similar problems. It have often lamented that others have not tackled the "issues" to approach them in new ways or with a fresh mind...it is there that I do seem to be a "lone voice". Only because few seem to be concerned with or don't have the issues because their projects only have one pickup in them. The result is that those who have not tried it, make claims upon conjecture and not a reproduction of the problems or direct experimentation.

...

(btw: does the constant use of 'thin driver© ' mean Pete will 'lay claim' to anyone else making a coil small enough to fit in a tight space - even if it uses toally different wire gauge & circuit?!! Can you lay claim to something based on it's size alone wink.gif )

No...the "thin driver design" that I have presented is a specific recipe of coil size to wire gauge and application...not just it's small size. A coil of the exact same size with 1.5mm wire is not my design and been shown time and time again not to be effective in driving the high strings...2,5mm same thing. Not saying that the wire gauge is "magic" but that this has been found to be the case by myself and others. It amy well be that a different wire gauge is more appropriate in another design, say like a dual coil system or a hex or a thick coil...or some other permutation.

As far as the 'thin coil' idea, IMO the only way in which it has any advantage over an less thin coil is if you're trying to stack it on top of a pickup, or in another extremely confined space. Other than that, it's just a coil - the turn count, core properties, resistance and permanent magnet are the significant variables - I have thought this for a long time and have more recently proved it to myself through experiment as well - thinness is irrelevant unless you need to get it into a thin space.

OK...well, I'd like to see the "data". I and others for instance have wound a single coil without blocking it up to the 3mm or similar with the same wire, and then the exact same thing with a thinner coil with a remarkable difference. You yourself have indicated in the past "ideal" coil dimensions as I recall of depth, width and such in which the thin coil falls pretty close. I this is so, that's good, but it is not what my experimentation indicates...above a depth of 5mm there are problems.

I am not dedicated to the thin coil solely because I thought of or found it. Initially I had envisaged things like a driver coil inside an outer pickup coil at typical depth of 10mm and taking up insignificant width. Or even better, a driver coil beneath a pickup coil, sharing it's core but hidden below. Or perhaps a coil so "narrow" that it could be incorporated into some kind of pickup ring. Lots of alternative ideas that don't rely on thinness!

...

I am defensive because I think it may be detrimental for the average person to believe that any coil will work. This is just not the case. A conventional pickup coil won't work for instance as is time and time put forward or even claimed to have yielded perfect results. Any old wire gauge seems to have been ineffective with designs like mine. Such thoughts are for the "uninitiated" that take the principle alone and not tackle the details of issues like high string response or clean operation that are necessary to create an effective sustainer system.

But then, perhaps it is detrimental to the detirmined person if it is construed by my promotion of it that it is the only way...others may find a better way or a different way...I have always said that. I do believe though that there are "issues" that exist no matter how it is attempted. But if these things are found not to exist for others at the end of their road, then they are non-issues.

Too early yet I think to speak to that either way...I remain a little skeptical of course where they contradict my findings. Maybe because I have seen so many people make claims that in the fullness of time proved to be unsubstantiated or misleading. I have tried hard not to do that.

As far as the shittyness or otherwise of the LM386, it is not my concern what people use. I have used many amplifiers with my designs, I have always said, that a suitable clean low powered amp will run it...I have always said that the LM386 is not ideal but it will do. Use what works!

...

re the thin driver© ...I concur with your statements about thin. Pete's found a particular combination that yields results, but his somewhat polarized stance does make it sound like it's the only combination that works - incidentally, I'm puzzled at the constant use of his term 'efficient driver', when it would take some degree of fairly involved testing/measuring to prove its efficiency. In electronics, 'efficient' doesn't mean a small, or handwound tight, or thin or coated in epoxy etc - it's a bold claim to make without backing the statement up with figures.

Well...I have pages of data in this thread...my data is direct comparison of different coil types and the ability to sustain strings all over the neck and on all strings. An inefficient driver could therefore be defined as one that does not do that. I have had others replicate these findings again and again...what more can I say.

I have also have had discussions and thoughts on why this may be "efficient" or "effective". One idea was that the thin coil design has qualities of inductance that don't change dramatically over the range of frequencies put through it...this provides consistency of response especially with the higher frequencies. It may have particular resonance qualities. It may be a combination of things. I will never be wise enough to be able to analyze it, but it would be cool to know why that seems to be the case.

All I hear are conjecture about why it shouldn't matter or that there are "non-issues" with the bypassing..without anything to back up such assertions. Such ideas are where you start from, but pretty soon you find that it does (when your high strings wont respond for instance, or you reverse a coil, etc)...or you collect a lot of misleading data that is affected by these issues not yet taken into account.

I have shown my methods. Take a single pickup guitar, work a design so that it is effective...then add back in the pickups...issues with fizz and switching occur...work alternatives to find a solution (magnetic shielding, blocking coils, total bypassing)...present those results for discussion.

What other method could I use? Is this not enough to provide evidence of some kind? Is this not some kind of "data". It is for others to do that work if they require it. So far, in all this time, all I seem to have been able to get from others who have replicated these things is that they experience the same things and end up with the same kinds of solutions. This I regard as "independent data". But my ability to put numbers with meaning to these things is very limited and the motivation at this point very low.

Things like zfffitz6 switch thing didn't work...because I did try it...as have others effectively....now if someone else shows that it can be done great...but if my saying that it didn't work for me for these reasons (based on nothing, and flying in the face of others who effectively tried it also) then so be it. But by saying such a thing, I am being pilloried as simply being negative or having a personal vendetta against someone I don't even know. I feel that my comments are taken that way about any findings that I put forward in an effort to help even now.

...

So...perhaps I am better to "stay out of these things"...but it is detrimental to many who come along to see a lot of amateur science working towards extremely complex "solutions" to something for most people there is at least one way that has been shown to work (and many ways in which it has shown not to work)...to that end, i am speaking in defense of that method and to help those people who may wish to do the same.

pete

[col]

The things aimed for there was something compact enough to be practical as an addition to a normal guitar without the loss of a pickup to the driver or structural modifications. But, I also suspect that the thinner or compact designs also have far less EMI dispersal and react "faster" with less change in induction over the range of frequenices required for the application. It is not just that the coil is thin, but the core is also small of course.

Can you provide any evidence that involves measurements or even references in 'the literature' that can substantiate any of this stuff about 'thin' designs being "faster"(whatever that means). And the size of the core can be useful at all without also knowing the core materials other properties such as permiability, remnance etc?

(I know its not possible to obtain values for the second hand core materials we use, but it IS possible to test a variety of cores in the same coil, e.g. measuring their inductance. This will give useful empirical data rather than less useful subjective information - like you get from listening tests)

As far as the 'thin coil' idea, IMO the only way in which it has any advantage over an less thin coil is if you're trying to stack it on top of a pickup, or in another extremely confined space. Other than that, it's just a coil - the turn count, core properties, resistance and permanent magnet are the significant variables - I have thought this for a long time and have more recently proved it to myself through experiment as well - thinness is irrelevant unless you need to get it into a thin space.

OK...well, I'd like to see the "data". I and others for instance have wound a single coil without blocking it up to the 3mm or similar with the same wire, and then the exact same thing with a thinner coil with a remarkable difference. You yourself have indicated in the past "ideal" coil dimensions as I recall of depth, width and such in which the thin coil falls pretty close. I this is so, that's good, but it is not what my experimentation indicates...above a depth of 5mm there are problems.

I wouldn't class a depth of 5mm as 'thin' for a coil of only 100 - 200 turns. Neither would you have a year or two ago.

I am defensive because I think it may be detrimental for the average person to believe that any coil will work. This is just not the case. A conventional pickup coil won't work for instance as is time and time put forward or even claimed to have yielded perfect results. Any old wire gauge seems to have been ineffective with designs like mine. Such thoughts are for the "uninitiated" that take the principle alone and not tackle the details of issues like high string response or clean operation that are necessary to create an effective sustainer system.

Aww, the straw man raises his ugly head

Saying that thinness doesn't matter is NOT the same as saying or implying that any coil will work. Neither is it saying that any old wire will work.

What we need to do is explain what does really matter based as much as possible on empirical evidence.

We are at the stage where using the term 'thin' in a way that implies that thinness is a crucial factor for a system to work is getting in the way IMO.

Nothing wrong with a driver that is thin, but its the other properties that make it work or not.

I can make you a thin driver that doesn't work and a not thin one that does work (I'll only do it if you pay me but I CAN do it)

As far as the shittyness or otherwise of the LM386, it is not my concern what people use. I have used many amplifiers with my designs, I have always said, that a suitable clean low powered amp will run it...I have always said that the LM386 is not ideal but it will do. Use what works!

Agreed, the LM386 may be 'shitty', but is has been proven to work.

It would be interesting however if we could look at the performance of our different LM386s I'd bet that some are better than others.

Well...I have pages of data in this thread...my data is direct comparison of different coil types and the ability to sustain strings all over the neck and on all strings. An inefficient driver could therefore be defined as one that does not do that. I have had others replicate these findings again and again...what more can I say.

That kind of information is not really very useful in engineering (which is what we're doing).

Its great to build lots of versions and try them out, and it can - as you have proven so well - get you to a system that works well.

The kind of data that Hank is talking about is precise measurement.

Hanks sort of data lets you take two systems that both work well, then find out whats good and whats bad about both, you can then keep the good and ditch the bad resulting in an even better design.

In that way, I took your coil specs, studied some theory, worked out why they work and others don't seem to, then after a few false starts due to me not being a genius at either maths or physics, I came up with some compelling reasons why it [your driver] works.

Since then I have taken that understanding and used it combined with empirical measurements and simulation (based on accurate numerical modeling) to design a driver that so far is performing better, even though it is not thin, has heavier gauge wire, and was much easier to build due to it's conformance with existing pickup bobbins and magnets.

I have also have had discussions and thoughts on why this may be "efficient" or "effective". One idea was that the thin coil design has qualities of inductance that don't change dramatically over the range of frequencies put through it...this provides consistency of response especially with the higher frequencies. It may have particular resonance qualities. It may be a combination of things. I will never be wise enough to be able to analyze it, but it would be cool to know why that seems to be the case.

You don't need to be wise or clever to understand it - at least as well as I do. As long as you are willing to accept the word of Many people who have really studied the field, some of whom really were true geniuses.

The inductance does not change with frequency.

The inductive reactance does - that is the part of the impedance that is caused by the combination of inductance and frequency.

The impedance is the combination of the DC resistance (your 8ohm value) and whatever extra ohms of resistance that are being caused by the inductor at whatever frequency the signal is at...

You don't need to know the maths to use this knowledge. You do need to know what the inductance of your coil is, and you do need to have a URL for a calculator that does all the hard stuff for you

Why not spend a few minutes using that calculator, I guess your driver will be between 1mH and 1.4mH, try those with a resistance of 8ohm and various frequencies to get a feel for it, then try taking the DC resistance down to 4ohm, notice how the final all important 'impedance' is over a wider range now for our purposes (82Hz to about 1200Hz is what we're interested in IMO).

Now try with 8ohm and say 3mH... wow, look how that effects the higher frequencies in the range we use...

That's it - it's as simple as that.. the impedance is what the LM386 has to drive, a higher impedance means less current which means weaker drive.

So for a voltage amplifier with an 8 ohm driver, as you can verify with that calculator, your coils specs (other than thinness) are pretty close to optimal (which is a damn good result for an informed trial and error approach).

With This understanding, and the Zeigler pickup calculator you can then try out imaginary coil specs.

You use the calculator to get the turns vs DC resistance, then use some simple arithmetic to work out your inductance for you imaginary design.

first the square of the turns count for the unknown coil divided by the square of the turn count for the known coil

then multiply that by the inductance of the known coil

e.g. if 150 turns around a particular core gives 1.2 mH,

300 turns will give ((300*300) / (150*150)) * 1.2 = 4.8mH

This process is not super accurate, because coil linkeage will be variable, and our hand winding approach means every coil will be a little(on the best of days) different but you will get 'ballpark' figures that you can easily hone in a final development stage.

The only kit you need for this is an inductance meter which can be had for as little as £10.

The meter is great because it also lets you see just how much of an effect different core materials have (and it can be a big effect).

So you can tweak the inductance of your driver by reducing or increasing the mass of the core after you've made the coil in order to get as close as you need to your goal inductance....

Remember though that if you use a big chunky lump for a core you really must use laminations.

All I hear are conjecture about why it shouldn't matter or that there are "non-issues" with the bypassing..without anything to back up such assertions. Such ideas are where you start from, but pretty soon you find that it does (when your high strings wont respond for instance, or you reverse a coil, etc)...or you collect a lot of misleading data that is affected by these issues not yet taken into account.

If the data is gathered accurately using measurement equipment from a system made from components with known specs, then it is not misleading. If your initial hopes based on that data turn out not to work, you can then use that data to understand why and to inform the development of new tests and systems.

Misleading data is the stuff that you get from A/B testing two systems using your ears and hands.. late at night after hours of work and when one of those systems is your cherished favourite, and the other is an 'impostor'.

Or when one system is a great new idea that you REALLY want to be an improvement. It's amazing how we can fool ourselves into really believing one is better just because we want it to be.

I wish I had more than just a DMM with Inductance meter. The lack of a scope makes it much more difficult to proceed at any kind of pace because I'm reticent to waste energy building stuff based on hunches and 'possibly' ideas.

So...perhaps I am better to "stay out of these things"...but it is detrimental to many who come along to see a lot of amateur science working towards extremely complex "solutions" to something for most people there is at least one way that has been shown to work (and many ways in which it has shown not to work)...to that end, i am speaking in defense of that method and to help those people who may wish to do the same.

Hmm, amateur science is orders of magnitude better than mumbo jumbo every time !!

My suggestions turned you from using a heavily clipped signal to using a clean one. I also have presented reasons why your design works as well as it does (based on amateur science).

I have built your basic system and found it to be interesting but the perfomance was unacceptable IMO, amateur science lead me to a better "solution"

The people who have been unhappy with the performance of their systems and have taken up my suggestions of using AGC (you included) have been much happier with the results. These developments have come from amateur science.

Col

[psw]

Well...what can i say...AGC was mentioned on page 2...a sophisticated limiter/compressor was used before page 30...well before you came along col.

I have not said that the thin coil is the only way, the best way or the preferred way. What I have said is that it is "a way" nothing more really. It meets a lot of the criteria that was set for a DIY project, and does what it does within the limitations of what it was designed to do.

Yes...thinness is only one aspect of the design. You should know that I have tried and discussed with you all manner of different core materials, laminations and ferrites, iron/epoxy composite powdered cores...all manner of things. In the context of the variability of the DIY design, they made little difference so I don't advocate them personally.

I understand about your need for empirical abstract evidence...I can't provide it for you unfortunately. All I can say is that some things worked, others didn't. As far as many of hanks experiments they are almost identical in type and response to those detailed on page two...it was something of a shock later to find further issues down the road.

Note. I tto used single coil drivers of various types, and signal generators...all manner of things. Heres a pic seen before of a single hex style driver operating much as hank recently described...

notice the compressor limiter with the green knobs. This was from page two of my photobucket account...so very old now. Sorry the pic is so bad, but in those days i only had a film camera and a scanner to get such pics of what I was doing. Notice that I two have the driver mounted on the b string between the middle and bridge pickups without bypassing at this stage as well.

Here are some thin, and not so thin drivers...

the thinner one went on to be replicated for the first "piggyback thing" the thicker one also worked...but not as well. What more can I say about that that wasn't said a couple of hundred pages ago.

Yes...there may be better drivers and driver designs, all I have ever sought was to encourage that exploration. Truth David wrongfully (again) attributed terms like "done and dusted" to me, they were his words, not mine. There is no end to the possible exploration of this device...hence there are 300+ pages here for a start.

There are other factors besides the "thinness", I don't even recall if that was my term or just adopted or what...it's a name...but a name for the whole deceptively simple package. Youare right, things like the core matter, but some of that also relates to or is a factor of the "thin design"...very small core dimensions.

Can you provide any evidence that involves measurements or even references in 'the literature' that can substantiate any of this stuff about 'thin' designs being "faster"(whatever that means).

Well...there is and I have tried to explain it as best I can...it is some years since I was reading this kind of thing in any depth. By "faster" I mean the speed at which an electromagnet can change states. A lot of this has to do with core material. Some of it a natural outcome of the technology. A simple, but most likely make it more difficult for me, explanation of part of this is that there is a delay or "lag" in the response of alternating currents through the coil...there is some momentum and core magnetism that needs to be overcome to change states. This "state changing speed" is what I am referring to when I speak of a driver design being "faster". It is a theory or hypothesis based on what I have read in that regard, not off the top of my head! But I have tried and failed to explain this before. Some of it relates to the capacitance of coils as well if there is a need for further information. "Back EMF effects" and "backlash effects" (neither my terms) are also worth investigating in terms of running AC currents through electromagnet devices.

And before anyone takes undue offense...

Hmm, amateur science is orders of magnitude better than mumbo jumbo every time !!

I was referring primarily to myself in that comment. I have tried very hard to explain the observations of extensive experimentation...I have observed the failing of some of my experiments in trying to work these things in isolation while ignoring other factors. By doing so, misleading "hard data" can be produced that is effectively mumbo jumbo.

Doing the hard years of comparing real world drivers with identical circuits and varying depths and materials is science...I have reported much of these observations years ago now that outline why I took the directions I took. They have been open for discussion and been replicated by others with other variations with similar outcomes.

It is not in my personal interest, nor an obligation to do more or to prove a point that I am not even making. The "thin coil theory" was always presented as that. It was a theory and stated as such from the start as a result of very many observations and comparisons. What people make of that or why the thing works is their business. As far as this thread is concerned and my work in it, the "thin coil design" was done in an attempt to create a design that met a host of stated criteria one of which was the ability to be replicated...and that it worked!

The inductive reactance does - that is the part of the impedance that is caused by the combination of inductance and frequency.

Yes..well that perhaps is what I meant...this "theory" of why the thin design worked as it did was put forward by a few others, R.G. Keen perhaps.

Misleading data is the stuff that you get from A/B testing two systems using your ears and hands.. late at night after hours of work and when one of those systems is your cherished favourite, and the other is an 'impostor'.

No...at the time the thin coil didn't exist...in fact I was completely enamored by hex systems and built the simpler version as a stop gap to address personal attacks and criticisms because what I was working on was complicated and beyond the scope of DIY.

Or when one system is a great new idea that you REALLY want to be an improvement. It's amazing how we can fool ourselves into really believing one is better just because we want it to be.

Absolutely...I took the thin coil thing a bit further as I could see benefits to the idea apart from performance. Wafer thin coils for instance last year. I make no excuse for that...others can explore dual coil designs or bigger neck pickup replacements, such devices tended to contravene some of my working criteria or intentions for the overall concept.

My suggestions turned you from using a heavily clipped signal to using a clean one. I also have presented reasons why your design works as well as it does (based on amateur science).

This is wrong. I forget the name, but it was me who was trying to pursade another member who added LED clippers into the circuit near you entering the thread as I recall. I do know thast these discussions were had very early in the thread with LK who died by the time you entered the discussion and have already outlined my use of signal generator signals and such to try and ascertain the veracity of such ideas that came from outside of my own opinion back then.

Same with the AGC as I have discussed. The idea of a forward feed did take a while for me to get my head around, but that kind of thing was beyond my capability to perform effectively...but as you can see AGC was tried well before and discussed from page 2 specifically. If for no other reason but it is mentioned in every patent!

Similarly phase issues were of paramount concern...I didn't "ignore them", it attempted, with LK's encouragement, to design around them. Something that will work well enough for the application. If you look at the early pages I was going on about the need to compensate for these adinfinitum for a while there.

There was a good three plus years and numerous successes well before you came along col. What you contributed and have always acknowledged was work with dual coil drivers (along with avalon and curtisa's successes) and driving that era...and for upping the anti on the circuitry. Important and worthwhile contributions and acknowledged time and again.

Why I am precious about a lot of these things is that along the way many have attempted to co-opt things that I have spent literally hundreds of hours on, a lot of money and dedication and generous support and disclosure of. There was no precedent at the time of my starting this thread, we have not seen thin coils and the applications prior to this work. There are assumptions or distortions about what I have done that no amount of me defending them seems to stop despite pages and pages of real time reporting.

If my work is superseded or a revolutionary way of achieving the same or better results, that's great, and all credit to the person who does this. I have not particularly heard anything to date that convinces me particularly...but maybe there are different aims being sought.

Col's system to date is a more even response, but a little tame to my ears. Along with that is that it never addressed things like multi pickup guitars, simple compact circuitry, ease of construction and installation and such. But then, nor did it claim to, so it is not a criticism but an observation. My aims were to create a device that could be installed with low mods and not sacrificing the features of a standard guitar...like the loss of a neck pickup...perhaps different aims. Along the way, there have been compromises. The hex things were an attempt at far less compromises, I was aiming for it all...to that extent I failed or reached the limits of my abilities, or decided after a while to pursue the thin drivers features still further (with wafer coils)

To your credit col, and I have always acknowledged this, I was always under the impression that you did try my designs and took things further. Many people start out that way but change fundamental things...like fuzz box preamps...or remote floor mounted 7 watt amps...way outside my specifications. I get mail regularly about it not working in the mid position...even though I published that this would not work with such a simple design.

...

But hey...here I am defending myself and I don't know if it is clarifying things at all or what I am trying to prove by doing so. It seems as if nothing I say will be helpful to these enquiries, in fact, I am not even sure I know what is being done at the present time.

But...if people want to assume I am the worlds biggest fan regarding the LM386 despite all that I have said now and in the past with alternatives, so be it. I didn't come up with or endorse the the F/R solution either. I criticize it and I am accused of denigrating the work of ROG! I also suggest that in this application things like the zobel network and such are important things, but hank did not appear to utilize these aspects from the data sheet...difficult then to judge it fairly. But, for his eventual purposes, probably not the ideal component anyway.

Similar with the thin coil design, it is something that is achievable that gets reasonable results (all strings driving and harmonics all over the fretboard while fulfilling other criteria and some interesting applications like the "piggyback" installation (the above photo clearly shows the actual prototype quite separate form this eventual application))...that is all. It is adaptable to variations, a 5mm coil will work, but not as well in my experience, the 0.2mm wire seems to be important, identical coils of different wires are not as good or fail to work.

That is all I claim for it, if i could come up with better, I would have...if others had, they would surely have posted them. Some of the dual coil devices are interesting...but it is hard to compare as it was teamed with quite different circuitry. How does the SC style compare to the dual coil with the AGC circuit, I don't know. Is the dual coil better without the AGC circuit...I don't know. I have explained how I go about it...identical circuit, guitar, pickups and changing drivers or circuits and such. Many drivers were built identically with differing cores, magnetic shielding...all manner of things.

All I know is what I have tried, I have tried my own dual coil and bi-lateral designs, but that doesn't mean they are as good as yours. They worked, but the comparisons were inconclusive...in some cases negative with the same application as the SC designs, leaving aside the amount of work required to make them. They are my findings and my assessment of the practical evidence that I have been privy to to assess...that is all I can go on.

My observations and experiments in AGC and clean drive ideas are presented chronologically...take from them what you will, or discover them for yourself...but please don't attribute "innovation" in ideas that were explored and discussed from the beginning and well before that in the patents!

pete

[col]

My observations and experiments in AGC and clean drive ideas are presented chronologically...take from them what you will, or discover them for yourself...but please don't attribute "innovation" in ideas that were explored and discussed from the beginning and well before that in the patents!

I've never claimed these Ideas were my innovations, however, I do still stand by the fact that when I started here, you were still using the LM386 set up with very high gain. There's with the setup you had that you were using a drive signal. At the same time others were having lots of trouble with squeal, fizz and noise.

My suggestion of using the minimum gain settings on the IC helped a few folks at that time. It was also this assertion that preventing clipping was important that drove the AGC development forward.

I'm well aware that you and others discussed AGC and attempted to use various existing compressor circuits. However again, when I joined (about 2 years into the project), this area had not been developed, I believe because it's importance was not realized, other than by LK who IIRC was only advising, not actively developing in this project? I was in discussion with LK about AGC when he tragically died. He was going to send me some part to try.

In the same way, your only innovation as far as I can see has been the piggyback design - the rest all existed prior to your work, so from that point of view, we're pretty much in the same boat (and you can be certain I won't be trying to take credit for stacking a driver on top of a pickup).

We and others have all brought ideas to the table, most of those ideas have not been original. However, their application to the project, and the development work involved in going from a concept to having a functional device that improves on previous devices as you know is not trivial. From that point of view, I still feel justified in taking some credit within this project for pushing both 'clean/no clipping signal' and 'AGC'.

I just wish Some of the other folks who came with different ideas had persevered a bit more and taken their ideas to their conclusions.

cheers

Col

[Hank McSpank]

Ok, peeps....this thread is now getting a little 'bloated' (& in recent weeks, I'm not helping!)

I can see this thread is no place for my 'blog like' progress report. I can also see that whatever I bring to the table will be simply misconstrued, or used as patronising fuel....& frankly, I don't do "patronisee" - nor do I have time for the threadwarfare that ensues.

Also, there aren't enough techie types posting here to stimulate meaningful, focused discussion. When I see 'wishy-washy' used as perpetual counter argument, it's time to stack the cards on that particular avenue of exploration!

Therefore, I'll be going into relative radio silence ....don't take this silence as anything other than a guy who's a disappointed at the direction the thread is taking. In my opinion, the whole thread could probably be condensed into about 20-30 pages.It's puzzling why there isn't a Sticky & a FAQ...along the lines of "So you want a budget Sustainer?" with a parts list, schematic, PCB (or breadboard) layout & accompanyining A to Z 'instructable' type note (which would meet most 'just passing through' peoples' needs) I can honestly say, as someone coming to the thread 'fresh' (relatively recently) ....the chaos of disjointed information is a little overwhelming!

I'll pop in now & then with the odd piccy & update ...I have a lot on the go (& can only dedicate a couple of hours, 2-3 nights per week) , but I'm setting myself a fairly ambitious target of three months starting now to have a good, predictable sustainer solution, which meets my own needs (watch this space), but for now...I'll walk the lonely sustainer path into my loft alone!

Edited April 2, 2009 by Hank McSpank

[Hank McSpank]

double post (no delete option?) - contents removed.

Edited April 2, 2009 by Hank McSpank

[col]

Sometimes its good to clear the air, but arguing isn't pleasant - sorry folks

So here's some more positive news

I've been working for ages on trying to get a circuit with low parts count that doesn't compromise too much on performance.

Well, today after my last agro post, I spent some time again working on this.

I have got a circuit that _seems_ to be just about what I was hoping to achieve.

WARNING: I've net tested it IRL yet, so there maybe some gotcha or other (although so far everything that has simulated has worked exactly as expected when soldered up)

It's a basic circuit with input buffer, virtual ground buffer, 'brickwall' limiter and LM386 power stage.

Parts count is about as low as I think its possible to go without compromise and/or specialist hardware.

phase response is similar to other circuits I've used.

30 discrete components, 3 op-amp sections (leaving one free for adding a harmonic mode switch at some point), and the LM386.

This has the option of an external sensitivity control and a drive control.

The AGC reaction time is fast enough (I hope) at around 60ms, and the recovery is similar. The AGC clips during that short time which should protect the power stage from melting. The clipping will only last for that 15th of a second, so hopefully it will not be noticable.

It is pretty good at squashing everything in the range we will need to exactly the same level.

Minimal distortion - this could be improved slightly at the expense of reaction speed, so I'll need to wait until the real world tests before getting too excited.

So, fingers crossed. If this one works well, it will be relatively compact, and easy enough to build.

cheers

Col

[col]

Ok, peeps....this thread is now getting a little 'bloated' (& in recent weeks, I'm not helping!)

I can see this thread is no place for my 'blog like' progress report. I can also see that whatever I bring to the table will be simply misconstrued, or used as patronising fuel....& frankly, I don't do "patronisee" - nor do I have time for the threadwarfare that ensues.

Also, there aren't enough techie types posting here to stimulate meaningful, focused discussion. When I see 'wishy-washy' used as perpetual counter argument, it's time to stack the cards on that particular avenue of exploration!

Therefore, I'll be going into relative radio silence ....don't take this silence as anything other than a guy who's a disappointed at the direction the thread is taking. In my opinion, the whole thread could probably be condensed into about 20-30 pages.It's puzzling why there isn't a Sticky & a FAQ...along the lines of "So you want a budget Sustainer?" with a parts list, schematic, PCB (or breadboard) layout & accompanyining A to Z 'instructable' type note (which would meet most 'just passing through' peoples' needs) I can honestly say, as someone coming to the thread 'fresh' (relatively recently) ....the chaos of disjointed information is a little overwhelming!

I'll pop in now & then with the odd piccy & update ...I have a lot on the go (& can only dedicate a couple of hours, 2-3 nights per week) , but I'm setting myself a fairly ambitious target of three months starting now to have a good, predictable sustainer solution, which meets my own needs (watch this space), but for now...I'll walk the lonely sustainer path into my loft alone!

That's a shame, I was looking forward to having someone with a more scientific approach to share ideas and results with.

well, good luck anyway

Col