Sustainer Ideas

[psw]

First of all, thanks to everyone who contributes, especially Pete. After 108 pages many people have been helped because of you.

BTW, it's 111 pages now!

Thank You...and all the 59,930 visitors and all the contributors over the years. In the last year I have not been very active in building these things, though always an interest, yet there has been a consistant interest and progress...I'm very happy and proud...as should all, it is a remarkable thing and fiarly unique...sustain on!

I would suggest that folks don't try to build my circuit yet, unless they have a bread board or simulation software...

There are just so many things that need to be stabilised and finalised

ITS NOT READY YET

My reason for posting it at this stage it so any folks out there with the know-how and desire to help finish it can do so.

Quite right, but there are people who do just love to pick over schematics like this, so I'm sure well get some feedback... (pun intended!)

Anyway...2.5 watts of miniture power. That is a new one from guitar fetish, I have previously looked at their preamps, but this one is a neat idea...

Our circuitry could easily be shrunk to this size now (or smaller with SMD) and is what I'd ultimate like to see, or even produce...and the price is cool.

We will have to get one and see what kind of mods are required. IF the EMIbucker works ok, you maybe able to run the whole 2.5 watts into it (the Ruby is less than one) for fret bouncing action...or some kind of limiting resistor. You may still require a preamp to prevent loading, depending on the design. It is likely that this is based on class D amplification, and it is interesting to note the apparent use of a standard DIL chip on there...I want one!

Great stuff as always...now where are those electronics guru's when you need them....I might have to invite some over again pete

Edited September 20, 2006 by psw

[custom22]

Since it is 1.5 times output as a ruby, would the coil be more prone to frying, or the strings bouncing on the fretboard, or uncontrolled feedback? Could a resistor somewhere solve this? If this here amplifier has a good chance of working, i wouldnt mind trying it and reporting results to everyone else. Being a busy person, it would be well worth it to me if all that is needed is a resistor.

[psw]

Since it is 1.5 times output as a ruby, would the coil be more prone to frying, or the strings bouncing on the fretboard, or uncontrolled feedback?

You wont fry the driver...the wire is plenty thick enough. You could bounce the strings (is that bad?) and uncontrolled feedback, but a resistor could limit the volume. What would really need to be looked at is if it is preamped enough to split the signal. You also have the switching bypass issues to contend with. And lets not forget the driver construction itself...

This is ultimately the kind of implementation I'd like to see the eventual circuit, but col is on to something a little more refined perhaps (are we moving more towards the commercial units approach?) and some even more promising events maybe just over the horizon (the mid driver really attracts me on a number of levels...especially on a Strat).

Thanks for allerting us to it though... pete

Just to bring it back forward from the previous page so no gurus miss it, here's col's schematic again...

Invitation to guru's posted over here...hope you don't mind col...

Aron's Stombox Forum, Col's 13700 circuit thread

Edited September 20, 2006 by psw

[custom22]

I dont things you would want the strings bouncing on the fretboard would you(I'm not challenging you, this is an honest question)?

I'm sorry if i sound completely ignorant, but i am trying my best to learn electronics along with many other things.

What do you mean by "splitting the signal"? Are you talking about splitting the signal to the guitar amplifier and the driver amplifier?

[psw]

I dont things you would want the strings bouncing on the fretboard would you(I'm not challenging you, this is an honest question)?

I'm sorry if i sound completely ignorant, but i am trying my best to learn electronics along with many other things.

What do you mean by "splitting the signal"? Are you talking about splitting the signal to the guitar amplifier and the driver amplifier?

No...you are not ignorant...I am still having trouble getting around these things, and I still don't quite understand col's circuit above is trying to do, let alone how it is doing it... (I get the gist col, but it is hard, you know!)

By "splitting the signal" I mean exactly as you described. Without some kind of active split or an amp that is designed to take the combined signals, the pickups can be loaded down with a loss of power and treble. It is trying to drive too amps at once and so both the tone and the drive potential is comprimised.

As for bouncing the strings off the fretboard...hahaha...yes, it is amazing to see a string trying to vibrate to the limits of it's ability with one of these things...eventually it is going to hit something, if not the driver, the frets! It actually pings a bunch of harmonics on them, calms down a little, then starts up...even on high strings the vibration is visible to the eye...rather dramatic. I first experienced the effect with a single coil driver I made very early on...my daughter's eyes almost popped out of her head!!! Anyway...not really the effect that you want I guess, and a driver working all six strings is less likely to have quite that effect. Col's circuit promises to address this by lowering the drive before it gets to this stage giving better control, and along the way better power consumption. A super low action is probably not the best as the strings will bounce around a bit, but you can get pretty low. Heavier strings (10's) are also recomended, if not required, to give the driver more to work with. A heavier string will require a slightly higher action anyway, to allow space for the string to vibrate in.

Hope that clears it up... pete

[onelastgoodbye]

I dont things you would want the strings bouncing on the fretboard would you(I'm not challenging you, this is an honest question)?

Heh. It makes for a cool effect though, my 10 watt amp was rattling the strings like mad today. But seriously, you wouldn't want the strings to bounce the fretboard no. That's why you don't want pump too many watts into the driver. The ruby is 1/2 -1 watt max and that's plenty enough.

What do you mean by "splitting the signal"? Are you talking about splitting the signal to the guitar amplifier and the driver amplifier?

Exactly. It's not just a matter of using a y-cord. Well, you could, but then there's issues of loading, weaker signal, the driver signal leaking into the amplifier signal,...to solve these issues, the split signal needs to be pre-amped and buffered (or something like that ).

Still...a bit more to do with the proof of concept...EMI may be low, but so may be drive force, necessitating heavy amplification...10 watts!! huh.gif

Still the coils are way mismatched (interesting....as I thought mismatched coils could be purposely used for the woofer/tweeter concept) and it does work.

yeah i'm a bit worried about the efficiency too. Like I said though, i have a crappy testing setup and a few loose connections so the performance was ...intermittant at best. Whenever it did work, It was pretty impressive though, the EMI rejection really cleaned up the signal. Ferocious little bugger too (okay that was probably the amp). I'm curious to see what results Col comes up with. Should give us a better idea of core thickness and spacing too. Mine are 2mm wide with 4mm between them (did i say it's tiny yet? )

Oh PSW, you seen this yet? http://www.vellemanusa.com/us/enu/product/view/?id=521723#

Velleman is actually a belgian company. A former teacher of mine worked there.

I'm intrigued by the low part count ...you should check ot the datasheet...it uses a TDA726A opamp, may be an alternative for the lm368?

[custom22]

Well, i guess I'll build the Ruby to be safe. I play gauge 11 strings and never have them extremely low, so that shouldnt be a problem. Thanks for the help!

Edit- For the Fetzer/Ruby, does the bridge output goes to the fetzer/ruby instead of directly to ground? Also, where do you put the on/off switch? Does it bypass the whole assembly, or cut off the battery, or something else?

Edited September 21, 2006 by custom22

[axe_2_grind]

ok, so I tried placing my driver over the pickup while plugged into my amp, and I did get a sqealing type sound. So it's doing something, but It's still not producing enough output (even with the volume & gain @ max) to vibrate the strings.

Just for fun I threw on the lead patch (heavy distortion w/ some delay) and had a little fun moving the driver back & forth over the pickup.

Anyway, I've even tried switching the leads, holding it upside-down to the strings, and nothing. I may have to check the potting, just to see if the windings are still loose.

Might have to use some epoxy after all. luckily I picked up some 30 minute stuff and some rubber gloves the other day. (let the mad science continue...ha ha ha!!!)

EDIT: >sigh< so I think my recycled single coil driver is a bust. My Ruby circuit seems to work just fine, I think there is a fundamental fault in my driver design, I'm just not sure what. I'll have to try it again later. Oh well.

I've already got some steel that I can use for a rail design, it just needs to be cut to size. Cutting the plastic should be no big deal. I may even go bobbinless. I am also thinking of making a tall/skinny driver that can possibly fit up against the neck between the heel & the pickup. But first I just need a working driver.

Anyway, good luck to you all, and thanks Col for posting your schematic (such as it is). I'll have to breadboard it at some point and try it out.

Edited September 21, 2006 by axe_2_grind

[psw]

EDIT: >sigh< so I think my recycled single coil driver is a bust. My Ruby circuit seems to work just fine, I think there is a fundamental fault in my driver design, I'm just not sure what. I'll have to try it again later. Oh well.

I've already got some steel that I can use for a rail design, it just needs to be cut to size. Cutting the plastic should be no big deal. I may even go bobbinless. I am also thinking of making a tall/skinny driver that can possibly fit up against the neck between the heel & the pickup. But first I just need a working driver.

Oh well...many people have had to make a few drivers, each get a little better...I've made about 60 through all this, some of the early hex designs looked particularly bad, and some took days to make...and didn't work at all. One of the tricky things about the Hex designs that eventually evolved is that the little "elements" I used were modified electronic components that were never designed for the kind of power that I was putting through it...they just burnt out! So, I set them in a metalic epoxy putty that acted as a shield and as a heat sink. The problem was, that I couldn't test them till I made them...so there were a few failures...don't worry about it, have a little faith and try again...the wire is pretty cheap and a roll should have enough fro a few of them...

Still...a tall thin driver wont work I'm afraid...been there done that...not worth repeating. The benefit of the thin driver is not only that the magnetic field is condensed into a small space, but there is a lot of wires overlaping, each wire generates a field around it with the current flowing through it (the polarity depending on it's direction) and that is wound around another and the fields build up magnetising the core directly under the strings. A tall thin driver will not have the same amount of overlapping wire and will lack the required speed I fear.

Custom 22...ok, you may have to look back a bit...first just try building the basic thing before you get to involved in switching, etc (pulling the battery will turn it off ) You connect the hot and ground wires to the input of the circuit and to the controls of the guitar as normal. The fetzer valve has a high enough impedance to stop the pickup being loaded allowing the signal to be split without killing tone.

Heh. It makes for a cool effect though, my 10 watt amp was rattling the strings like mad today. But seriously, you wouldn't want the strings to bounce the fretboard no.

Unless you developed such a light technique that you wanted the notes to swell up and they were cut short before the string rattling took effect...that's when you want that power. A light touch is an essential technique for getting the most range out of the device. You can get fairly cool reverse effects (slow attack, increasing volume and sudden decay) with such a technique.

It was pretty impressive though, the EMI rejection really cleaned up the signal. Ferocious little bugger too (okay that was probably the amp). I'm curious to see what results Col comes up with. Should give us a better idea of core thickness and spacing too. Mine are 2mm wide with 4mm between them (did i say it's tiny yet? )

Well that seems to be acceptable for the thin core idea to me...my whole core is 3mm wide. Still, a different beast. Both you and Spazzy (who I don't want to leave out of this development) have shown some proof of concept with the rail driver and I think it is more approachable and a better idea than the bi-lateral design...at least for DIY and my "thin coil" ideals...

Oh PSW, you seen this yet? http://www.vellemanusa.com/us/enu/product/view/?id=521723#

Velleman is actually a belgian company. A former teacher of mine worked there.

I haven't seen that one but the one I got the other day was from Kemo which is german perhaps. We have Vellerman here too! That one though draws way to much power (as does mine) for batterry operation. Amazing how much of the whole amplifier is now inside a single chip...One of the ones I quoted before has digital volume and mute switching on an 8 pin package.

Got to run now...got a dinner date with my lovely daughter...see ya later... pete

[col]

...EDIT: >sigh< so I think my recycled single coil driver is a bust. My Ruby circuit seems to work just fine, I think there is a fundamental fault in my driver design, I'm just not sure what. I'll have to try it again later. Oh well.

At least you know where the problem is - that's a positive development.

I've already got some steel that I can use for a rail design, it just needs to be cut to size. Cutting the plastic should be no big deal. I may even go bobbinless. I am also thinking of making a tall/skinny driver that can possibly fit up against the neck between the heel & the pickup. But first I just need a working driver.

Pete says that tall and thin doesn't work, and he has more sustainer building experience than the rest of us put together !.

I think you should try it out if you want but only after building a driver to a design that is proven to work - so start with a thin (short) driver. When you've got that sorted, start getting experimental

Anyway, good luck to you all, and thanks Col for posting your schematic (such as it is). I'll have to breadboard it at some point and try it out.

I've posted some more info on mods and tweaks to my circuit on the DIYstompboxes forum

I have got a bit further with the design - its getting smoother round the edges.

If you do decide to build it, post here, and I can tell you what the latest changes are

Col

[axe_2_grind]

EDIT: >sigh< so I think my recycled single coil driver is a bust. My Ruby circuit seems to work just fine, I think there is a fundamental fault in my driver design, I'm just not sure what. I'll have to try it again later. Oh well.

I've already got some steel that I can use for a rail design, it just needs to be cut to size. Cutting the plastic should be no big deal. I may even go bobbinless. I am also thinking of making a tall/skinny driver that can possibly fit up against the neck between the heel & the pickup. But first I just need a working driver.

Oh well...many people have had to make a few drivers, each get a little better...I've made about 60 through all this, some of the early hex designs looked particularly bad, and some took days to make...and didn't work at all. One of the tricky things about the Hex designs that eventually evolved is that the little "elements" I used were modified electronic components that were never designed for the kind of power that I was putting through it...they just burnt out! So, I set them in a metalic epoxy putty that acted as a shield and as a heat sink. The problem was, that I couldn't test them till I made them...so there were a few failures...don't worry about it, have a little faith and try again...the wire is pretty cheap and a roll should have enough fro a few of them...

Still...a tall thin driver wont work I'm afraid...been there done that...not worth repeating. The benefit of the thin driver is not only that the magnetic field is condensed into a small space, but there is a lot of wires overlaping, each wire generates a field around it with the current flowing through it (the polarity depending on it's direction) and that is wound around another and the fields build up magnetising the core directly under the strings. A tall thin driver will not have the same amount of overlapping wire and will lack the required speed I fear.

Cool, thanks for the info...that'll hopefully save me some time on experimentation.

At least you know where the problem is - that's a positive development.

Yeah, the driver was putting out something, so I know that the circuit definitely works. I just need to make a better driver. And my bassist is willing to machine the parts for me. He has access to a machine shop, and can do things with a lot greater precision than me. He too seems to have a great deal of interest in this project, so he and I have been talking alot about this. He also suggested I test the currents & voltages on the board, just to be extra sure that the circuit is ok. Not a bad idea.

Does anyone have a table of readings for the fetzer/ruby circuit? Runoffgroove doesn't seem to have one.

Edited September 21, 2006 by axe_2_grind

[psw]

Have you tested it with a speaker yet?

[col]

Does anyone have a table of readings for the fetzer/ruby circuit? Runoffgroove doesn't seem to have one.

(correct me if I'm wrong) the 'Fetzer/Ruby' is not really a ROG design - it is a Frankenstein circuit made by chopping and splicing two of the ROG designs...

As pete suggests, if you attach the output to a cheapo 8ohm speaker and the input to your guitar, you'll soon know if the circuit works

Col

[axe_2_grind]

Well I tested it with a headphone speaker, and damn near blew the thing up (the speaker that is)! But I have not tested it with a proper 8ohm speaker yet. I'll have to hook up one of the speakers from my amp and try it.

[psw]

Well I tested it with a headphone speaker, and damn near blew the thing up (the speaker that is)! But I have not tested it with a proper 8ohm speaker yet. I'll have to hook up one of the speakers from my amp and try it.

Well if it made a guitar noise it is probably ok...if it made some weird shreiking, perhaps not!

I would think there is still some chance of building a driver out of the single coil though. I'd go with the blocked up model. Have the pickup as normal but block up the lower half of the bobbin with something (cardboard would do) leaving about 3mm to wind on at the top...

This is how primal made his and seemed to work out ok....(can't think why his circuit failed after working so well though!)

pete

[Primal]

Pete, it was most likely just a bad component. I'm holding off building a new circuit for awhile in hopes that col comes up with a circuit that he likes (I like the ideas behind his circuit, and I know I have plenty of room for a larger circuit like that in my guitar).

[col]

Hey Pete (or anyone else for that matter), did you ever try potting one of these drivers in wax like many pickup manufacturers do ?

If that would work, it could make driver construction MUCH easier !

The only issues I can think of are that The driver being powered is going to be too much for wax wich is way softer than hardened epoxy.... and that some heat build up in a driver after prolonged use could soften the wax enough to make it useless (I doubt this - assuming the driver is not faulty).

I'm bringing this up now because I've just spent the last couple of hours winding two 4ohm coils... potted in epoxy. It's a horrible job. Potting with glue means that any error - e.g. leaving the wrong length of wire for soldering the leads to... or forgetting to pre-prepare part of the sequence of tasks... means getting sticky toxic gunk everywhere . Needless to say, thats what happened to me .

Not to mention, if you mess up and the coil is a dud, salvaging the parts is much more hassle.

anyhow, thoughts on potting in molten wax ?

and fingers crossed for these two new coils that are currently sitting setting.

(that glue seems to set real fast until you've finished building the coil, then it slows right down)

cheers

Col

[spazzyone]

All of my home made driver's got a little warm. But im pumping alot more power

So i would stick with the glue or epoxy. you may not have that problem

but if it got a perfect driver i would hate to lose it from "soft wax"

Like anything related to guitars it just takes time. look at Pete....time

but thats just my thought. Oh and im working on more sounds still.

I cant get a good clean level from direct so those sounds will be miked

you'll be able to tell its the sustainer and not controled feedback though

and dirty sounds ill use Revalver and go direct

[psw]

Hey Pete (or anyone else for that matter), did you ever try potting one of these drivers in wax like many pickup manufacturers do ?

If that would work, it could make driver construction MUCH easier !

Wax is a little dangerous to work with. The driver's can get a little warm but if taped up, wax would not be a problem. I just think that the PVA is just as good and a little more "solid" - not like epoxy solid, but plenty to restrict vibration. It may soften a little with heat, but it is cheap, safe and does the job. You can also wind the coil with the potting ensuring the glue gets in everywhere...can't do that with wax. Post-winding potting is going to need a vacumm pump I suspect. Some pickup guys soak their pickups in varnish for a few days!

Possibly the use of talcum powder mixed with the glue could bulk it up and stop it shrinking from the windings as it drys. I kind of liked getting messy with the glue...epoxy is another story...as Tim has found out...it either works or it doesn't. At least PVA wont eat the insulation or strip it with heat expansion...just some thoughts. Personally I'd use PVA and encapsulate it into a neat epoxy molded cover when all is done for a neat finished product...we'll see when I make my next one what I can do...

I cant get a good clean level from direct so those sounds will be miked

you'll be able to tell its the sustainer and not controled feedback though

Looking forward to it...while we are working on developing the rail idea in a driver format, it is interesting that, even if it takes excessive power, a standard pickup appears to work...something to think about. If a circuit could be designed to drive a pickups impedance efficiently, how much power would really be required....hmmm

I'm bringing this up now because I've just spent the last couple of hours winding two 4ohm coils... potted in epoxy. It's a horrible job. Potting with glue means that any error - e.g. leaving the wrong length of wire for soldering the leads to... or forgetting to pre-prepare part of the sequence of tasks... means getting sticky toxic gunk everywhere . Needless to say, thats what happened to me .

Yes...but you won't have that trouble with PVA!!! I kept well away from epoxies for this kind of prototyping. PVA will work unless you are relying on it to hold the thing together as in a bobbinless coil. I did find that the layered and glued card, reinforced while winding to be perfectly ok and held up a bit better than my plastic topped bobbin on my guitar in many ways (the potting glue sticks to it).

Pete, it was most likely just a bad component.

I think so, there shouldn't really be a problem with the reliability of the circuit...well I hope not...my circuit has run for well over a year now with no problems

keep trying... pete

[Primal]

Col, I potted my coil in wax and it works perfectly.

[col]

...Possibly the use of talcum powder mixed with the glue could bulk it up and stop it shrinking from the windings as it drys. I kind of liked getting messy with the glue...epoxy is another story...as Tim has found out...it either works or it doesn't. At least PVA wont eat the insulation or strip it with heat expansion...just some thoughts.

I think pva will always shrink when(if) it dries no matter what you mix in there.

Thats one advantage of epoxy - no evaporation = no shrinkage

I would steer well clear of 5 minute epoxies - they get hot, smell bad and can really damage your skin... The slow setting stuff seems a more useful - it doesn't seem to heat up - if you get it on your hands, you don't get the burning reaction that you can get with the rapid stuff... and of course you get about 2 hours before it becomes unusable.

If a circuit could be designed to drive a pickups impedance efficiently, how much power would really be required....hmmm

I don't think this is going to happen. You need current to generate decent magnetic force in the coil, and the relationship between current, voltage and resistance means that you need loads of volts to get a reasonable current through such a high resistance. Pumping a high voltage into a big resistor generates loads of heat which is very inefficient.

The big advantage is that using a pickup as a driver wouldn't have the same EMI/transformer effect that massively distorts any bleedthrough from the driver to the pickup in the 8ohm drive setup, but I don't think you could use a battery for power (maybe a car battery in a backpack ), and you also have the problem of designing a high voltage driver circuit and guarding against overheating.... (I wouldn't want to use a normal guitar poweramp for fear of damaging the output transformer ?)

If we can deal with the EMI problems, I think the 8ohm version has the advantage.

I wonder if it might be possible to go the other way and use a lower voltage supply !

many of the newer power amp ICs can run from 5 or 6 volts. What about a class D based system running from 4 lithium AA cells (just dreaming of possibilities)

Col

[col]

Col, I potted my coil in wax and it works perfectly.

Cool, might give that a whirl next time

Col

[axe_2_grind]

OK, so I removed my circuit from my guitar, soldered on some jacks, packed it up and headed down to the studio and plugged it into my 4x12 cab (8 ohms of course). The results were a little dissapointing.

It seems like the harder I hit my strings, the more it clips. But also, when it clips, it gets loud for a split second, and then soft again. I tried messing with the gain and volume, but could not get a decent sound ot of it.

I did notice, however, that some pieces of solder had broken off in the box I transported it in. So I may have to go over it again anyway. I do have plenty of spare parts to build another (with a tighter configuration this time). So back to square on for me. But i'm surprisingly not bummed about it. I enjoy the process, and each time I have learned from the previous experience. So the next one will be better. It's gonna be awhile before I get the parts for my next driver, so I have time to build this circuit over again.

Cheers!

[psw]

But i'm surprisingly not bummed about it. I enjoy the process, and each time I have learned from the previous experience. So the next one will be better.

That's the attitude...

Sounds like you may have got a little ahead of things if the circuit was already in the guitar. I strongly encourage people to take this in stages and don't get too far ahead of themselves...

This should be an enjoyable experience of learning and discovery...and you should end up with a working sustainer, eventually! If you stick with it, and stick with this work, you will be able to learn more and improve it as you go...AND...you will be a part of this progress...

So everybody's happy, everybody wins...

For instance...although I have a good working instrument...I'm keen to make an even better driver, build another circuit, and try different configurations... All this can easily be done...just swap in a circuit, or change the driver in the working guitar...

I have a feeling that something like col has come up with is actually of benefit and points in a new direction, I have some ideas of a different version of what I'm doing that I've had for a while... What I'd really like to try is a mid coil driver in a strat... Some kind of rail EMIbucker is perhaps the way to go... Then there is the posibility of running a rail in stereo, offset magnetic fields (bi-lateral magnetics on a full width rail driver in stereo anyone?), all kinds of neato ideas...just off the top of my head... Who knows what someone else could appear on the scene with!!!

Anyway...this thread is going gangbusters at the moment...there will be a temporary time when I am off the air when moving house in the future, so it will be interesting to see when I return if we get to 120pages or something...we have passed the 60,000 visits and 1,600 post mark and climing rapidly...imagine if we had a working product to hawk...hahaha...

pete

[col]

EMIBucker? news:

I built it, the coils work (one is 4ohm, the other 3.9)

After my first trial, the results are inconclusive. There still seems to be a fizz in the background, and I think it's EMI fizz. I will do some more testing to see if there is a reduction compared to my single coil driver.

It does seem to be a more efficient driver though, works my E string better and even with 14mm between the rails, there is not obvious note cancellation (again, more testing is required) - this adds more credence to the idea that wide driver cores will not be a problem.

col