Jump to content
psw

Sustainer Ideas

Recommended Posts

From my own experiments with a homemade sustainer, I split the output of my guitar to 2 amps. One amp (one of those little plastic fender amps powered by a 9v battery) drove the neck pickup of my guitar in place of its speaker. I never carved the amp up to make a contained circuit in the guitar, but it worked great. The prototype, if you will, was a mass of aligator clips all hanging out from under the pickguard.

From the sound of it, you've come up with the same idea but by actually building your own amp.

Is there any particular reason that you HAVE to have 6 discrete pickups, one for each string? It seems more efficient to have a single coil or a pickup run in reverse to create the sustainer unit.

Share this post


Link to post
Share on other sites

You only need six systems if you want to sustain multiple notes - if all you want is single notes, then it's not a problem, but for instance if you wanted to play chords with infinite sustain, you would need a separate system for each string. With a common pickup or driver, you'll start out sustaining all the notes, but the system will quickly settle down to the note or harmonic closest to the resonance of the system, and the other notes will die out. Try it by pulling feedback from an amp - a chord quickly becomes a single note, usually a harmonic of the most dominant note in the chord.

Share this post


Link to post
Share on other sites

Oh, okay. I'm with the program now. I suppose there's a place for both types. I played a guitar synth many years ago and it had a sustain system for each string. It was pretty freaky because you could hold a chord on a few strings and tap like mad on the other strings to play a melody. Serious drool factor. The only problem was that the guitar weighed a TON.

As for the single driver and sustainer coil, that would emulate the sound and feel of playing with a loud amp at low volumes. It's a more "guitaristic" sort of feedback that we've heard since the 60's.

Share this post


Link to post
Share on other sites

Well Jehle thats interesting. :D

I kind of thought that the pickup might self destruct by carrying the amplified signal.

I know Micheal Brooks Infinite guitar uses a seymor duncan PU to drive his guitar though.

Can you give me some more details. Was the driving pickup single coil or humbucking? Particuarly powerful?

Anyone got any thoughts on why the sustainiac, fernades and floyd rose kramer systems are so complicated and expensive if this idea works just as well?

I'll give it a shot. but it hadn't worked for me before (perhaps I wasn't doing it right back then).

Perhaps a hybrid where you have individual driving coils for each string but taking the signal from the guitar's pickup with filters and power controls tailored to each string and frequencies is the go.

great contribution!

psw

Share this post


Link to post
Share on other sites

LK

Just discovered a short or something in my test coil and the other that I tried, a "magnetic piezo" is an experimental idea that was not magneticaly uncoupled, or uncoupled enough!

I see what you mean but If they are that close together in the Ebow surely their will be some magnetic coupling?

Anyways, I'll do a more reliable test in the near future and hope to be as pleasantly surprised as I was before in ignoring the phase problems that apparently aren't of as much concern as I thought! :D

psw

Share this post


Link to post
Share on other sites
The next stage is to make a multi-string driver to fit in a strat cover for the centre position. I might find that a larger coil, or multiple coils cause even more radiation so I have come up with a kind of humbucking configuration and various focusing plates and shielding ideas if I run into problems.

Can anyone think of a way of using the same coil to both pickup up and drive the string or am I expecting too much. :D

You're basically re-inventing the Sustainiac magnetic sustainer/Fernandes Sustainer/Michael Brook's "Infinite Guitar". Split the output from the bridge pickup, take one of the outputs, amplify it and pump it through the neck pickup to drive the strings.

The key with the Sustainiac/Sustainer (Michael Brook keeps his a closely guarded secret) is that the bridge pickup is being used to power a driver in the neck position. Sustainiac is very clear that you cannot use anything other than the bridge pickup as the source (humbuckers are recommended), and you can't mount their driver anywhere but the neck position, because of the interference you describe.

Is there any reason why you can't just use a regular pickup as a driver for the neck position, rather than building one from scratch? Just pump the amplifier's output through the neck pickup.

Share this post


Link to post
Share on other sites

I think he's looking for something with a little more functionality, Darren. Jehle points out the obvious limitations of the systems you mentioned, and psw is taking the next step. Besides, building a better mousetrap is its own reward, right? :D

You can use a pickup as a driver, but it's not very efficient, since it was designed as a pickup and not as an electromagnet, and the wasted power is dissipated as heat, causing other potential problems. Ansil mentioned using relay coils for drivers, since they'e designed to do the same job. I think a similar coil is probably going to end up being the best driver, something with heavier gauge windings that will induce a stronger magnetic field, but that remains to be seen.

Share this post


Link to post
Share on other sites

Your right about the mousetrap alright LK B)

The ideal configuration that I'm aiming for is:

a drop in replacement for the centre coil. Preferably with the drivers, sensors and ciruitry in the same unit.

I'd like to run it from a rechargable battery (i'd put a charging socket on the back plate).

I'd also like to put the control switches as miniture push buttons on the ends of the pickup (an idea Ive been using for new pickup designs for phasing and voicing made possible by the use of miniture RE magnets and changes in coil design)

I'd like to have it run more efficiently than present devices (am exploring half wave amplification in this regard) [ p.s. your right about the S+H idea SK. I think but there maybe simpler ways, perhaps a high speed flip-flop]

I'd like to address the polyphonic problems associated with the present designs

I'd like to see the centre coil still usable as a passive device when the sustainer is not functioning. I'm thinking of combining the driving and sensing coils to achieve this.

I'd like to set the whole thing in epoxy so none should know the secret of how it works! :D

psw

Share this post


Link to post
Share on other sites

Actually I live the inbetween sounds but it has to go somewhere!

It is also a comprimise position. As LoveKraft pointed out, it is easier to drive the string nearer it's centre. But too far away and I anticipate problems with string bending.

Also, some guitars only have two pickups, the bridge and neck PU's are by far the most used and really I only use the middle PU to colour the sounds of the others.

Out of interest : I have a crap strat that I've done up with phase switching for each PU and a three way toggle like a gibson on the lower horn. This gives me N N&B B with the N&B position preset to in or out of phase for a wide variety and easy changing. The centre tone control is used to fade in the centre PU (in or out of phase) to color the sound. I find it a far more effective control than a standard tone.

psw

Share this post


Link to post
Share on other sites

http://www.geocities.com/austenfantanio/we...aqsustainor.htm

faq on my sustainor for all those who had questions on mine

Share this post


Link to post
Share on other sites

:D

Hey Ansil, good to see your keeping up with this topic!

I've got to thank you for getting me on to the simplicity of your 386 amp circuit for your sustainer mod.

Can you tell me the purpose of the input capacitor. I've been using only the output capacitor to great effect but my DIY electronics theory is a bit iffy!

Perhaps you can enlighten us on why electromagnetic sustainer circuits, as described in the patents, are so complex.

Also, do you, or anyone else, think that it is possible for the driver and sensor to share the same magnetic field (say in a stacked configuration) or is it going to oscillate wildly by definition?

psw

Share this post


Link to post
Share on other sites

well psw to answer your first question the input capacitor i put in there cause i got a ton of emails from people who started talkin about that it needed one and i was like hmm ok sure if it will please the masses, theoreticaly it doesn't but sure whynot. since i am used to building pedals now i pretty much encorporate it into all of them by default anyway.

as far as them being complex i couldn't vouch for that for some reason i can't few the pictures in the patents even when people include the links no computer i have had access too at all wil show the picutres.. the one person who did send me a pdf of the sustainor wiht a good pic was a rockman sustainor.. which i needed too.. so i couldn't answer if somone wants to past the info in a pdf or something and send it to me. feel free and i will look at it.

as far as sharing the same field i haven't thought about it.. personaly i would say it would have to be expiramente as most of the stuff i do is from trial and error.. lol

funny thing is.. i found out that microphonic pickups work better on this feedbacker sustainor thing. i am sorry everyone has had so much problems with it. i am baffled really.

it all started with one of those sears guitars [yes the big catalogs] my buddy had one, and my little brother got onesome time later. i purely hated that thing. but one day after munkying with the input jack that determined if the speaker would come on when it was plugged into an amplifier i started to get this groovy warbling type slow oscilating feedback that started creeping up. after some tinkering with it. i got it down pat using the tone control as my drive knob for the speaker. and plugging into a regualr amp i had this wildly controlable feedback. took a little gettingused to but it wasinteresting none the less..

now i have taken a step further i have gone the boss route using the 4046 chip as an octaved mulitlplier. i was lookin at the article mark hammer had on his website and decided [after playing this cool radioshack keyboard that had a feedbacker sound on it that i love] i would try to do a pedal version of that for myself. basically it takes and mulitlplies the octaves up and i have different dividers for it after wards. but what it does is u hit a note with a mild distortion type sound.. and the longer you hold it acts kind of like a messed up comressor it starts feedingback this note that is presetable but moslty ihave only gotten good results with one octave up. and well it gets a little fuzzier the longer you sustain the note..

its too complicated to go into now, as i am still working out each section on a bread board piece by piece.

but for basics on what iw as doind check out this article.

http://ampage.org/hammer/files/Marston's4046circuits.PDF

Share this post


Link to post
Share on other sites

Ansil, that sounds interesting! Is it like the Boss feedbacker Distortion? :D The schematic is around somewhere on the web. If so, is the feedback note synthesised and monophonic as the Boss appears to be?

PROGRESS REPORT

Meanwhile......

My little sustainer is still going. :D

I've set it up on my test guitar with double-sided tape (the inventor friend) and croc clips.

I found that the coil is more effective when the magnet is placed below and attached to metal (in this case the end of the truss rod!). People following this thread will know that I am using a ferrite core. I might try an iron core as it may be more effective after all!

If the string is bent off the centre of the coil, away from the core, the feedback dies away. As it is in the neck position, any string bending is effected in this way. Perhaps some sort of blade configuration maybe necessary but problematic as I'm still going with the six coil driver - any thoughts guys?

The driver causes the string to vibrate vigorously in an up and down motion - not the guitars natural circular manner - causing the string to rattle against the frets. This does cause some really cool changes in harmonic feedback and doesn't prevent the note from sustaining but is not ideal. Anyone got any thoghts on how to get the string to move from side to side? This is the motion initiated by a violin bow.

My 9 yr old came in and played with it. She said it sounded like an accordian! :D What would she know. She plays violin, but sometimes she has the tact of a drummer B)

I've tried puting various caps on the input to no great effect so am leaving them out for now.

I still can't get it to run ebow style. Ive tried hooking the driver to a second pickup, out of the signal chain and get plenty of squeels and interferance but no sustain. Why, I don't know, but it only seems to be driving properly from the bridge pickup that is connected to the signal chain. It will do this even with the amp turned off so I don't get it.

The ebow patent suggested that the driver and sensor could be one and the same! I am having trouble coming to terms with this idea. Anyone got any thoughts? (LK?)

Ansil. Can you tell me how to get more range from the sustainer mod circuit. I'm finding that I can't get the control of gain that I want. I'm using a 1k trim pot. I want to be able to reduce the output further but retain the present max out.

Anyhow, the quest continues..........

psw

Share this post


Link to post
Share on other sites

actually the syntehsized note is not that bad sounding on what i have right now i am still workin on the tracking right now. what i did was use the theory from a few gurus at diy stompboxes

see if you multiply the guitar signal super high and then divide down from there you get better sounding harmonies

its still up in the air and well it will be for a while casue when it pisses me off i rip itapart and build somethign that amuses me.. lol

i only have the one breadboard at the moment but thats ok i am geting it..

Share this post


Link to post
Share on other sites

Ansil, Keep working on it! Most people prefer a stomp box to a purpose built guitar so it will probably be more acceptable.

What I'm trying to achieve is an add on that offers a huge range of natural techniques to the guitar itself, simply, cheaply and with as little modification as possible.

Perhaps you can help with this. I need to put in a switch so that, when the driver is activated, only the bridge PU is connected.

Also, I have a neat little encoder "pot" with a push-push switch. I know this is getting into digital territory, but has anyone tried using this type of control for effects and stuff and would it have a place in this application do you think?

Also, I'm looking to build in some simple effects into the driving chain (tremolo, etc). Has anyone got any thoughts on this? Early experiments with a flanger were really weird!

Ansil, since your looking at synth type stuff. Perhaps there is a place for it in my type of sustainer. Consider this, a synth note generated from the played note, driving the string. The string would feedback with characteristics of the synth note would it not? Just a thought, what do you think.

thanks

p s w

Share this post


Link to post
Share on other sites

The sustainer is still going on it's original battery! (Not continuously of course)

So my next prototype is for all six strings and has a coil only 3mm thick. My idea is to make it small enough to tape to the scratch plate, not replace pickups or to invove routing the guitar.

The present prototype works well but vibrates the string up and down only. This causes the string to hit the frets. I would be interested to hear is anyone has some ideas to vibrate the string more from side to side, or round and round as it naturally would.

Also, a little less technical. How or what controls would people suggest for it.

You could go simple with just an on off switch. A phase switch. An adjustable sensitivity control, perhaps on a sliding pot, some internal effects on the drive signal, LEDs ?

cheers

psw

Share this post


Link to post
Share on other sites

It pushes and pulls. I thought of driving it with a half wave amplifier but I believe that the constant positive charges in the electromagnet will effectively produce a static magnet as the core won't have time to demagnetise between pulses. The negative cycle of the AC signal speeds this demagnetisation process.

I could be proved wrong and so have experimented with ferrite cores as, although they take magnetism well, they don't hold it as well as iron and so are theoretically more responsive.

The current working prototype is a hollow ferrite core and works well and may have addressed some of my concerns about phasing mentioned in earlier posts and in all but the ebow patent on electromagnetic sustainers.

My latest model is yet to be wound but has a semi-solid iron core and will have a wide coil and 7 magnets between the strings. The main coil is 2mm thick and will be wrapped with a secondary coil array at right angles to encourage some side to side or circular movement. I may need to incorporate a sheild system that I devised for pickups influenced by the LACE pickups to limit stray radiation.

thanks for your interest

psw

Share this post


Link to post
Share on other sites
http://members.shaw.ca/roma/sustain.html

Does anyone know anything about this?

its a compressor type circuit..

when the threshold gets too high the led lights the ldr drops resistance and then the overall signal gets weaker which causes the current to the led to be less so it shines not as bright and the ldr goes up in resistance and then there is more gain. so then the led will shine brighter and .. {this happens to fast for us to hear it so we perceive it to be smooth.} but personally i prefer john hollis's flatline compressor. its what i use when i had my rig up and running.

built a inverter based compressor around that too. hmmm creamy

Share this post


Link to post
Share on other sites

psw, just had a thought; if you use a hex peizo bridge pickup, you not only remove the magnetic interaction from the formula, you also add "acoustic" functionality to the mix with very little extra effort.

Share this post


Link to post
Share on other sites

LK : Unfortunately I don't have a piezo hex PU. Do you know of anywhere someone has made one. I've seen simply putting buzzer piezo's on the bridge but not hex. There maybe a problem with handling noise. You've probably seen my enquiries on that on other threads.

I still can't find a better access to piezo materials other than buzzers!

Coil prototype 1 has been the most successfull in terms of power and sensitivity. This may be a product of it's ferrite core, that it is only focused on one string, it is 4 ohm rather than 8 ohm,etc.

A major drawback however, is how directional it is. Because of the requirement to locate it at the end of the fretboard near the string centre, bending strings takes ithem out of the driving field. Also the driving force is almost entirely up and down resulting in the string crashing into the frets.

As a result I'm moving towards a design that operates across all of the strings and creates a movement from side to side. Coil prototype 2 seemed to achieve this but is a little rough. It utilizes a special core and magnetic "shield" which I call a "cage" which disperses the power of both poles of the magnets towards the string and in such a manner as to create side to side driving.

I'm up to coil prototype 3 at the moment. This coil is 70mm long, 10mm wide and 2mm thick! Ive developed a method of bobbin construction that is cheap and easy but winding these ultru-thin elongated coils is a bitch! One interesting aspect of this coil is that it is flexable so can be bent slightly to the string radius - cool!

This work may well lead to new PU design ideas as the driver is akin to a PU in reverse! :D

I noticed that if i hold a driver above the pickup all of the signal is cancelled out even if is being driven by another PU.

As a result -I'm making a duplicate air core of the same dimensions in the hope that, like a humbucker, the radiation of one will cancel the other, but, only one will have the magnetic energy to drive the string.

keep contributing as progress is being made!

psw

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×