Sustainer Ideas

[A Pet Rock]

OK, I'm new here, I've read quite a bit, now I'm going to ask for some help before I go too far down the wrong road. I'm trying to make an ebow type of sustainer for a single stringed robotic instrument that I've been trying to put together with an arduino. I've got all the stuff I need, the opamp, the breadboard, the capacitors, etc, and now its time for the inductors. I bought some wire from radio shack

Will this stuff work? Seems like it should if wound one pickup with the 22-gauge and one with the 30-gauge, I should be in the money... Is this stuff too thick? What sort of Inductance/resistance should I be aiming for here? I guess I should go back to radio shack and pick up that voltmeter.

Thanks,

JD

[A Pet Rock]

Oh yea, other questions:

What should I use as a spindle for the wire? What type of core should it have? Do I need a magnet on top of it? Where can I get materials? I'm eager to get this working as it doesn't look too hard, except for the winding.

I'm sick of paying postage for online shipping so other ideas would be welcome.

Thank you guys much in advance!

[psw]

Welcome JD,

It is a little difficult to know exactly what it is you are trying to do. A single string instrument played by an electronic robot...hmmm

Winding coils isn't difficult, building the "spindle' or bobbin to wind it on to takes some creativity.

Also, I am no good at wire "gauges", it is too easy to get them confused as there are different standards, use metric mm if possible. Generally 0.2mm is suggested, on a single string device, I am not sure, but the amp needs to see an impedance of 8 ohms so thicker wire is only going to make the coil have less resistance and so even bigger. I'd still suggest 0.2mm wire and a deeper coil (say 5mm)...it may/will take some experimenting.

For a pickup coil, most likely even thinner and many more wire turns...you may be aiming around 10,000 ohms, so the thinner the better, but this will be very hard to wind. The bobbin should be round as this is a lot easier to wind and it is only being used on one string.

You may consider taking apart some relays that have cylindrical bobbins and may find something that is high enough in resistance to act as a pickup. I did some work in this area. Otherwise, check out the DIY ebow at aron's stompbox forum...search here for a link and discussion, as I recall there was it's own thread and some discussion here about it.

You definitely need a multimeter to test the resistance of the coils.

Perhaps a bit more detail of what this instrument is could give you some more specific answers...it sounds like quite an undertaking and it is difficult to imagine what it is that you are trying to make...

pete

[A Pet Rock]

I think you've answered my question, 8 ohms and 10,000 ohms for the driver and pickup respectively.

The other stuff is definitely just background, that I think is interesting. Basically what I am doing is developing an instrument with servos and solenoids that is capable of being controlled by a computer. The ebow was chosen as our attack mechanism as there aren't any moving parts and if this is an installation art piece, it needs to be able to run without breaking for a duration of time. The instrument will either be fretted by a series of solenoids, or a stepper motor with a glass slide on rails. I was going to use a piezo as a pickup. The whole thing will utilize and Arduino microcontroller as the brain. The idea is that I could make an instrument that "listens" and responds to ambient noise in some ways. If I developed 3-4 one stringed computer controlled instruments, then the instrument could form chords and I've just imagined that the sound of a slide moving up and down 3 different sustained strings in some sort of controlled algorithmic counter melody could be quite beautiful to listen to and to watch.

I'm new to electronics, but I'm a pretty technical person, so I'm not to worried about the challenge... just the amount of time its going to take.

What is your source of capaciters and all that stuff? I've been ordering stuff off of electronic goldmine, and I stopped by radio shack. Radioshack doesn't have much selection, and is expensive, EG is unpredictable and shipping is costly. Hopefully in 4 months time when i have a working prototype, I will have something to show you guys.

[psw]

OK...I get the idea...and you seem to have deciphered my message also. If the pickup for the sustainer signal is that used to make the sound (ie to a guitar amp) it may need a preamp as well...but the pickup coil in this case need not be as big as a normal guitar pickup. As I say, look for relays to scavenge their coils already wound as pickup wire is hair like, expensive and difficult to work with.

Look back a few pages to a post where someone suggested a box separate from the guitar in which there would be 12 chromatic harp strings that would be activated by the sound of the instrument...kind of an electronic harp effect. A bit like an Aeolian harp (harp played by the wind)

One thing you need to consider is that once started, the strings will not stop. You may need to devise dampers...kind of like playing a piano with the pedal down.

I can think of other mechanical ways you may seek to excite the strings...what comes to mind is a hurdy-gurdy, which has a kind of rotating violin bow and push buttons...this is perhaps an appraoch you may be interested in for a robot. One that uses this technology is something like what was mentioned as a lot of strings, but perhaps activated by a recorded sound source, or triggered by an environment (say proximity sensors of the audience walking up to it) that in turn excites (and perhaps damps) a set of many tuned strings...this would give a sense of interactivity...the recorded sounds would only need be "heard" by the instrument to excite the strings of course!

I went to Melbourne's Museum recently and they have an installaion called the "living room" in which you walk around with 3D glasses on ans see these flying stick like things that join at the ends...as you approach or walk past, these "sticks" join end to end in complex 3D objects due to infra red senses hidden in the roof. So you can be standing there and all these things swirl around in your basic shape but someone walking past will "capture" some of yours and fly off to join there shape as they walk past....hypnotising. What I thought was especially cool was there was no explanation of it and many people, me included, took some time to see that these pretty colored flying "living" things were a kind of electronic reflection of our selves and the heat given off and reacting to everyone that was watching. I saw a child try and reach out an touch the thing and of course, as the child reached out, so too the 3D "thing" reached out to it. Eventually, even I couldn't hep waving and having splinters of the thing fly out into space, only to return or join with another object created by the sense of another watcher. (lucky it was a dark room!) They can do other exhibitions and more conventional films with the same equipment, so I imagine it will be there to stay...intriguing.

So....I have an appreciation of these kinds of things, I often think I should attempt something myself. In a vein to the above and combining your idea for instance, the slide could move in accordance to the proximity of a watcher...security sensors could be used. As you move left to right, perhaps the slide moves up or down, as you move closer perhaps the tuning changes (as on a pedal steel) or dampers are operated (so when no one is there, no sound is present). The result could be some interesting physical interactions with the thing where the audience is also the musician...if you get my drift...very John Cage!

So...yeah, the more you think about it, the more potential there is, but of course all of this would be a lot easier and not require "tuning" if the entire thing was electronic...effectively a theramin operated by sensors...but would it be as interesting or as interactive, as reflective or as educational...

Anyway...enough from me, good luck

Oh, yeah...obviously I am in Melbourne, Australia (at the bottom of the world) and so have different local "radio shack" like suppliers (dick smith, Jaycar, etc). Lots of things are available on line, but the postage is a killer, especially international...and sometimes you need to try a few things or rush out for another...or simply browse around for ideas. Over time you build up a stock pile of stuff like caps and resistors.

You have quite a task if you are going from little electronics knowledge to robotics in one fell swoop, but with determination and perseverance, lot's of things are possible...feel free to email me for more suggestions or advice, enjoy....

pete

[ghendrickson04]

A Pet Rock,

I don't know if you mentioned where you live, but I like in the US and I buy almost all my components from www.smallbearelec.com. Their shipping is really reasonable and their prices are much better than Radioshack. Even after adding in shipping costs, it's still considerably cheaper for most things.

Good luck. Your project sounds very ambitious.

-Garrett

[A Pet Rock]

Hey, guys, thanks for the help, and the comments. We'll see where all of this goes. Time is short, especially with a job. I'll keep you posted as the project progresses.

JD

[DCobb]

Hmm, is it possible to modify an active pickup like an EMG SA into a driver?

[psw]

no

[DCobb]

dammit, I'll leave sustainer fiddling out of that project then ty in advance

[DCobb]

hmm, does that mean an ebow won't work on an active pickup either? or does that work differently with the pickup?

[psw]

I was trying to be more concise in my answers because people get confused in my long windied explanations and diversions...I feel rather proud of that last post...damnit, now I have lost the flow...

No, ebows are not a problem as they have a pickup and driver within them completely separate from the guitar...I am not sure though how it reacts to an active pickup, because they also use the pickups magnetic energy to activate them (sort of) so that the volume increases as you move it towards the pickup.

EMG's are known for a low magnetic strength and so may react slightly differently, but otherwise no problem...

Pete

[mojoDodo]

hey all, i'm new to this forum. i'm glad i found it though, it's got so many things i can do with my guitar. being an electronic engineering student and all this stuff is just cool.

anyway back to my question. i've read some of the pages on this huge thread, but i'm not quite sure about one thing: does the driver need a blade iron core or can it be made using the little bobbins found in a pickup? And also, could i just use one of those magnets found on a guitar pickup with or without a core?

Also, i'm interested in making a circuit that will give me harmonics as well, if anyone has something i'd appreciate it. One last thing which isn't directly related, i'm thinking of making my own pickup but i'm not sure what thickness wire to use. anyone knows just reply.

[mojoDodo]

one other thing i forgot to mention, i'm interested in driving the sustainer with an amp that can give a harmonic output. if anyone has any designs please let me know, i'd love to have them.

[psw]

Welcome mojoDodo

i've read some of the pages on this huge thread

Well done, but better to read the shorter tutorial threads using the links at the end of my posts...

does the driver need a blade iron core or can it be made using the little bobbins found in a pickup?

Either, but the coil does need a core of some sort, just like a pickup.

And also, could i just use one of those magnets found on a guitar pickup with or without a core?

Well, yes you could use a pickup magnet, or even adapt an actual pickup to make a driver or mount a coil on top if you have one suitable...see the pictorial of how I have done this. But whatever way...you do need a core.

Also, i'm interested in making a circuit that will give me harmonics as well

To create harmonics, reverse the driver leads. The harmonics are created by the driver suppressing the fundamental and driving the upper harmonics...so a simple phase switch should suffice in most cases. You could create harmonics with filters and such too...I usually use a 100uF cap on the output which creates a harmonic bloom on the lower notes and drives the higher strings more consistently...so a kind of mixed mode. This is largely due to the circuit being biased to the treble and the phase characteristics created at guitar frequencies.

So a dpdt switch wired as a phase switch can create this effect and is the easiest way to start.

To me installing the thing is the difficult part...I have a particular problem with switching on multi-pickup guitars...so if you have the ability to design switching circuits, this could help the project a little more. As always I strongly advise everyone to build and test everything outside of the guitar (holding the driver above the strings) before attempting to install or modify the guitar or getting too advanced in the plans.

i'm thinking of making my own pickup but i'm not sure what thickness wire to use

I specify 0.2mm wire for the driver...which is easy enough to work. Pickup wire is literally hair thin and generally 0.043mm or something. There are lots of sites and threads on pickup making, you will need a winder too, as they can't be wound by hand...you can make acceptable winders with a variable speed drill, but you will need a counter as their are many thousands of turns and it will take some practice too...so I hope you have patience. Stew-mac have kits too...so check that out for more details.

Good luck ,welcome aboard and feel free to ask questions as required...check out the threads below though...

pete

[mojoDodo]

Hey pete, thanks for the reply it's alot of help. As for the harmonics, i do know a little about filters so i could probably get something on filtering to give more than just harmonic/mixed output, maybe some sort of tunable harmonic output. As for the phase switch i don't quite see how this gives harmonic output. I assume that the lead reversal you said is basically phase switching. Some help here would be great.

mojoDodo

[psw]

As for the phase switch i don't quite see how this gives harmonic output. I assume that the lead reversal you said is basically phase switching. Some help here would be great.

Ok...let's consider what this device does...

Basically, the strings are moving (to simplify their motion a lot) up and down in relation to the pickup. The pickup senses the metal string within its magnetic field by generating voltage changes within the coil...this is then sent to the guitar's amplifier in which the analogue of this motion is transferred to the speaker coil which moves this in and out in a similar way, it pushes air molecules along which get in our ears which pushes our own ear drums in a similar analogue to the strings motion.

Right, so this technology is very similar running in parallel, the signal from the pickup is amplified (by our mini amp circuit) then run through a speaker like coil (our driver) in which the string is vibrating within it's own magnetic field. The result of which is that this driver field becomes stronger or weaker, pulling at the metal string or releasing it...hopefully, in phase with the signal and the physical motion of the string. So, when the string is moving down, the driver is pulling it down, etc.

However, the motion of the string is more complex than this. Behind the note are secondary waves, or harmonic constituents of the notes. This becomes important to this question.

So, if you run a sustainer backwards (reverse the field by flipping the magnet or reversing the signal leads to the driver (or even the signal in to the circuit...but this becomes a little complicated due to a shared ground with the battery in most circuits)) what do you get? An Anti-Sustainer? After all, in our simplified model, if the string is pushed when it ought to be pulled, you will actually suppress or damp it's motion, right? (I have actually experienced this happen on some guitars)

Generally no...the circuit will suppress the fundamental frequency of physical vibration and start to drive it at a higher harmonic. Just as you produce a natural harmonic on an open string by lightly touching it at (say) the twelfth fret will suppress the fundamental vibration mode of the string, it will allow the octave harmonic to ring out...so when we have the device in anti-sustainer mode it suppresses the vibration to reveal the harmonic...

Now the mind games start, the string is vibrating now at a harmonic, the pickups sense this mode of vibration, send it through our amp and the driver tries to drive this harmonic as well...out of phase! So, now is it suppressing the harmonic it created and trying to drive a higher one still. In fact, generally, it doesn't and the harmonic of the original, often an octave or fifth or even an octave and a fifth...will continue once established.

What is incredulous is that it does in fact work by simply swapping over the leads with a phase switch. It was inevitable that it was discovered as until you hook it up and try it, you wont know which lead is which and you have a 50/50 chance of it coming out a harmonic via this method.

Where things can be let down is that these high harmonics are well out of the guitars normal range and out of the range most guitar amplifiers are built to amplify. Possibly why our amp doesn't continue to suppress these harmonics because they would be out of range of it's capabilities...I imagine.

So, one thing is to use a wha-wha pedal say to increase the treble and target these harmonics...this works well in practice. Compression, but especially distortion and fuzz help to bring up the level of the harmonics too...just in normal playing. I would not apply these generally to the circuit itself...as fresh fizz finally conceded

The exception would be filtering, just like a wha-wha type of circuit. With such a circuit you may well create interesting and effective harmonic effects by driving the higher harmonics stronger than the original vibration mode and perhaps avoid the system fighting itself over what note it is trying to drive, as described above. All kinds of potentials are there to explore I suspect, but making a device by simple means is difficult enough to start with, and obviously the first place to start.

A lot of people have come unstuck in trying to better the idea before being successful with the basics. Some have made this and taken it further, most notably col who pioneered on this thread a circuit with compression and a few harmonic modes (you can find it on here somewhere) and dual coil drivers for instance. Other's have gotten in over their heads and if lucky have been able to backtrack enough so that it works at all and give up on their ideas till after they get the basic thing working...others just give up, and others will no doubt keep flogging a dead horse. None of these ideas were 'bad', but if you try something you have to be prepared to admit when an idea, no matter how good it sounds in theory, may not in fact work...I have quite a few dead horses in my life that I should quit flogging come to think of it....hmmm, that just sounds wrong....oh well!

So...before attempting filters and such straight off or even building the thing right into a guitar, make a prototype and test it. If you do it in modular form, you can add filters and preamps and such to the components you have already built and tested and will have a working model from which you can improve things.

I hope that helps you and other's come to grips not just with the harmonic potentials of this device, but the way in which the thing actually works.

pete

[mojoDodo]

this definitely helps, i simply failed to realise the function of the circuit. i do know a thing or two about fourier theory, but it's good that you explained all this for the greater good. i agree 100% percent with you on the 'test before you install' mentality, i've had problems in the past too.

i do have an idea, though, about creating harmonics. i don't know if you are familiar with PLL's (phase locked loops), but one way of creating a tunable output is using one such circuit. a good thing with this type of circuit is that it has a feedback loop and allows for the incoming signal to be locked and therefore sustain that specific frequency. the only downside with this is that a proper good quality design costs a bit. a cheaper design can be made but i cannot guarantee the results will be respectable. now if someone simply wants harmonics of higher order, then a simple frequency divider can be used to emulate this. i know it's nowhere near what it really is, or what it should be for that matter, but i'm sure i could get something interesting out of this. i'll give it a try this summer and post with any respectable results. as for the PLL, this needs alot more work and design so, unless someone's already done this, i'll be trying out some designs see where it takes me. give me some feedback on what you think of this, i'd greatly appreciate it.

the lead reversal/phase switch method is not bad, yet it only gives a mixed output. with a PLL this can be fixed, giving true harmonic output, and in conjunction with the phase switch method you get a full sustainer kit. be prepared, though, coz PLL's aren't easy to build.

cheers, mojoDodo

[psw]

Well...if you are so inclined...a more pressing problem and one that has plagued me enough to personally abandon the thing for the time being is the installation and switching problems associated with any guitar with more than one pickup and perhaps particularly important for my own pet project and proposed commercial incarnation of this, the "piggyback" driver. It would appear that the solution lies in quite complex (at least for me) digital switching.

I did research a little into the idea of phase locked loops and have such a chip, but I am completely self taught and also have some doubts as to it's true value...at least functionally with this project. Still...prove me wrong, after all...I thought enough of the concept to explore it a little (but not in any practical way).

the lead reversal/phase switch method is not bad, yet it only gives a mixed output.

I am not quite sure what you mean by this. All notes are harmonic, but in keeping with all such devices, the harmonics are not always an octave in part because of the fixed location of the driver relative to the fretted notes in relation to it. I suspect that a filter method will prove to be similarly "handicap ed"...but these harmonics are in line with the harmonic series which gives them an interesting quality and strong relation to the original note that is very musical, and quite predictable on any given instrument.

I am glad you are receptive to testing outside of the guitar and I hope have taken on board the idea of working your circuits in a modular form. For instance, a poweramp stage, usually a LM386 is required. To prevent loading, some kind of preamp will be necessary. Compression is useful and col has given a good argument for forward feed compression for this particular application. Some filtering might also be advantageous too, especially for removing unwanted artifacts in the signla that may make the "fizz" EMI effects more predominant. There is also interest in D class amps, if only to provide better power consumption, but I don't think you will really want to go much above 1 watt in power unless to provide better headroom. So, making each part separately, getting the basic device working then modifying and adding will be the most productive I am sure.

Beware also that the thing will need to be able to fit within a guitar and run from a battery, quite often simple is best. I wouldn't be knocking the phase switch approach till you have tried it. Filter approaches may have very good results but may be specific to particular strings...so like my 100uF output cap, provide harmonics on lower notes, but good normal response on higher strings (my compromise position). So you may have to adjust the filter if it is very specific as you play.

Then there are all kinds of problems that can occur with inevitable phase differences between the drive and the physical motion of the string. As has been discussed and debated, one thing for sure, the coil and its reactions are somewhat a mystery, unmeasured or standardized and will alter over a range of frequencies. My thin coil design was designed through trial and error to address this problem and allow simple amplification to be used and seems to work pretty well. Why it does so is open to conjecture but the idea that the thing has a low inductance and so remains fairly stable at different frequencies sounds good enough to me. Similarly, the 0.2mm wire seems to work derived from the same means but 0.25 and 0.15 not so. But my single coil drivers is only the most simple of these too and you could go for various dual coil, or even six coil or more designs if you so chose with completely unpredictable results.

On the subject of pickup making, the driver is not a pickup but the principles are very similar and in reverse so if you get in deep with this stuff, you may well come up with an interesting take on pickup design and theory by approaching it from this different angle.

If you enjoy tinkering and discovering things, then this is a good place to be...but if you want anything but encouragement and my thoughts and ideas and those who also contribute...i.e. a fully realized one system meets all requirement...then perhaps not a project you might wish to engage in. Certainly post as there is an eager audience who just like to watch as the stats show...

pete

[mojoDodo]

Hey, so i've been looking around for components i need to make the fetzer/ruby amp for the sustainer, thing is though that i cannot find the required FET transistors in any electronics shop i know of. They're all n-channel FET's, and they're all general audio transistors, so i was thinking maybe i could just use any low voltage/current FET i can find. I searched and i found a low voltage/current MOSFET ( code: 2n7000) and is an n-channel enhancement mode FET. I am quite familiar with transistors, and i'm pretty sure this will work, i just need someone to basically confirm my choice. If anyone knows please let me know asap.

[psw]

I doubt I'd know any better than you on transistor choice, this always seems to be a problem with this circuit which is why I haven't used it myself and I have always pushed for someone in the know to devise an alternative complete circuit...

Anyway...I suspect it would work, since you are studying this stuff, perhaps you could ask your teacher, look up a susbstitution book ask the guy in the store, or more likely, give it a go. What I might suggest is with this component particularly, and maybe even the LM386 chip, use some socket strip. The pinouts may be different and Mosfets are notoriously easy to damage. Using some socket strip will allow you to easily remove the component if necessary and avoid damage due to heat. I have never fried an LM386 but if you use a socket on this one, you will be easily be able to remove it for use in a different circuit at a different time should you wish to.

Sorry, component choice and even this particular circuit is not my strong point. The reason I have not used the fetzer/ruby is that I think the "ruby" which is just a simplified version of the LM386 data sheet, could be improved with a 10uF cap between pins 1-8 and maybe a gain trim pot if you have powerful pickups and want more control. I also don't like the need to bias the transistor and the general difficulty of getting such components. Also, I was experimenting with this long before the suggestion of the fetzer/ruby came out. On the other hand, many have used the F/R and it has become the standard by default. ROG devised the preamp as a solid state emulation of a fender preamp stage (so they say), hence the name.

There is no reason to especially think that this is a desirable quality in this application. Basically, you are building a power amp (LM386) with a preamp to add a little gain and prevent loading at the same time. Other than that, the circuit does not contain any real mojo, so best to leave the "spirits" to the crucial driver construction where there does appear to be some!

Other than that, this is DIY I am afraid, hope that helps

pete

[mojoDodo]

Actually i always use a breadboard before i solder a circuit together. It's easy to use and everything comes off right away in case something starts overheating. As for the FET there's no way it could overheat as long as the bias current isn't too high, and in this case it's ok. The 100K POT will protect it.

My only problem is that apparently using a BJT rather than an FET will not work. I recall reading a post about this, although it did seem somewhat unusual. I assume whoever wrote that doesn't know much about amp design. BJT's will work just as well as FET's only difference being that the biasing circuit must be altered. In the case of the f/r the 1M ohm gate resistor will have to be removed if a BJT is to be used instead. This is only used for FET's where a voltage rather than a current at the gate/base must be provided. In the post the person was replying to someone who was having trouble with the circuit. Turns out he was using a BJT than the FET's listed. That person replied that the BJT won't work, so i just want to make that clear: BJT's are equally capable for a pre-amp stage.

Keep Rockin'!!!

mojoDodo

[darqdean]

If only you were here a lot earlier to point this out, this avenue could have been explored a little further. So, here is your chance, hook both the pickup and the driver coils in parallel and post your readings and results comparing the driver alone and the pickup/driver in parallel (definitely not series). It could even help with the switching woes. A whole area there to explore with a very simple connection of wires...

Well spotted...welcome aboard... pete

Well, it worked thanks for the suggestion

With just the driver connected I managed to measure about 80v pk-pk on the pickup winding, which was then picked-up by middle pickup and caused some really nasty and undesirable HF squealing. I connected it in parallel with the drive winding and low and behold everything was under control I've fitted a 4p2t switch (available >|here|< ) so that when I switch the sustainer circuit on the neck pickup winding is connected in parallel with the driver and in the "off" position it behaves like a standard pickup.

I also fitted some magnetic screening to the driver/pickup by wrapping a thin strip of steel three-quarters of the way around the bobbin, wrapping that in tape and then fitting a shorter piece to cover the gap. It is important that this screen does not go all the way around the bobbin and make a complete circuit as this will result in heavy currents being induced in it from the driver coil, which will serverely over-load the drive-amp. Connecting both these plates to signal ground also provides some electrical screening. Now if I set the drive to maximum and damp the strings I get zero feedback through any electro-magnetic coupling to the middle pickup - remove the damping and the strings sustain nicely.

[darqdean]

I wouldn't be knocking the phase switch approach till you have tried it. Filter approaches may have very good results but may be specific to particular strings...so like my 100uF output cap, provide harmonics on lower notes, but good normal response on higher strings (my compromise position). So you may have to adjust the filter if it is very specific as you play.pete

If I may interject my two cents worth...

The 'problem' of filters is that they are fixed frequency, so they only work for a narrow range of notes - a filter that emphasises the harmonics of one note will not work for notes that are an octave or two either side of that - it isn't possible to design a filter that would work across the entire range of the guitar since the harmonics of one note are the fundamentals of others. The other issue with them is that they phase shift by different degrees for different frequencies, thus affecting which harmonics the driver is trying to boost.

The 'simple' mechanical phase-shift switch overcomes all these problems since it uses the string itself as the 'active' frequency dependant component - the string can only vibrate at harmonics of the fundamental note and the driver can only drive the string at harmonic anti-modes, so regardless of which note is being played, the driver will always try and supress the fundamental note and boost the harmonics.

One way to achieve a 'blend' would be to mix the output of the bridge pickup with the inverted signal from the middle pickup - this would effectively suppress the fundametal note while allowing the harmonic difference between the two pickups through.

pete: if you email me your digital switching problem I could see if I can come-up with a solution for you.

dean©

[psw]

Good stuff darkdean...

Ok...so can you do a diagram for us of your installation in particular the 4pdt switching solution. I take it that the middle pickup is disconnected with the sustainer on. In fact any pics may be helpful.

I can be contacted by email. The problems with the switching is that, although I have a circuit and a comerial quality ultra thin pickup conversion coil, on the guitar pickup it is designed for (a stratocaster) I get on off noises (especially off) and the whole wiring is pretty complex and varies from one guitar to the next. As a semi-commercial proposition, it is probably not worth while. Also, a 4pdt switch can be bulky and it would be nice to be able to operate the thing with something like a dpdt which would also allow the potential for switch pots for instance.

So, yes I have halted work on it for now as I believe that some kind of switching or more innovative approach may be required. Perhaps you have found something, who knows, so yes I'd like to hear more. Basically the ideal would be to connect the all the pickups to the circuit and have a digital switching system control all the bypass functions. You would need it to be pretty small and simple I suspect to make it worthwhile. There may also be a need to have it so as the on and off bypass has some delay in it in order that you don't get a "thump" on switch off.

However, I have not tried everything and am a little jaded, so perhaps you have found some solutions where I have failed and the problem may be more easily be solved than I anticipate. So, a bit more detail is required as it could be some subtle thing that you have done to overcome the problems of installing on multipickup guitars if you have no such problems.

The main thing is that you seem to have got it working, proving that it can be done yet again! Well done, and congrats...

pete

Oh...I don't quite follow what you have done with the middle pickup, is this bypassed also when the sustainer is on, or are you able to use it. The ide of using it as a filter is interesting, but in all mine I get unwanted coupling with the middle pickup that makes it unusable and must be bypassed....

Edited May 29, 2008 by psw