Donovan

Update... I've now cleaned up this design and it is completely click free, noiseless, and working great, so earlier problems have been solved. The circuit is very customizable and if the "chopper" effect is so desired, it is as easy as switching input/output lines. The update came after this idea was called for again in another thread, linking to that thread, the schematic is available there... http://projectguitar.ibforums.com/index.php?showtopic=40244

Here is the draft schematic for the "cleaned up" version. The signal is now very clean, click-free and working great. As an option, swapping the input and output yields a clicking effect on each switch on/off that resembles a helicopter's rotor blades with the right accompanying effects and technique. Also, the resistor network (which is supposed to resemble a potentiometer *** I didn't have a pot symbol, Doh! *** ) and capacitor in the charge circuit are completely customizable to taste. The schematic is a free for all. However, please credit my work where applicable. Hopefully this is error free, but as I drew it directly from my breadboarded model, there may be inconsistencies of which I am unaware. Please bring them to my attention if they arise. Thanks.

I suggest doing some research and learning how these things work. It shouldn't take too long as the questions you are asking are pretty fundamental.

I would do some reading. Read about 555 timers. Google the 555 timer and you will find a bilzillion sites explaining how to set them up, many with convenient little calculators that you punch in some numbers and they tell you what the blink frequency will be.

Also go to www.allaboutcircuits.com and read as much as you can handle about everything that is the world of electronics, including LED circuits.

If that were the case, I presume that the clicking could be reduced by smoothing the transition slew between off and on using an RC circuit in there somewhere...? Or would the Vdrop of the LED cause a click when the ~0.7v transition is achieved? Never tried it myself, and never experienced noise from LEDs in audio circuits, so I presume the timer would be the culprit if clicks were introduced.

Anyway, that's a whole different can of worms. Tim37 hit the target first time.

Could be like you said, smoothable, but maybe not. Testing is on order. It mat be that the clicking is due to inrush current. If it is found to be so, I'd try minimizing the current as much as possible. Check out this thread from a few weeks ago. http://projectguitar.ibforums.com/index.ph...=39451&st=0

It may be also as you say that the clicking would be due to the timer. I ran into this while developing the variable kill switch. I was able to minimize the clicking, but not totally eliminate it.

On the converse side, I have aclipping circuit that uses LED's to clip. It is mounted in the pickguard and the LED's light when clipping occurs. This circuit does not click or pop, but this may be because it is masked by the distortion tones... but I don't think it's the case.

Anyway, only 1 way to find out what's going to happen! Try it.

If they are to be blinking, then you will possibly have some clicking on the on/off.

There may well be some kind of electronic " inclinometer" device...I suspect that you might have a digital readout kind of thing for various applications.

Ummmm... yes, read the posts that have passed.

If pots are making things a little dark turning down, a treble bleed circuit can help with that.

Not to go OT, but got a link to one of those, Pete? Thanks.

Check out this page for a great explanation of how and why wiring up one pot per pickup works. It just takes a specific pinout to avoid affecting the others in line.

http://www.stewmac.com/cgi-bin/hazel.cgi?a...reeinfo/fi.html

I have done this as an experiment with a guinea pig guitar to try it, converting both of the tones on a squier strat into volumes. If you don't wire the wiper as suggested, what happens is cutting one cuts them all. If you are going to do this, I believe equal and higher pot values (500K -750K) are a must to maintain equivalence from one pickup to the next as well as to avoid cutting high frequencies. My attempt was with 250K pots (the converted tones) and there is a less than desirable high end cut when rolling off the volume.

You could easily wire the final output to one tone knob as well.

It seems like it may need a mercury switch to activate/bypass it though, as it is affected by tilting two ways....

Not sure what you meant there. If you mean the switch would be necessary to activate/bypass the 2 diferent axes as in one X, one Y, then no, I think you just leave the other axis pins as unused. Or if you mean the Hg switch would be used to turn the whole tilt system on and off... I still don't understand. Do you mean in order to keep the range of motion contained? If that is the case, they do make different configurations with varying ranges of motion.

I would also include a switch to activate the fade so it's not always on.

Yes, I agree that would be a necessity. I believe that a DPDT would make short work of that aspect. Seing you mentioned that makes me further confused about theother comment I quoted.

There is another KAOSS pad (the newest one, in fact) that might suffice in this area. The KP-mini is pretty darn small and it's battery operated (with an optional DC plugin). it shouldn't be too hard to strap one onto any guitar without even cutting up the body. I bet you could even mount it in the body without too much trouble. The only issue is that it has RCA connections for the input and output. This is easy enough to remedy with converter cables, but if you want to put the unit in your effects loop rather than between your guitar and amp, you need to run 3 different cables to your guitar. That seems a bit cumbersome. I might still give it a try though (hooray for zip ties).

I'd be interested in following your progress and lending some support where it's within my abilities.

I hadn't seen that model. At $150, not bad, considering the list of effects. If I were considering this (which I would at some point, too many projects of other interest going as of right now), then I would probably gut the unit, install electronics/pad in the guitar with just the pad visible and screen/controls in the pickguard, run the guitar signal in (with a bypass switch of course) then run out, both channels, through a stere jack. That way, I wouldn't have a need of making it look like a Franken-guitar with a bunch of extra cabling, which is really not ideal. The salient question is, the dimensions of the unit itself, if they could be crammed inside a guitar. Anyway, what you'd have would be quite a specialty guitar. To many, the idea does not excite the imagination, but I've said it recently, I am a sucker for a novelty.

The foot pedal still seems like a better idea to me. Then you don't have to worry about holding the guitar just right to get the effect you want..

Good point. I hadn't realized the significance of that until now. I guess I perceived that the intent was for it to be for showmanship... dipping the guitar this way or that controlling the stereo effect, sort of a novelty. That's how the thread grabbed my attention. I am a sucker for a novelty! Anyway, even if that show-boating IS the original intent, you're right, the pedal could be synchronized with some pretend bodily dipping and such and then you would not have the effect working when you didn't want it to.

So, I guess it comes down to whether the need is functionality/practicality or just show-boating/novelty, right?

I've seen this on youtube.com a few times. I do think it is very cool as well. There are a few different kaoss units available now. Some are cheaper than others and they are not uber-expensive. I'd looked into the mod myself, but fell out of love with it once I realized you need to keep the base unit as part of it. I'd be more interested in being able to use the pad as a stand-alone with my normal effects setup. Hooking up a similar touch pad to an output that could control a pitch bender or stereo fader would be sweet as well.

They have many units with varied construction and functionality, some even 2-axis (tilt in 2 planes)... and yes, some employ digital inputs/outputs, others give an analog response. I would not mess with the digital ones without some deeper understanding of electronics, but the simpler ones, like the one I linked... check out the data sheet. What is does is allow a percentage of signal voltage through, in effect, a trim potentiometer, just like the drawing you posted. The point is though, that the Hg switch idea should be ditched entirely. Not because it wouldn't work, but it wouldn't work as smoothly. A mercury pot like your drawing would be a step up. A potentiometer is the best solution as it's an infinitely variable or very smooth solution. So, then the question becomes "how do I hook up a regular pot to achieve this?" Then the various ideas about weights and such come up. IMO, the prepackaged inclinometer (it's a shame we didn't invent it right here and now) is probably the simplest and best-packaged solution... at least that's my $0.02.

What if it weren't a mercury switch, but a mercury pot of sorts?

Like you have this semi-circular track made of something resistive, with one channel output on one end, and the other channel on the other. Then the other side of the track is just plain metal.

I dunno how you'd go about building something like that, but it's just an idea, lol

The only problem is that you get 50% volume in the middle, equally balanced between the two outputs. It'd still be a cool effect though...

It'd be a lot easier to just build a foot-switch to do this, since you'd just need a basic wah pedal with a pot in it, or a blend pot to get 100% output in the center.

If you want to use weights, you'll just need two equal weights(each enough to put torque on the pot, which could be something like half a kilo), something to drill a hole in the shaft of the pot(or some other way to attach the string to the pot), and some string. Kind of useless since it'll be so heavy, but if you hang the weights out of the bottom of the guitar it'll look cool =P

If you actually looked, the company I linked to about 3 posts above... this is exactly one of several models they use to do exactly what the original poster wanted. What you are describing is an electrolytic inclinometer, just one of several methods used to produce exactly the effect that is being looked for and more smoothly than any small number of mercury switches could ever do. It may not be as elementary as hoped, but still not rocket science and certainly not much more difficult than wiring up a bunch of mercury switches in succession.

Think about it... this is a novel idea for a guitar, but not for other applications outside of ther guitar. Cars, boats, Wii controllers, tons of **** needs to provide its computer system with a measurement of tilt angle for various reasons.

It is called "out of phase", but is really only able to be called anything when there is another pickup available to compare it to.

If it is the only pickup in the signal chain, then it should not matter and no, you will not hear a difference. But, where you will hear a difference is when that pickup is activated with another pickup simultaneously. Out of phase, this is how humbucking is achieved, but in that case it is not only a mtter of which lead is + or -, but the polarity of the magnetic poles as well. That's a simplistic explanation though, and I'm sure someone else with more knowledge on the subject can give a more in depth explanation.

The tan thing with flat screwdriver slot appears to be a potentiometer, perhaps setting gain or blending signals. The bulbous orange things are low value capacitors. The blue things are resistors. The original pic you posted... the arrow points to a reddish-orange glass component that is either a diode or a zener diode.

I built this auto kill switch which is is variable via a knob a few weeks ago.

See this topic. http://projectguitar.ibforums.com/index.php?showtopic=39940

To hear just some of how it could be set up, click on the link in my sig and cjeck out the "Helicopter Concept Experiments" clips. The rate of switching and "duty cycle are easily customized to taste. I've not put up a schematic as the originally interested individual did not reply with continued interest. Since, I've learned a bit more about electronics and switching to make this more effective as well.

No...I don't think so...not in my experience anyway...look at the pickup/driver things or how others have successfully converted single coils. Typically magnetic poles are alnico by the way, but if you really wanted to they could be pushed down with a vice or something. If the coil isn't good enough, better to pull it apart and start again...another benefit of PVA for potting...easily comes undone.

Does alnico have a similar appearance/feel as ceramic magnets or is it noticeably more metal-like?

Perhaps part of what happens is that the signal drives the string and kind of lets go...or at least, attenuates the drivers magnetic field with the strings caught in it's sway.The shape of the field may not be relevant to the "phase" much at all.

Perhaps. If only we could see this stuff!

Nothing will eliminate the risk of fizz, a clean signal is probably a better strategy so that any fizz that might appear is at least not unattractive and distorted. Another reason to conserve clean headroom by lowering the power requirements to run it.

Not sure I understand what you mean. I don't see the fizz as at all related to the signal being used to drive the coil. Should I?

I am not saying that the single coil is a better or even more efficient driver btw...but I am suggesting that it can be good enough to have minimal EMI and drive the strings quite hard, certainly hard enough.

I have been able to drive the thicker strings quite hard, but the B and E strings are not effective above about the 14th/15th fret. Also, I have never gotten a consistent fundamental mode or harmonic mode. I have been able to use 2nd order all-pass filters to shift the regions and harmonic around, but there is always a mix in some places, harmonics in some places, and fundamental in others, never just one solid mode everywhere. This is 100% consistent across multiple drivers, multiple circuits with different preamp and amp configurations and different host guitars. Always, I am accompanied by a good deal of fizz. When I dial the amp circuit back to where fizz is gone, sustain loss abruptly follows.

If you have made drivers...what has been the problem so far with the testing of them? You need to test them well away from other pickups if you have not completely bypassed them as in an installation (at least in my experience)...maybe yours are fine but the circuit or the installation is suspect...or maybe you are reaching beyond the capabilities of the simple version of the project (like avoiding rewiring and bypassing).

The problem has been consistency and strength on the B and high E strings above the 14th/15th fret. I have completely removed the middle pickups with no change in results vs. leaving the pickup installed and connected. Quite the opposite actually, I was able to get the same results using the middle pickup for the signal as the bridge pickup. I was originally using a test box with about a 2-3 foot in/out cable. All of my electronics were contained within a black box and I was building modular preamps, filters, and amp circuits as to easily connect/disconnect for testing. The results with this box were the same and when I brought my less than ideal results here, it was suggested then to ditch the box and do a direct install, biting the proverbial bullet. Again, the results are the same. I have fiddles with preamp gain, no preamp gain, 20X 386 gain to 200X 386 gain, driver distance to strings, signal pickup pole distance to strings, low pass filtering anything above 2kHz, all pass filters, half wave rectification, injecting all sorts of digital effects into the signal chain, all to no avail. I am at a standstill at the moment and have even considered biting the bullet and buying a sustainiac or fernandes system, if for nothing else to dissect the thing and make it all public (at least this should be simple enough for the driver portion) once and for all. You have consistently pointed to my driver being the issue over and over and I am convinced it is the biggest part of my problem. Hopefully, it'll get sorted.

So, until I can build another driver... You guys are brilliant. Keep it up. I am still hopeful.

Why would the longer poles cause EMI ? I don't get it.

Here I go again being intuitive. Let's call this extra length of magnet that hangs down "extra" for the moment. This extra length, is it being used? Is it not sending more magnetic flux laterally outward than shorter magnets of equal strength? You have gotten handy with some software that models fields, correct? Is this something you could model easily enough? Regardless, it sounds as though I am completely off base, but do you see where I am coming from at least?

I don't know why you would want equal sized permanent magnet above and below the coil ?

I mis-worded that. I want to not have the field so lopsided as it seems it would be in the configuration I have. Instead of equal magnet, I should have said equal field, as I would not expect that having much if any actual magnetic material above the coil is of use as it will put too much constant pul on the strings and at some point hinder any vibration.

The field is not destroyed and rebuilt, it is reduced and enlarged.

Isn't the entire field a sum of two components, a permanent field plus a temporary field's shift in one direction or another? So, whereas the overall summed effect is that the permanent field is weakened or made stronger, isn't this due to the continual destruction/reconstruction of the temporary portion in opposite polarities?

More significant possibly is the fact that the string is physically closer for one half of the wave than the other. The pull of the magnet is reduced with the square of the distance, so will be a lot stronger when the string is near the driver compared with when it is far. Another related effect is that any flux that gets passed to the pickup via the strings will be much more evident while the strings are closer to the driver. (this may be why the fizz is so nasal - more is getting through on that 'close' half of the waveform?)

I have wondered in the past if it might be worth contriving some circuitry that increases the power when the string is further from the driver and reduces it when it is closer - an asymetrical drive signal - using some sort of 'squaring' circuit. This might let us take the driver closer to the pickup as it would reduce the problem of the strings as flux conduit.

Are you certain that fizz is due to the the strings acting as flux conduit? Brings me back to my original question about the extra magnetic material... I guess I feel fizz could be coming from the permanent magnets hanging down and emanating flux laterally. I never got fizz in the tests that I did holding the driver above the strings, upside-down. It only began occuring once the driver was actually installed to the pickguard. I then thought that some of it was due to shielding on the pickguard itself as Sustainiac removes the pickguard shielding, but then I installed the driver on my guinea pig strat, which is not shielded except for a tiny section, and the fizz is still as evident.

Hmm, I guess that takes us back to an old question - why not only pull?... this is like the converse of that - why not only fight the permanent magnet.

More of the intuitive. I have tried only pulling, figuring the temporary portion of the field would react quicker and it would be a power savings as well. However, testing I did was completely unsuccessful. If I had to guess why, I'd say the coil could be likened to a speaker, in that it can not reproduce detail perfectly and so rounds any sharp changes, much like a speaker rounds the corners of a perfect square wave.

back to your drivers - why don't you try using one of the cheaper pickups with a bar magnet and steel poles ? you might find it works better or at least as well.

I have no reason other than I guess I've grown discouraged and have been waiting for some materials to try something drastically different, but now that you've suggested it, I may. Thanks for the discussion.

Just roughly thinking about this for 40 seconds.

How about a slide volume pot, like in a mixing board.

Maybe a 2 large metal balls on a track could push the slider side to side based on gravity?

guess I would need to spend a little more time thinking about this.

To take this a tad further, slider pot, wiper modified to have a ball rolling across it, so the the ball, presumably on a bearing and attached electrically, IS the wiper. Some company must be doing some form of this "motion pot" or "tilt pot" idea already... oh wait, yep they are! http://www.frederickscom.com/sens_tilt_0717_4315.html. That would be smooth.

No data, but something tells me that the extra pole magnet that sticks out from the used up 3mmm of the bobbing adversely effects the sustainer... any ideas?

I didn't understand that, can you try and explain again ?

I've been using SC strat bobbins. Not the cheapo type with metal poles and a bar magnet (though I have a few of those as well), but rather 100% magnetic pole pieces. My construction has been: unwind stock PU, bock up all but upper 3mm, wind coil in upper 3mm. This leaves the lower remainder of bobbin empty except for the lower portions of the pole pieces (total height minus the 3mm coil). I've not measured it, but I'd guess it's around 7mm to 10mm. What is the effect of having these poles left in their entirety as opposed to having polepieces only within the 3mm bounds of the coil? I know this is a theoretical best guess type of question at this point, but intuitively, I would think there is some waste with the extra length or an increase in fizz or some other EMI-related philoso-babble. I add this as question number 379 under "sustainer questions that shall never be (other than empirically) answered".

Intuitively, I would think the system would like it better to have an equally-sized permanant magnetic field both aboe and below the coil. I would also think that as is, there would be more phase lag or shift on one half of the AC wave form than the other as there must be some sort of effect on destroying and rebuilding the field in the opposite polarity.

Just checking in. I've stopped work on this project as I need a GOOD driver and I don't think my attempts have been there as of yet. I've used up my stock of spare pickups. No data, but something tells me that the extra pole magnet that sticks out from the used up 3mmm of the bobbing adversely effects the sustainer... any ideas? I have read here numerous times about not attempting to cut down neodymium mags, but what about ceramics? Can one safely file thsese down? I feel I need to make a bobbin from scratch, which IMO is a larger undertaking. I want to try and take advantage of multiple designs by making a dual coil thin design. I have my pals at work keeping their eyes out for scrap material for me to play with and until then, it's playing with circuits for now. Recently built and installed a 9v LED clipper fuzz on my guinea pig strat... not a permanent mod, more of an exercise in learning how to work with op amps more efficiently.

Anyway, some cool posts as of late. Can't wait to see what comes of the things being discussed recently... Col's current mode 386 and hank's hex work. Keep it up gents... and pete, should you need an extra few bucks, would love to purchase a coil from you.

I vote no mercury switches, the weight idea sounds intuitively best at creating a smooth effect. I'd find a way to use lead weight in a ball and socket joint for smooth operation if the axis of movement is not precisely aligned. Make it pendulum-like and the added length of the pendulum will provide leverage to magnify the power of the weight as well.

That is awesome. Great job!!!

Regarding the ticking, here are a couple of ideas...

Look into "mu" metals for shielding. This is EMI shielding, but may be quite expensive to cover the area in question.

Is the circuit entirely independent of the guitar circuit or are you sharing a ground? If yes, look into optocouplers to create a pseudo ground.

Kudos. The layout looks really nice right now.