psw Posted June 20, 2004 Author Report Share Posted June 20, 2004 That's the spirit LK, I do like a blue light. I noticed though that all of our city skyscrapers are crowned in blue light so maybe it will date. Bio - If this thing was separate from the guitar - kind of stick on - it removes the problem of specialized installation and modification of the instrument. Also, there is a question of product identification - If it is too hidden no one will know it's there nor want to pay for it... Sorry, the marketing side of me coming out there, got to focus more... Got a really spiffy look this new driver I'm working on - the CP7x - slightly narrower and curved in brushed aluminium... Oops... The circuit could be buffer ---> 6 band EQ split to ---> six amps with variable gain (trim pots) ---> driver elements. A global volume/sensitivity control would be required. The new version I'm about to trial is about 8 ohms (per string) I could do 4 ohms and run them in pairs with a broader 3 band eq and three amps Controls need to be on/off switch (and indicator) and sensitivity control. I was thinking of perhaps another control to switch in preset effects such as tremolo, auto wha, distortion and octave stuff that could also be set by trim pots on the circuit. anyway, lets see how the CP7x goes and a build up a hex version and test some eq ideas. I'll post the frequencies soon. Also, if there is some energy saving amplifier idea it may prove useful - it doesn't have to sound good to our ear afterall, just good for the driver check you later psw Link to comment Share on other sites More sharing options...
Biohazard Posted June 20, 2004 Report Share Posted June 20, 2004 Psw, yeah thats what I was trying to say (although knowing my luck I probably didn't phrase it right). If your idea could be mounted externally then it will appear to a wider audience. But if you also have the option of it being able to be in built then that means the sustainer will appeal to everyone who wants a sustainer because they can either mount it inside if they like (i'd choose this option) or externally if they don't want to route out their guitar. Link to comment Share on other sites More sharing options...
lovekraft Posted June 20, 2004 Report Share Posted June 20, 2004 ...I do like a blue light. I noticed though that all of our city skyscrapers are crowned in blue light so maybe it will date. That's because they're visible at the greatest distance at night - don't think that's gonna change unless our eyes evolve considerably. The circuit could be buffer ---> 6 band EQ split to ---> six amps with variable gain (trim pots) ---> driver elements. A global volume/sensitivity control would be required. Again, I think you're going to need some gain control, like a mini-compressor, to get the most out of your circuit and decrease power consumption in the driver circuit. It's fairly simple to implement, since we don't have to worry about fidelity, and it should cut current consumption in the power amp substantially, since the amp will only work at full power until it overcomes inertia and establishes a frequency lock, and then run at a lower level to simply sustain the vibrations. It would also immediately adjust, in case of partial muting by clumsy fingering, etc. Sensitivity could be a set-and-forget control on each "channel", at least with onboard installations. No global control needed, and string balancing is simplified. I like the idea of making it portable, but it's going to be fussy to adjust, and it'll probably need "recalibrating" every time you remove or reinstall it unless you figure out some kind of permanent solid mount for it. The new version I'm about to trial is about 8 ohms (per string) I could do 4 ohms and run them in pairs with a broader 3 band eq and three amps The only way you're going to get consistent results on 6-string chords is to use 6 drivers - even with only two strings per amp, eventually one string is going to win out. That may not matter to most people, but it means that I can't play 6 part chorales or string ensemble parts, so I might as well use my Fernandes. As always, just my opinion, worth every penny I got paid for it.. Link to comment Share on other sites More sharing options...
psw Posted June 20, 2004 Author Report Share Posted June 20, 2004 Well yes, 3 amps is a comprimise so 6 it is! It does mean a fair few wires from the individual driving elements Compression is definitely the go but needs to be adjustable. You need to be able to select the amount of driving force don't you think? I envision this as being more than an effect. With the CP1 experiments, tapping notes at different strengths caused a beautiful swell effect as the tiny signal built upon itself - I wouldn't want to lose potential by calming it down too much. I'm having a little trouble constructing the 8 ohm version (keep breaking them and wasting parts) but it would be interesting to see how this goes. Ill try and dig out a compressor and see how it goes... Heres an open question : How do you convert Henries H to uH and Farads F to uF - i.e. what is the multiplier for the "u" keep thinking filters cheers psw Bio - what would you want - inbuilt or add on? Link to comment Share on other sites More sharing options...
lovekraft Posted June 20, 2004 Report Share Posted June 20, 2004 It does mean a fair few wires from the individual driving elements Use a common ground bus, and you'll have 7 leads. Of course, you could always use ribbon cable with one twisted pair per driver, but since S/N isn't an issue at that point, I don't see any benefit.. maybe somebody else has some input on that. DIN plugs, edge connectors or DB-25 plugs might make good connectors - I could use some help there, since I know nothing about those connectors. Separating the driver assembly from the main board should simplify things, especially if you're making a removable system. Compression is definitely the go but needs to be adjustable. You need to be able to select the amount of driving force don't you think? I envision this as being more than an effect. With the CP1 experiments, tapping notes at different strengths caused a beautiful swell effect as the tiny signal built upon itself - I wouldn't want to lose potential by calming it down too much.Compression will actually help in that scenario - if it swells too fast to suit you, you can always adjust the output gain. It's as simple as using the amp's output to control a variable resistor shunted to ground on the preamp's input. That could be as simple as a JFET or LED/LDR opto, or since we'e not worried about distortion, a single CD4049 could be wired up to control all 6 channels. Add a single window comparator, and we can get it to open up at a certain signal level to shunt noise below a preset threshold. (Save that blue bit for your patent application - it's not anything new. but it might qualify as a novel application of existing technology.) I'm having a little trouble constructing the 8 ohm version (keep breaking them and wasting parts) but it would be interesting to see how this goes. Would it be easier to make the driver with a different impedance? Anything between 4 and 300 ohms should be easy enough to drive - we may have to use a discrete transistor in place of the LM386, but that might actually simplify the design. Make the simplest, most effective and cheapest driver possible (in that order), and then we can "tailor" a circuit to drive it. Heres an open question : How do you convert Henries H to uH and Farads F to uF - i.e. what is the multiplier for the "u" µ = *10^-6, so 1 µF = .000001 F. keep thinking filters Got filters for days, got a million of 'em - not a problem! Need info on the existing sytem to figure out where and how to insert a bandpass filter. A response curve on the driver would be extremely helpful, since it is going to have as large an effect on the channel response as the input filter, but I know that's not going to be simple to work up - we can probably get by without it, but the lowpass response inherent in any inductor is definitely going to play a major role in the frequency response of the system. Keep doing what you do, and see if you can find a link to the schematics you're using so I can start working on twisting them to our evil purposes!! <maniacal laughter>MWAAHahahahahah!!!</maniacal laughter> Link to comment Share on other sites More sharing options...
Biohazard Posted June 20, 2004 Report Share Posted June 20, 2004 Ok psw, since i'm having a custom guitar built, I'm building in a fuzz circuit to it and I would probably build in a sustainer too. However that is just me. There are other people out there who will also be like me and just want it built in. However, some other people might like the idea of a sustainer but not want to build it in. If you can appeal to both these kinds of people, then theres no reason for them not to buy your sustainer. Do you get what I mean? Link to comment Share on other sites More sharing options...
psw Posted June 21, 2004 Author Report Share Posted June 21, 2004 That sounds great LK, I know what you mean but finding, designing and building and testing such stuff for me would take alot of time and $ and remove what little of my hair that remains!! So I'll try out some stuff and perhaps we can arrange for me to send you something to help with this project and in return for your input...(unless of course you're really Larry...) I think were thinking along the same lines. Simple is best. I'm not sure about the fidelity question. It may prove that signal quality is important so as not to contaminate the signal with too many stray, unrelated frequencies that might crossover into the guitars pickup field...on the otherhand perhaps a square wave is the go... The 386 was just a convieniant device to test drive these ideas, so I'm not at all committed to this This wouldn't normally be a problem except that I've been concentrating on reducing magnetic radiation from the driver design but they're unlikely to be perfect...afterall if nothing got out it couldn't move the string!...and these things are running very close (10mm) to the pickup. Will be going to the country in the next week so I'll be pondering our progress down by the Ocean Road...(a stunning place by the way LK, nothing like this down your neck of the woods)...but I hope to complete some tests on the CP7x befor I go. Stay cool psw P.S. Protecting my driver is becoming an issue, a patent in OZ only protects you down here but as soon as you disclose it the rest of the world jumps on it and patents it everywhere else . A worldwide patent costs big bucks...does anyone have ideas on how to get some protection (and credit and possibly $) but still be able to get this thing out to people such as yourselves who can put it to good use...don't mean to sound paranoid, but... Link to comment Share on other sites More sharing options...
lovekraft Posted June 21, 2004 Report Share Posted June 21, 2004 ...(unless of course you're really Larry...) Nope, old and fat, but definitely not Larry (or Randall, or Seymour, or Bill Gates, either). I'll try to work up a proto circuit and do some testing, and if I can get it to work well, I'll figure out some way to get it to you for testing. I can use a tiny 8 ohm speaker to simulate the driver - give me a week or so to figure out how I can make it work. I could sure use a look at the schematics for your working system (hint, hint...). I'm not sure about the fidelity question. It may prove that signal quality is important so as not to contaminate the signal with too many stray, unrelated frequencies that might crossover into the guitars pickup field...Keep in mind that the inductance of your driver is going to act as a lowpass filter above its resonant frequency, so harmonic distortion and noise are going to be reduced above that point (yet another hidden "feature"). You can smooth a pulse wave into a near sine wave with the right inductor. Will be going to the country in the next week so I'll be pondering our progress down by the Ocean Road...(a stunning place by the way LK, nothing like this down your neck of the woods)...Yes, you live in one of the most beautiful places on earth - thanks for rubbing it in. Current temperature 93º - Humidity 87%, wind calm - outlook for today, partly cloudy, continued hot, with a chance of strong thunderstorms by late afternoon. Outlook for tomorrow - the same P.S. Protecting my driver is becoming an issue, a patent in OZ only protects you down here but as soon as you disclose it the rest of the world jumps on it and patents it everywhere else . A worldwide patent costs big bucks...does anyone have ideas on how to get some protection (and credit and possibly $) but still be able to get this thing out to people such as yourselves who can put it to good use...don't mean to sound paranoid, but... I'd go for patents in Australia and the US - you should be able to get a US patent by using an agent in the States. Shouldn't be very expensive, I'll look into it. Or you could write Larry a letter and see if he wants to pay you several hundred thousand dollars for it!! Link to comment Share on other sites More sharing options...
psw Posted June 22, 2004 Author Report Share Posted June 22, 2004 Larry seems like the kind of guy who'd change the color and call it his own..I was shocked to see what he has patents for!!!!!!!!! I'll see what I can do about the schematics see how the new driver goes and if it checks out ok send you a single to test and critique ... I think it's time that someone other than me takes an actual look at the thing. check you later psw Link to comment Share on other sites More sharing options...
psw Posted June 22, 2004 Author Report Share Posted June 22, 2004 UPDATE The CP7x in an improvement, after a few false starts. I am getting a grainy type of distortion which could be caused by the string being driven too hard or too much gain in the preamp stages causing it to be driven by a fuzz box!. It was particularly effective with the bridge and middle pickup selected. I'm not getting the beautiful swell effect from lightly tapped notes that I got from the CP1 tests as it responds immediately. The CP7x, like others I have been making, are single string drivers. That is, they are one of six elements that will be required. The CP7x measures 100mmLx5mmWx8mmH and it's unique design is the key to its success. I have anticipated some of the problems of combining these elements and have a plan to eliminate crosstalk between the drivers. They may even work better together if my theory is correct...well have to see I still haven't abandoned the idea of tuning the resonant frequencies of the drivers to the strings and driving them from a single simple amp (probably with some compression). This way it is the passive design that creates the efficiency, not some electronic compensation. Power consumption will also become an issue. The current set up is using a regulated wall wart supply of 7.5 volts. more important than the voltage though is the current I suspect and such a power supply has currrent in spades. So, testing will continue on this (by the way LK this one is 8 ohms) there are quite a few potential variables in the design before I even get close to the electronics side of things...or perhaps I'm just more in my comfort zone with magnetics... So thats where I'm at to date see ya, mates! psw Link to comment Share on other sites More sharing options...
GregP Posted June 23, 2004 Report Share Posted June 23, 2004 I know nothing about electronics, but a HUGE feature would be the ability to select responsiveness. You could dial in either those nice swells for orchestral effects, or instant-on sustain for seamless sustaining of notes. Link to comment Share on other sites More sharing options...
psw Posted June 23, 2004 Author Report Share Posted June 23, 2004 You got it!!!!!!!!!!!!GregP Further tests on the CP7x show that by manipulating the gain you can get a fundumental response to an octave and various harmonics above all from a single rotary control Other tests have been very satisfying without any fancy amp-sy (you might want to hold back LK!). This thing is starting to sound really beautiful...I think I'm in love...looks good too! I need to set up some filters to remove some high frequency oscillation, and the signal is distorted by multiple notes being used to drive single strings...may only really be sorted by some clever hex PU system or an eq that won't mind these harmonic jumps. You can even get notes to sound as harmonics simply by adjusting this control...the use of a preamp rather than just a simple buffer maybe a happy accident. I think we are creating something that goes well beyond sustain...will someone tell me what I should do with it!!!!!! cheers psw Link to comment Share on other sites More sharing options...
Biohazard Posted June 23, 2004 Report Share Posted June 23, 2004 That would be another amazing feature as well as setting the sensetivity of the device, if you can add an option to make the notes sounds like harmonics then that would be ace too. Thats one thing that sounds cool on the Fernandes sustainer system, the harmonic feedbac mode as well as standard sustain mode. I think your really getting something here. Amazing work. Link to comment Share on other sites More sharing options...
Andreas Posted June 23, 2004 Report Share Posted June 23, 2004 Im missing out for a few days and you go and finish the sustainer. so selfish I see you made some serious progress in this. I haven`t read all of it yet and I dont have time now. Im back to organic, inorganic chemistry...chemical kinetics mass spectroscopy , nuclear magnetic resonance (has absolutelly nothing to do with either magnets or sound resonance) and a lot of other crap I have to shovel down my brain for tomorrow. Keep up the good work, I cant wait to read in detail the progress that it is made. Cheers, Andreas. Link to comment Share on other sites More sharing options...
psw Posted June 23, 2004 Author Report Share Posted June 23, 2004 Thanks guys. And Andreas, concentrate on those exams, you never know what information will be of use, I bet there's even more I could do on this if I were able to understand the theory and do the sums or even have a more disciplined mind... good luck psw Link to comment Share on other sites More sharing options...
psw Posted June 24, 2004 Author Report Share Posted June 24, 2004 Continuing to get good results...but have a few faults still Am having electromagnetic radiation problems that occur only when a string is not being played...A constant tone is heard which chirps when grounded by my hand on the string] Besides that it's working perfectly...well, very well... I can reconfigure the polarity cycle of the fixed magnets and see what effect that has... I have tried a few things short of that...I can effect it but not fix it I've even thinking of going back to the CP6x configuration...less powerfull but I suspect a better contained field...hmmm...maybe the original ideas are the best! I'm having trouble recognising on from another...now is this cp6x or cp6.1x... LK and Ansil have been sent PM to see if they can come up with anything (hint) It will work with no noise at all when the neck pickup is selected...you also get a different drive sound...not as loud, more fundamental fading into an octave above over time or sooner with a little vibrato...nice The ability to use different pickup combos is a major plus with this system which makes it unique. Perhaps I do need to build the thing in and rewire the selector so that the opposite pickup is selected to the active signal pickup...if you get my drift That is...Neck PUp--->amp // Bridge PUp ---> drive and visa versa The inbetween settings are a little odd sounding so could be ommited from the drive chain but kept in the signal chain I'm not sure if this will be a fix and I'm a little lazy to dismantle the strat to test it out...unless someone thinks that this really could be the answer. I've been able to get the driver to work just ahead of the bridge saddle, making a bridge driver option possible. I'm not sure that people want that...it would be neat but too many bridges to convert and I'm not sure how a floyd would go. One last thing...could you guys check your guitars and give me an idea how much space is clear of the bridge and the bridge Pickup and how much height...I found on my strat copy that 8mm is a little too much...I could tilt the neck back, etc but I'd rather make something that fits than to %$^ with my setup! night, night psw Link to comment Share on other sites More sharing options...
ansil Posted June 24, 2004 Report Share Posted June 24, 2004 "Am having electromagnetic radiation problems that occur only when a string is not being played...A constant tone is heard which chirps when grounded by my hand on the string]"" what about some sort of gate on it. say something that involved charging a capacitor maybe wit enough juice to activate a transistor as an on switch. just an idea. something like the tracking feature in the joedavissons shoctave harmonizer. Link to comment Share on other sites More sharing options...
psw Posted June 24, 2004 Author Report Share Posted June 24, 2004 I was burried in spam and just got some behind the scenes email from LK and Ansil...sorry about that guys Ansil - I had thought of a gate and it would probably conserve power too but would rather not as it would stop the effect of swelling from "nothing" that should be achievable as well as responding to picked notes LK has suggested it maybe oscillation from the power running too close to components. As my little plastic jiffy box has undergone a number of mods There could be all kinds of problems (ground loops, etc) in there so I'll have to check this out. If thats the problem it would be great I still like the more neutral passive magnetic cycle of the CP6x. One reason for abandoning it was that it seemed to be driving the string at the octave harmonic immediately. Now with the new amp driver I'm wondering if it just wasn't too efficient. The CP7x will create a similar effect when driven hard...hmmm With all of the x series designs the string is driven in a more natural motion (not up and down) so it's hard to tell by eye or touch whether the motion is the normal string vibration or a product of the driving force...not very scientific but there you go Much appreciate the input...keep it coming psw P.S. I was getting really frustrated and going to give it a rest but you've given me hope to carry on...It's taking a little more time and mental energy than is healthy... Link to comment Share on other sites More sharing options...
ansil Posted June 24, 2004 Report Share Posted June 24, 2004 hmmm that may be true about the supply voltage. didnt' think about that. what kind of cap are you using across the rails. ??? or what size rather. if you have a 500uf try that. Link to comment Share on other sites More sharing options...
southpaw rocker Posted June 25, 2004 Report Share Posted June 25, 2004 I'm too lazy to read all twelve pages of this thread so I don't know if this has come up. is it possible (in the fernandes model sustainer system) to change the just pickups or are they special pickups made just for the sustainer system? Link to comment Share on other sites More sharing options...
psw Posted June 25, 2004 Author Report Share Posted June 25, 2004 Ansil - I've got 100 between + & - (if thats what you mean) both on the preamp and amp...I'll try out some larger ones. Would using a battery fix it do you think? Southpaw - This has been a saga and most of the pages can be ignored. Basically, I'm working on a sustainer system similar in principle to the Fernandes, etc. These are basically a pickup in reverse. This "driver" receives an amplified signal from the guitar causing an endless feedback loop. The guitars pickups are stock and the driver replaces the neck pickup. This is so electromagnetic radiation doesn't interfere with the bridge pickup. Only the bridge pickup can be used while the sustainer is on...if you get my drift. To get you up to speed...I have developed several tiny drivers that should be able to slip under the strings near the bridge. The small size and unusual design is aimed at reducing radiation so that the guitar works as normal and no permanent alteration is required. It looks like it will be a hell of alot cheaper too! But there are bugs...I have it working with the all pickups but this EMI appears to be present in the nearest pickup as it is not apparent when the neck pickup is being used. Interestingly though, while a string is being played and sustained this continuous tone disappears...hmmm Well, nothing comes easy...it was going so well there for a while. If there's not some way to quiet it down electronicly, I'll have to deal with it by magnetic design. I've come up with an idea for a CP8x but initial tests still have EMI problems Hope this answers your question in a round about way psw Link to comment Share on other sites More sharing options...
southpaw rocker Posted June 25, 2004 Report Share Posted June 25, 2004 yeah, thanks. both sustainers on the market i've seen are magnetic but i don't think i'm smart enough to contribute so don't mind me Link to comment Share on other sites More sharing options...
lovekraft Posted June 25, 2004 Report Share Posted June 25, 2004 Ansil - I've got 100 between + & - (if thats what you mean) both on the preamp and amp...I'll try out some larger ones. Would using a battery fix it do you think? I think the placement of those bypass caps is as important as their value - I was taught to connect them directly to the IC power pins to avoid oscillation even when using a battery supply. That was a long time ago, but it should still apply. This may be the magic formula for the LM386: To avoid oscillation of the circuit, it is a must to connect a 100uF electrolytic capacitor between pin #6 and ground. This capacitor is shunted in parallel with another one of 0.1uF. It can be either ceramic or mylar. I have it working with the all pickups but this EMI appears to be present in the nearest pickup as it is not apparent when the neck pickup is being used. Interestingly though, while a string is being played and sustained this continuous tone disappears...hmmmIt may well be that the pickup signal is swamping out the oscillation. If there's not some way to quiet it down electronicly, I'll have to deal with it by magnetic design. Try a piece of iron or mild steel between the drivers and the pickup - it might provide enough magnetic shielding to eliminate the problem. It's an old trick that amp builders use when they have to put transformers too close to sensitive components due to space constraints. Link to comment Share on other sites More sharing options...
psw Posted June 25, 2004 Author Report Share Posted June 25, 2004 LK - the circuit I'm using has a 100 uf cap on pin 6, I'll try the parallel cap but a little skeptical as it works from the neck pickup idicating that, if far enough away from an active pickup it does work. I suspect the "tone" is the resonant frequency of the driver. Have tried various devious shielding means to little effect a 470uf across the +/- changes the pitch but not lose it. Could it be a ground loop - I've got the preamp wired to the amp both in power and signal, both with a 100uf to ground - ?? Seems like the theory that between the string the pickup and the driver the resonant frequency of the dominant element wins out - in this case the string - If left to squeel the string vibrates an harmonic octave above and takes over. Getting disheartened here check you later psw P.S. Southpaw - Don't worry about the technical stuff, I'd like to know what you would like a sustainer to look and sound like... Link to comment Share on other sites More sharing options...
psw Posted June 27, 2004 Author Report Share Posted June 27, 2004 Just thought I'd post an update... In an effort to reduce the height of the driver and to address these EMI issues a little I've come up with yhr CP8y This driver element uses similar technology to the x series driver elements. It seems to require more power to run but then outputs less EMI. Part of the reason may lie in it's smaller size (about 5mm high). I don't think i'm goning to be able to make them much smaller! For the first time, I also set two up as a two string driver to explore the elements use in this way. I discovered some really interesting phenomena in the course of testing that may help the x series drivers should I decide to go back to them for their power efficiency. I can think of a couple of variations of this new driver based on my experience with the x series so that will give me something to work on. So...the state of play down here...As of last night I was able to run any two strings (two string driver) from about the centre PUp position on a cheapo single coil strat with a driver small enough to be attached to the scratchplate with no EMI using the neck or bridge pickups. Therefore I have in theory matched current technology in driver design and surpassed it in being able to use diferent PUps and combinations and being small enough to install without any modifications to the instrument. Sometimes I need to remind myself of how far I've come with a project! I think that it's time to tidy up the driving amp question. Like the driver, it may require a novel approach. Simple is best and I don't really want to use gates, etc to tame the thing down. I need a buffer to isolate the guitar signal and not load it down... I need an power efficient amplifier as I think that battery drain may be excesive... I need some control over the effect and switching that is user friendly... I had been thinking that if the amp and controls - like the drivers - could be miniaturized they could be built into a single enclosure requiring only the addition of a battery or a secondary surface mount control unit...any ideas? I need to do more testing and less thinking I fear...will be away from the soldering iron and the computer for a while...going up the country and down to the coast...that should give the old brain a rest and perhaps I'll return from a different angle see ya, mates psw Link to comment Share on other sites More sharing options...
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