www.5zhi.com Posted September 25, 2006 Report Share Posted September 25, 2006 Who may provide the PCB and SCH document?Thanks Link to comment Share on other sites More sharing options...
col Posted September 25, 2006 Report Share Posted September 25, 2006 Who may provide the PCB and SCH document?Thanks just like in the grolsch ads "it's not ready yet" afaik, this circuit only exists on my bread board. It is currently in a state of development. The schem posted here is already out of date, and it would be crazy of anyone to create PCBs for a circuit at this stage of development. If you want to try it out, the best thing to do is by a plugboard/breadboard, the components, and plug them all together. Then as the development continues, you can chance parts at required. As soon as the circuit is in a more finalised state, I will design and post a perfboard layout. If you're lucky someone else at that point might make a pcb - who knows. when you say SCH document, do you mean for ExpressPCB ? cheers Col Link to comment Share on other sites More sharing options...
psw Posted September 25, 2006 Author Report Share Posted September 25, 2006 welcome www.5zhi.com to the sustainer thread... It is currently in a state of development As is this whole project... ...regardless of the circuit you use, the driver and how it is implemented will still be at the heart of the thing. If you would like to attempt this thing now, my guitar works perfectly well in it's own way and others have successfully made sustainers along the same lines. You could make the thing and drive it with something like the fetzer/ruby circuit, then swap out this later for something like col's when it has been more developed. The same could be done with the drivers as other ideas and theories, or ideas of your own come up... Sorry about that...we are looking still at creating some kind of "standard" circuit to make things a little more approachable...but this too is "in the works"... pete Link to comment Share on other sites More sharing options...
psw Posted September 26, 2006 Author Report Share Posted September 26, 2006 I was wondering today... Why is it that my guitar works with a high gain preamp and the LM386 at x200 gain with a basic single coil thin driver? The only difference that I can see from my circuit to the fetzer / ruby or something like col's proposal is filtering of signals outside of the audio range. Perhaps that is it. I just have to wonder though about the amount of problems people are having or anticipating with EMI with the "thin driver" idea, which itself is designed to limit EMI... Just a thought...it definitely does not work as a mid driver, it can't go that close to the bridge pickup...but it does function perfectly happily in the neck position on the strat... pete I am also thinking more about a modular system. Placing the power amp section close to the driver would have the advantage of limiting the amount of EMI producing, and efficiency robbing, driver wires within the guitar. The harmonic effect could be created by inverting the signal between the preamp and the poweramp in some way (a guitar's harmonic switch, or inverting the magnet will produce the identical effect as reversing the driver leads) keeping the driver leads out of the guitar's control cavity. Now...what kind of preamp would we need to achieve this...a TL072 perhaps with a buffer and adjustable gain for the sustainer. Anyone want to suggest such a circuit? I might try to do a layout for the poweramp section with that layout program...just for fun, to see how small this could be... take care... p When I get a moment I will do a drawing of the "split blade" rail driver I mentioned for further comment...I think it may have some merit and is worthy of consideration. I also have an idea for a bobbinless driver jig that may be easier to build and use for it's construction. I wonder how "thin" a driver could go and still be effective, and what the size would be of various thicknesses of coils for a twin coil driver. Perhaps it could be made even thinner!!! Link to comment Share on other sites More sharing options...
col Posted September 26, 2006 Report Share Posted September 26, 2006 I was wondering today... Why is it that my guitar works with a high gain preamp and the LM386 at x200 gain with a basic single coil thin driver? The only difference that I can see from my circuit to the fetzer / ruby or something like col's proposal is filtering of signals outside of the audio range. Perhaps that is it. I just have to wonder though about the amount of problems people are having or anticipating with EMI with the "thin driver" idea, which itself is designed to limit EMI... Just a thought...it definitely does not work as a mid driver, it can't go that close to the bridge pickup...but it does function perfectly happily in the neck position on the strat... pete Could be a lucky combination of guitar hardware, strings, driver construction, pickup design, circuit... etc. However, you've noted that you get some fizz when you play in harmonic mode. So you're still getting the same issue as others.... maybe its slightly worse on my setup and/or onlastgoodbyes... baybe its a matter of perception - one persons 'barely noticable' can be anothers 'completely unacceptable'.... Q how well does your bridge/trem attract a magnet ? (I just checked mine on a hunch, and even with a pretty strong magnet there is very little attraction - so possibly I would have less of a problem if my trem used a more magnetic alloy that would sink some EMI) Also, there is the pickup - a strat pickup has somewhere between 6000 and 8000 turns... a paf humbucker has about 5000 per coil, a JB like mine has twice the resistance, so maybe as many as 8-10,000 turns per coil. My guess is that this would make it more susceptible to the parasitic transformer coupling between pickup and driver, or at least magnify the issue. At some point, I will get around to switching the JB for a weaker pickup (don't have any single coils though), to see if that makes a difference... it maybe that non-magnetic bridge/trem though... I am also thinking more about a modular system. Placing the power amp section close to the driver would have the advantage of limiting the amount of EMI producing, and efficiency robbing, driver wires within the guitar. The harmonic effect could be created by inverting the signal between the preamp and the poweramp in some way (a guitar's harmonic switch, or inverting the magnet will produce the identical effect as reversing the driver leads) keeping the driver leads out of the guitar's control cavity. I've been thinking about this as well. There are potential goods and bads... Breaking the circuit into seperate components will make it easier to squeeze it in to a guitar that doesn't have much space. The circuit can be designed so folks can start with just the pre-amp and power-amp, then add an AGC at a later time. If phantom power is used along with surface mount tech housed in the same unit as the driver, its possible that we could have just a slimline driver with a cable - very few mods within the guitar (maybe even none). It may be that putting the poweramp circuitry within 'X'mm of the driver can cause EMI related problems directly between the driver and the LM386, or its support circuit. The construction becomes more difficult - building, mounting and connecting a single board, and driver (assuming you can find space for the board) is easier and less error prone than having multiple circuits with all the required connections, mounts, ground points, and possibly the need for these to be shielded... News on my circuit. I Am in the middle of some updates, that if successful will be a good step forward: variable width of the 'Dynamic Range Inverter' curve. variable peak position. Also, a simpler circuit with fewer components. (it might use less power as well - not a lot though). Right now the knob for the inverters curve interacts with the output level (a lot), this means that any change in the curve requires a change in the level knob - making setting the thing up quite tricky (a bit like when the tone knob on a stomp box also changes the volume level - its difficult to A/B two settings). So I'm trying to work something out with a dual ganged pot and some resistors... This will put the circuit complexity back to where it was... just can't win... hehe Anyway - 'IF' this works out, I'll most likely leave it at that for the time being and put the thing on some perf board. So - fingers crossed cheers Col Link to comment Share on other sites More sharing options...
psw Posted September 26, 2006 Author Report Share Posted September 26, 2006 (edited) Could be a lucky combination of guitar hardware, strings, driver construction, pickup design, circuit... etc. No...the bridge is diecast on this guitar so wouldn't have much influence...besides, I tried the same thing on a genuine LP and it worked ok.... Also, there is the pickup - a strat pickup has somewhere between 6000 and 8000 turns... a paf humbucker has about 5000 per coil, a JB like mine has twice the resistance, so maybe as many as 8-10,000 turns per coil. Well, yes...it could be the sensitivity of your pickup...mine is, as it happens, a stacked humbucker in the bridge. You could try splitting the humbucker to drive the thing, but I don't think this would help things. The mid pickup may have some influence. On the LP there was the otherside of the HB between the driver and the bridge pickup...hmmmm As for the fizz...I'll have to record it, it only happens on ultra-crystal clean settings in the harmonic mode. There is none at the same settings in the normal drive mode. I tried it without the digital effects into the amp and the "noise" is the same so it isn't that. It also is not a background noise as the guitar is silent except when a note is being played. It may be something to do with the way the harmonic is being produced (the suppression of the fundamental and trying to drive harmonics) as much as an EMI problem between pickups. It is worse when the battery runs low...I will do some further playing and listening to try to work out what it is...maybe even record it so you guys can try to work it out. It doesn't sound like any of the classic EMI sounds (eg therimin like shreeks!). Maybe it is somethin in my circuitry (filter caps) that are having trouble processing these high frequency harmonics, and that is causing some weird distortion...it is a low level background sound...more reseach required...hehehe Breaking the circuit into seperate components... If phantom power is used along with surface mount tech housed in the same unit as the driver, its possible that we could have just a slimline driver with a cable - very few mods within the guitar (maybe even none). Yes, I saw this possibility...but then there is the switching...I was looking into electronic switching with surface mounted switches mounted "on" the guitar...but this would be a long way off and only really a commercial proposition. I doubt the market would be big enough for such a venture...hehehe...but it's good to dream... It may be that putting the poweramp circuitry within 'X'mm of the driver can cause EMI related problems directly between the driver and the LM386, or its support circuit. I don't really see this as being too much of an issue...it is possible, but the advantages overcome them. especially if it were possible to mount the thing under the pickup or somewhere like that. My circuits are on two boards mounted back to back with the capacitors mounted on their sides to save space. I suspect it may be possible to get your design down to a similar size to mine anyway with careful planning. Anyway - 'IF' this works out, I'll most likely leave it at that for the time being and put the thing on some perf board. So - fingers crossed Good luck...I think there is a lot of promise in the concept of your circuit's intentions. I don't know enough about how to design circuits, but am not sure if this is the best or only way to achieve a similar result, and even further complexity could be an issue. I am thinking that some kind of circuit that simply varies the resistor between pins 1 and 8 in accordance with the incoming dynamics of the signal may be good...but I wouldn't like to kill the "bloom" effect of notes increasing in volume as they sustain completely, just a little more refinement... I still intend to mock up the poweramp section...is it possible to isolate just the buffer/preamp part of the circuit from your design? I still have some concerns about my preamps input impedance (though I don't seem to have a loading issue on this guitar) and I like the buffering idea of the guitar itself. Maybe this would address my "pop" issue that occurs on switch off... I was thinking that such a preamp would allow for the inversion of the signal in some simpler way before the poweramp, allowing the harmonic switch to only have to deal with low level signals and keep the driver wires away from the control area and other sensitive parts of the guitar (pickups, etc)... I will post some driver concepts soon for people to comment and brian storm... pete Anyways...good luck, I think the circuit should work even better off the breadboard Oh...and I was looking into some kind of surface mount to DIL adapters so as to perhaps broaden the DIY into SMD technology...on this thread, SMD adaptersthe guy made such adapters...perhaps we could exploit some of the new class D and all in one, low parts count SMD devices available for mobile phones and such with this kind of thing...or at least experiment with them.... Edited September 26, 2006 by psw Link to comment Share on other sites More sharing options...
col Posted September 26, 2006 Report Share Posted September 26, 2006 (edited) Oh...and I was looking into some kind of surface mount to DIL adapters so as to perhaps broaden the DIY into SMD technology...on this thread, SMD adaptersthe guy made such adapters...perhaps we could exploit some of the new class D and all in one, low parts count SMD devices available for mobile phones and such with this kind of thing...or at least experiment with them.... I think you just opened up a can of worms try googling "SMD adapter" - there are LOADS commercially available. e.g. here or here - some of these can be used with multiple footprints of chip, others can convert them to standard dip sizes... cool stuff I guess the trick would be to buy one or two to test the water, then buy some pcb diy kit and make a batch of home brew ones. Anyone wanting to build a circuit could go with a commercial adapter... edit: seems like farnell(and others) do a range of smd to sil adapters (like the ones you posted a link to). An 8 pin adapter is less than £2. Great for breadboarding, and also for helping the layout in the final perfboard build Col Edited September 26, 2006 by col Link to comment Share on other sites More sharing options...
ebenezer shred Posted September 27, 2006 Report Share Posted September 27, 2006 Hmm... Haven't been on this thread in a while, glad I did. I was wondering if there was some way (going back to psw's sustainer idea) I could just put a driver in the guitar, then have the board and everything in a pedal on the floor. Is this possible? (never mind if it's impractical to building it into the guitar) Link to comment Share on other sites More sharing options...
psw Posted September 27, 2006 Author Report Share Posted September 27, 2006 Ok...so now you got me checking out amp options again (I wish I had my soldering iron and stuff available, we'd make so much more progress if I could make stuff up and plug it into a known working guitar...oh well, it will come) Anyway...short of the class D route...do you know anything about the TBA820M mini 8 Dip chip (I found a link from that futurlec site to the data)...seems to be able to put out 1.6W into 4 ohm or 1.2W into 8 ohm, a max drain current of 12mA and an input resistance of 5Mohm. Could it be that such an input resistance need not require a preamp, particularly since it can supply more power if required? Also, it appears you can connect load (ie driver) to the supply voltage rather than ground. This could address some of the ground problems and switching complications associated with installing the thing perhaps. Otherwise, great links to those commercial adaptors, there are some fascinating chips out there...getting them and soldering onto the adapters may even be a little tricky, but these ones are a lot cheaper than some I have seen...I had been discouraged. The link I gave has a link to a file of the artwork to make your own, but I too don't like the idea of making my own boards. There are a lot of developments in amp and chip technology, if anyone is wondering what we are on about, that are directed towards devices such as mp3 players and mobile phones that are tiny, efficient and are powerful enough to drive this project. The problem is that they are just too small to work with! As a result, the DIY hobbiest is working with technology like the LM386 that is very old and require more extra components and power than more modern devices. They are also not really that readily available in small quantities, but this could be overcome if detirmined, and you had something that you were sure would do the trick. I intend at some point to return to some kind of pickup design research, which is what I was doing when I started this stuff. I have a pickup winder and a large roll of pickup wire for the purpose, suppiers of rare earth magnets and some exotic materials and construction techniques....and of course a lot of ideas! Some of those ideas may involve active electronics and so my interest in buffer's and preamplifiers not only for the sustainer project, but for future projects as well. At some point it is possible that the two sets of projects could converge and a set of active pickups, onboard electronics and incorportated sustainer technology could be devised. Once you break the avoidance of having a battery in the guitar (or remote power) you open the door to tone shaping, low impedance small coil pickups, combination piezo/mag sensors...all kinds of things. Also, much of the circuits can serve a dual purpose...a preamp that buffers the guitar's signal or runs a low impedance active pickup (a la EMG) could also serve to condition the sustainer signal with very few extra components...loading would not be the issue it is with passive pickups. These types of things are common in bass guitar technology...yet the guitar has remained fairly dormant (EMG's aside) in this regard...a little strange...but there you are! I guess...without going overboard...that if such a convergence were successful, over time the sustainer technology could become common place and influencial in the development of guitar music. If I could afford it for instance, the line 6 modelling guitar is perhaps one of the more ideal platforms for this device. Not only can you get all manner of instruments and pickup sounds, not only does it already have a remote power option...but it does not have any magnetic pickups...it is piezo, so there should not be any EMI interaction between the driver! Speaking of which...I wonder what happened to Myka's piezo/sustainer guitar project he was looking at doing? On with the research...we don't seem to be having too much help from the "guru's" on circuitry...may be time to look a little further a field...what is the input impedance of a guitar's pickups anyway, what are we aiming for to avoid loading? pete Link to comment Share on other sites More sharing options...
psw Posted September 27, 2006 Author Report Share Posted September 27, 2006 Still at it E. shred!!! Hmm... Haven't been on this thread in a while, glad I did. I was wondering if there was some way (going back to psw's sustainer idea) I could just put a driver in the guitar, then have the board and everything in a pedal on the floor. Is this possible? (never mind if it's impractical to building it into the guitar) We have discussed this option in various ways...there are some major problems...you may need to run two leads to the guitar...one for the driver and the other for the signal to the amp. Mixing them could cause a lot of problems with EMI from the cables themselves. You would also likely need more power, but this would be less of an issue as it wouldn't need to run off batteries! I looked at various ways that everything could be mounted in a surface mounted box (like a tailpiece) with a very small surface mounted driver. The problem is that you would still need (except for a single pickup guitar I suppose) major rewiring and bypass switching inside the guitar. The photo of my "sustain box" on the LP in the above post, and pictured off the guitar here... may appear to be just what you are talking about, but it isn't really! This is a testing device...there is no bypass switching and the driver is not permanently mounted to the guitar, nor the neck HB function properly as it is lowered so much to fit the driver on, and the other coil not compensated...that it does not function too well. It is a replica though of the driver and circuit that is in my guitar and a useful device none the less...but not really for playing. There are some sounds of the thing on the sounds thread, but it did not work as well as it does on a fully installed guitar like my strat. UPDATE: Playing my strat just now with ulta clean sounds to get the "fizz". This is not EMI. I think that this is amplification of high pitched fret buzz and loose components and such! In order to get the harmonics to ring loud and true, the amplifier needs to be set so as to reproduce such high sounds...consequently you need a lot of treble and headroom to get these kinds of sounds. You can do it quitely with some compression for instance but this brings out the background noises (like this "fizz"). It does not sound in fundamental mode on the same settings....I think...because the full bodied sound of the whole note (not just the higher artifacts) overwhelms these things and the strings vibration is more natural. More needs to be done to look into it more fully, but that is what appears to be going on. Bear in mind also, that I am talking a very sterile clean sound...nothing very attractive about it...almost painfully brittle and high fi and not something you would naormally choose to play music with in the real world. Only a slight bit of hair (would still be regarded as clean) is required to give body to these high harmonics and eradicate the "fizz" effect!!! So...it does appear to work ok...I wish to build another, better quality sustainer guitar in the future that will shed more light on things I guess... pete Link to comment Share on other sites More sharing options...
col Posted September 27, 2006 Report Share Posted September 27, 2006 Ok...so now you got me checking out amp options again (I wish I had my soldering iron and stuff available, we'd make so much more progress if I could make stuff up and plug it into a known working guitar...oh well, it will come) Anyway...short of the class D route...do you know anything about the TBA820M mini 8 Dip chip (I found a link from that futurlec site to the data)...seems to be able to put out 1.6W into 4 ohm or 1.2W into 8 ohm, a max drain current of 12mA and an input resistance of 5Mohm. Could it be that such an input resistance need not require a preamp, particularly since it can supply more power if required? Also, it appears you can connect load (ie driver) to the supply voltage rather than ground. This could address some of the ground problems and switching complications associated with installing the thing perhaps. Not sure, although I'm mot really so interested in the input impedence of the poweramp stage - I'm sticking with AGC just now. And The LM386 seems to work well, and its easy to get. I really want to try class D at some point, but for now the goal is to complete the AGC, install the system properly and try to debug the low level fuzz on clean sounds (or at least understand it better). Heres another reason for pro SMD - voltage! Many of the newer techs work on much lower voltages, so it may be possible to use 2 AA cells instead of a 9V battery - these could provide a similar or longer life, and are much cheaper to replace (most likely no good for an 'active' buffer though due to the limited head room). Otherwise, great links to those commercial adaptors, there are some fascinating chips out there...getting them and soldering onto the adapters may even be a little tricky, but these ones are a lot cheaper than some I have seen...I had been discouraged. The link I gave has a link to a file of the artwork to make your own, but I too don't like the idea of making my own boards. check these out. Its like an smd riser card - space for a chip, and the supporting components in smd form. we could probably do the whole circuit on a couple of these - with one ore two little trimpots and caps on the main board. That site also has a guite on how to use their tech - and its cheap stuff. There are a lot of developments in amp and chip technology, if anyone is wondering what we are on about, that are directed towards devices such as mp3 players and mobile phones that are tiny, efficient and are powerful enough to drive this project. The problem is that they are just too small to work with! As a result, the DIY hobbiest is working with technology like the LM386 that is very old and require more extra components and power than more modern devices. They are also not really that readily available in small quantities, but this could be overcome if detirmined, and you had something that you were sure would do the trick. Much of the class d tech needs more supporting components - filters etc. On with the research...we don't seem to be having too much help from the "guru's" on circuitry...may be time to look a little further a field...what is the input impedance of a guitar's pickups anyway, what are we aiming for to avoid loading? pete heh - my last question there is a difficult one, any good answer would be complicated and difficult to understand let alone write - hows your complex number theory ? ..... A simple (and probably incorrect )way to think about the input impedence is that a low one will try to suck more current out of the stage that feeds it - if the output impedence of the preceding stage is higher then it can't supply enough current, and everything goes pearshaped. If that stage is a buffer, then the buffer gets the current from battery - if its the guitar, then it 'loads' the pickup which knackers the tone and response. I kinda get it, and for normal everyday stuff like transistor and op-amp stages, there's loads of info available so its simple enough to get a rough idea whats going on. The LM13700 is a different beast - current amplifier - I can't find any rule of thumb about how to work out the input impedence (i think it's dynamic anyway?). IF the input impedence is high enough and you didn't want to buffer the main output, you could scrap the buffers completely in my latest design, and have just the AGC and Poweramp stages.... (btw, the LM13700 is available as an SMD) cheers Col Link to comment Share on other sites More sharing options...
col Posted September 27, 2006 Report Share Posted September 27, 2006 National and Maxim both do a range of low power mono 'filterless' class-d amps (all have maximum supply of 6v) - good examples are: MAX9700 and LM4673. These really do have minimal part counts... Maybe run the whole kaboodle @4.5v from 3 AA cells (assuming the LM13700 can be run from 4.5v - it can from 5v). It should be possible to get some unity gain buffers to run within 4.5v without clipping the peaks (i think?) col Link to comment Share on other sites More sharing options...
psw Posted September 27, 2006 Author Report Share Posted September 27, 2006 Your right of course... I think I'll stick to the driver technology for now. My circuit works and should be more than adequate to test different driver forms on it...when time and means permit. National and Maxim both do a range of low power mono 'filterless' class-d amps (all have maximum supply of 6v) - good examples are: MAX9700 and LM4673. These really do have minimal part counts... It's hard not to get excited about that stuff. I liked the way the driver would not be connected to earth too with D class amps and so create some isolation perhaps. There are a whole bunch designed for mobile phones with Compression and Preamps on board...some of them in stereo! My circuit could be improved and I have devised a simple op-amp stage and very small lm386 stage for a buffer/preamp/amp/driver modular system today, as mentioned as an idea in a post above. I just need to work out the best way for the whole system to be installed (switching and such) and I think this would be an improvement. Obviously, there would need to be a lot of testing which I am not able to do just now, so I'll keep that under wraps. I should mention that the layout creator is a fantastic program for nutting out small circuits on veroboard and I am having much fun playing around on it. I might even try and nut out a Fetzer / Ruby Layout so that people have something clear to work with. The program already comes with a layout for the ruby so a few adjustments shouldn't be too hard!!! (famous last words!) The driver is still the heart of the system IMO and reasons for it not working in it's current form (for some), easier manufacturing techniques of the driver and improvements in driver technology still need to be worked on. These are my stronger suits and I think I'd better stick to that... Your circuit ideas hold a lot of promise and I am keen to see them implemented...and try them for myself...but much can still be gained from driver design. Let's see what we can come up with and perhaps both aspects will come together at just the right time! Meanwhile...if anyone else has any bright ideas or questions regarding the project as it stands or how it can be better done...or simply to introduce yourselves and express your interest, we'd all be glad to hear from you I'm sure... pete No...number theory is not my strong point (I can solder though!!!) but you have helped me understand in your post a little there and I think that a preamp, or at least a buffer will be a must. Some circuit refinements are possible, and you are on the right track...if you can vibrate the string with less power (as you seem to be doing with your minimum gain LM386 as opposed to my maxed out one) then it stands to reason that you are generating less EMI (even if you are having some problems at this point). Perhaps your very thin, 2mm coil is even better than my 3mm coil in this regards. As far as circuitry goes, perhaps you could use some filtering of very high frequencies as this may be where your "fizz" or EMI problems lie. The coil itself will have resonant frequencies and there may be RF or other artifacts in the drive signal that are causing interferance (especcially since you have the circuit spread out on a bread board). I recall now that in one version of my present circuit I used a ferrite bead on the driver leads...ah, here's a pic... Astute followers of the thread may recognise it as being from the era of the tailpiece "sustain box" thing that Tim and Emre were so active in designing (way back when). For those that missed it, this would sit behind the bridge. The sensitivity knob could be pushed in for momentary activation. At one point I had a low battery indication light circuit and of course it drove a ultra small hex driver with 5 LED's!!! who cares about battery consumption!!! Actually I think that the Hex driver principles were more effective and so less power consuming than our comparatively big coils, but they were not really that practical. I still occasionally try to think of a manner in which to salvage the technology (there was no coil winding involved at least) but the alignment and havoc with string bending with the driver anywhere but at the bridge really did mean it was impractical...oh well Link to comment Share on other sites More sharing options...
ebenezer shred Posted September 27, 2006 Report Share Posted September 27, 2006 Still at it E. shred!!! Hmm... Haven't been on this thread in a while, glad I did. I was wondering if there was some way (going back to psw's sustainer idea) I could just put a driver in the guitar, then have the board and everything in a pedal on the floor. Is this possible? (never mind if it's impractical to building it into the guitar) We have discussed this option in various ways...there are some major problems...you may need to run two leads to the guitar...one for the driver and the other for the signal to the amp. Mixing them could cause a lot of problems with EMI from the cables themselves. You would also likely need more power, but this would be less of an issue as it wouldn't need to run off batteries! I looked at various ways that everything could be mounted in a surface mounted box (like a tailpiece) with a very small surface mounted driver. The problem is that you would still need (except for a single pickup guitar I suppose) major rewiring and bypass switching inside the guitar. The photo of my "sustain box" on the LP in the above post, and pictured off the guitar here... may appear to be just what you are talking about, but it isn't really! This is a testing device...there is no bypass switching and the driver is not permanently mounted to the guitar, nor the neck HB function properly as it is lowered so much to fit the driver on, and the other coil not compensated...that it does not function too well. It is a replica though of the driver and circuit that is in my guitar and a useful device none the less...but not really for playing. There are some sounds of the thing on the sounds thread, but it did not work as well as it does on a fully installed guitar like my strat. UPDATE: Playing my strat just now with ulta clean sounds to get the "fizz". This is not EMI. I think that this is amplification of high pitched fret buzz and loose components and such! In order to get the harmonics to ring loud and true, the amplifier needs to be set so as to reproduce such high sounds...consequently you need a lot of treble and headroom to get these kinds of sounds. You can do it quitely with some compression for instance but this brings out the background noises (like this "fizz"). It does not sound in fundamental mode on the same settings....I think...because the full bodied sound of the whole note (not just the higher artifacts) overwhelms these things and the strings vibration is more natural. More needs to be done to look into it more fully, but that is what appears to be going on. Bear in mind also, that I am talking a very sterile clean sound...nothing very attractive about it...almost painfully brittle and high fi and not something you would naormally choose to play music with in the real world. Only a slight bit of hair (would still be regarded as clean) is required to give body to these high harmonics and eradicate the "fizz" effect!!! So...it does appear to work ok...I wish to build another, better quality sustainer guitar in the future that will shed more light on things I guess... pete This seems like something I would be very interested in experimenting with perfecting. I was thinking about making an out of guitar sustainer system so I didn't have to route and I could switch it from guitar to guitar, and attatch it to the strap or something. And I do just have a single pickup guitar. Do you think you could send me a schematic of your sustainer in a box system? I would very, very much like to experiment with this idea. Link to comment Share on other sites More sharing options...
psw Posted September 27, 2006 Author Report Share Posted September 27, 2006 This seems like something I would be very interested in experimenting with perfecting. I was thinking about making an out of guitar sustainer system so I didn't have to route and I could switch it from guitar to guitar, and attatch it to the strap or something. And I do just have a single pickup guitar. Do you think you could send me a schematic of your sustainer in a box system? I would very, very much like to experiment with this idea. Ahhh...there's that question again.... I don't have a schematic, it kind of evolved...the photo above is pretty similar to what is in it, and is in my guitar too...just variations. But they are just simple preamp/amplifiers... For now the "standard circuit" is the Fetzer/Ruby and this should work in the same way! In fact, this is what I suggest all people do, it is effectively what col and tim are doing. Make the circuit, make the driver and try it outside of the guitar before you even think about installing it. The "sustain box" plugs into the guitar jack and a line is taken out to the amp as well as to the circuit within. A lead is attached to the driver and you can test it by holding it over the strings, or if there is room, under them. You could make room by removing or adapting the neck pickup... Once you know you have a working driver and circuit, then you can look at how you could implement it into a guitar, or even if you'd want to. It will also give you a sense of the problems associated with it, and why, although it will sustain, the box ultimately wont give you quite what you are looking for in a performance instrument. Unlike stompbox "effects", a sustainer system is an intergral part of the instrument and will change it. But for starters, this will certainly "work"... So, without problems there would be no solutions. I'd build a Fetzer/Ruby and a suitable driver and see what you can come up with, without modifying the guitar. But, like me, you will find that it won't really be complete until it is installed and playing properly. BTW, you don't have to have a neck pickup under the driver, just stick a magnet on there...you need to have the controls all the way up...and away you go... Hope that helps... pete Link to comment Share on other sites More sharing options...
col Posted September 27, 2006 Report Share Posted September 27, 2006 I'm going to try building a circuit on perfboard now. The updated kinda worked. Unfortunately I couldn't get a satisfactory configuration with just unity buffers at the input as I'd hoped, so I'm back to using a gain stage. The variable 'DynamicRangeInverter™' curve seems to be working though, so there is more control and some of the settings are cool, but with coolness comes more noise :-| So, I'm hoping that getting away from that nest of wire ariels, parasitic capacitance and dodgy connections I call a breadboard and onto a good compact soldered board will help... will have to just wait and see I've also unearthed a pickup from an old junk box. Its a 'reflex blues' active bridge humbucker that I bought decades ago on impulse at a sale, only to find that the preamp was missing from the box - it's never been used .. If I get no joy perfboarding the circuit, I might have a go at setting up this pickup for some tests... It's dc resistance is 2.3k compared to the 16.4k of my DuncanJB In other news, I'm wondering if trying to use a transformer to isolate the circuit might be a bad idea - adding more coils to try and fix coil related issues seems a little daft... So I've been looking at 'opto-isolators' as a possible alternative - does anyone know anything about them ? @pete I had another go at running my setup with no buffer for the straight through signal - it worked ok, so I'm not sure what went wrong before. The tone was noticably weaker though, possibly just a side effect of all the bare wire connecting everything up... Anyhow, I have a few more things to try Col Link to comment Share on other sites More sharing options...
spazzyone Posted September 27, 2006 Report Share Posted September 27, 2006 (edited) Im almost done recording samples (downstairs neighbor limits my time) i had to put the "Pickup" in my ibanez as it has the best fret dress of all my guitars. But while my high E sustains its fairly soft. Its a 10 gauge and i tried a 13 B string it improved but still to much tension. so i shifted the notes to the B string on the ibanez. As its 24 frets so it just makes it (on with or without you). As for Eurpoa does anyone know how i can slow it down a little without changing pitch? its good as a sample but if i can "stretch it " i can realy make the sustainer sing. Thanks Edited September 27, 2006 by spazzyone Link to comment Share on other sites More sharing options...
psw Posted September 27, 2006 Author Report Share Posted September 27, 2006 So, I'm hoping that getting away from that nest of wire ariels, parasitic capacitance and dodgy connections I call a breadboard and onto a good compact soldered board will help... will have to just wait and see I think there should be an improvement...keep those driver leads twisted and relatively short...but well awy from the pickup also! I've also unearthed a pickup from an old junk box. Could be the start of another project looking into active low impedance pickups! It would be a shame if the sustainer project had to use special pickups, but I really like my pickup driver combo and I think there are a lot of things learnt in dealing with sustainers that can be directly applied to pickup development. A part of this is the development of construction techniques and the availability of materials for pickup designs outside of the norm. The bobbinless driver / pickups are intriguing, as are tiny magnets and varying coil depths, coil orientation and multiple coils. I worked out a way, for instance, to attach tiny magnets to a ball bearing as a pole piece inside a metal tube (cut from a steel rivet), where the magnet inside the tube (about 2mm deep) could be adjusted up and down within the tube. You could also load the pickup with more magnets from the back if you wished to increase magnetic power...looked pretty cool too! Some things are a bit fanciful...like my LED driver (I copped a lot of flack for that, it was at a time that off the forum it was said to be a fake!). In laying out a separate amp module to sit close to the driver, I realized that the best place to take power for an LED is from there and the easiest place to put it is in the driver itself (no holes required). You could also run the LED from an amplifier so that it lights only when the sustainer is on...and sustaining! People who are experimenting with this project can try this for a laugh...connect an LED to the driver wires and watch it light up when you play...neato. It might even take less power to do this than to have the light on all the time! Spazzy...there are special programs for slowing tracks down on the computer for practicing and stuff...can't remember any names...but you can do it with a sampling program, record to your computer and stretch the time on the entire track Anyway...a bit busy, but the mind is always active. Will be concentrating on looking for easy ways to make drivers and new driver ideas and will post some for brainstorming when I get some time to draw them up. Unfortunately, I am still trying to find a place to live and get my stuff back, but when I do there is plenty of "junk" to go through and I will no doubt get out that sustain box and try out some weird ideas like this "wave" driver. The "wave driver" concept may be able to drive the string with those hex driver elements (probably 12) with no direct pull on the string, be 4mm deep including magnets and not involve coil winding. It has a unique orientation of both dual magnetic fields and elements that should radically help in EMI reduction. The device will need to be heatsinked to stop burning out, but the magnets should help in that. The question will be, is it possible to make an alnalog of the strings vibration below the string that would directly correspond. Any system that can exploit real time resonance could work with very little power....I don't think this will be quite that effective (a la wine glass breaking resonance) but possibly quite effective in itself. Anyway...good to here there is progress there col and I hope the layout goes without any major glitches... pete Link to comment Share on other sites More sharing options...
ebenezer shred Posted September 27, 2006 Report Share Posted September 27, 2006 Could I possibly just build the ruby, and use that preamp from guitar fetish to run it like a fetzer? I would like doing that rather than the fetzer/ruby because there is a perfboard layout of the ruby on run off groove. Link to comment Share on other sites More sharing options...
col Posted September 28, 2006 Report Share Posted September 28, 2006 Could I possibly just build the ruby, and use that preamp from guitar fetish to run it like a fetzer? I would like doing that rather than the fetzer/ruby because there is a perfboard layout of the ruby on run off groove. There's no real 'magic' to designing a layout. If you're building stuff that works with radio waves or microwaves, then layout can be critical, but for simple low power audio circuits, it's just not as important. You should have a go, it's good fun to see how much you can squeeze into a small space . You don't need fancy software either, I just use a pencil, eraser and pad of squared paper. The fetzer ruby is a small simple circuit, a great choice one for a first attempt at a layout. Generally, try to keep the input away from the output. A good start is to put components in roughly the same positions as they are in the schematic.... Col Link to comment Share on other sites More sharing options...
psw Posted September 28, 2006 Author Report Share Posted September 28, 2006 There's no real 'magic' to designing a layout. This is not verified or a complete circuit...but, a poweramp module supplied for power by the preamp module...and even then it needs a little more work for the concept. Otherwise it is the LM386 circuit that I am using in the strat (or should be)... If you follow that link under the pic, you will find the free program DIY Layour Creator and it's fantastic to work with. It will do vero board like this, perfboard (just holes) or PCB's without all the fuss of schematic drawing. It really is easy and a lot of fun. When you are there you can download all kinds of effect box circuits, including the Ruby. Actually, if you were using one of those commercial preamps, you may well be able to drive the thing with something as small as the circuit above. Obviously you would cut this down to the area around the components and this is at least twice the size of the real thing...it really is the smallest and easiest part of the circuit. Give it a go...or wait some, and I will eventually get around to laying out the fetzer / ruby circuit for the sustainer projecteers Out of interest, the buffer preamp circuit I made was not much larger than this anyway. The buffer part could be optional (or switchable) and the preamp runs from it with a variable gain and a very basic filter. I also put in the power cap and circuit protection diode and LED resistor, but now I'm thinking the LED may best be put on this circuit, or both! The sensitivity control, harmonic switch and bypass switches should go between these modules if possible. The preamp will require some more work, and testing. I'm actually thinking that a quad opamp may be the go, different preamps for harmonic and normal drive (using the + and - inputs) a buffer and a boost for the main signal... See how easy it is to get carried away...until you have to build the thing and it doesn't quite work as planned Good luck pete Link to comment Share on other sites More sharing options...
col Posted September 29, 2006 Report Share Posted September 29, 2006 There's no real 'magic' to designing a layout. This is not verified or a complete circuit... No **** :D It seems that you have some pins mixed up? pins go from the blob at the top left downwards 1, 2, 3, 4 then from the bottom right pin upward: 5, 6, 7, 8 ...In this layout, you have the output connencted to nothing, the bypass pin connected via a cap to 'out+', ground pin unconnected etc. The interesting thing though is that you have some chunky caps in there - 100u seems ok for an output cap, and 10u from pin1 to pin8. However C4 seems a little large and (assuming this is the intention) a 10u from pin7 to ground is a very large value! If this is what you have in your circuit, that would explain why you have to run with such a high gain to get any response - a normal value for that cap I guess would be somewhere between 0.001u and 0.1u. (If this is what you use, maybe it's what gives you less noise, I doubt it though) Can you verify what values you are using ? and which pins ? I'm doing some stripboard layouts, the idea being that although the will be a little larger, and more noise prone, they will allow much easier modifications. Rather than one for the whole board, I'm doing the 3 stages seperately. Once I have double checked them for errors, I will post them... or maybe I should wait until they are built and verified... cheers Col Link to comment Share on other sites More sharing options...
psw Posted September 29, 2006 Author Report Share Posted September 29, 2006 This is the original schematic I believe...and yes that is a 10uF from Pin 7!!! hmmm (the output has been changed to 100uF and the 1k 1-8 pin resistor omitted for max gain. The 100uF cap is intended to go on the preamp) Now, see...that is the danger of doing and especially posting a layout without checking it, building it, proving it. I posted solely for the purposes of demonstrating how easy it is to use that program and layout parts...seems I showed how easy it is to get it wrong!!! I see what I did wrong...in condensing the circuit, I moved the ground rail and left off a ground connection...it's almost right, but oh so wrong. A couple more tweaks required. Interesting point about the 10uF from 7 to ground. In the app notes on the 386, the only time this cap is specified is in an AM radio circuit and it is a 10 uF but otherwies it is a cap in dotted lines. I know that it can be run without it, and others often specify it as being linked directly to ground. The effect of a large capacitor and it's consequence on gain (gain/power consumption?) I don't know. Interesting...maybe I could do with less power / less gain ... or maybe you could do well to see the effect of adding it for less noise. Pete Link to comment Share on other sites More sharing options...
col Posted September 29, 2006 Report Share Posted September 29, 2006 Now, see...that is the danger of doing and especially posting a layout without checking it, building it, proving it. I posted solely for the purposes of demonstrating how easy it is to use that program and layout parts...seems I showed how easy it is to get it wrong!!! Heh, I guessed it was mostly a demo - just don't want anyone to build that layout and expect it to work Interesting point about the 10uF from 7 to ground. In the app notes on the 386, the only time this cap is specified is in an AM radio circuit and it is a 10 uF but otherwies it is a cap in dotted lines. I know that it can be run without it, and others often specify it as being linked directly to ground. The effect of a large capacitor and it's consequence on gain (gain/power consumption?) I don't know. Interesting...maybe I could do with less power / less gain ... or maybe you could do well to see the effect of adding it for less noise. Yes, it's an interesing point, my limited understanding is that anything above the frequency response of that cap will be attenuated - kinda guesswork based on the pin being called 'bypass' and looking at the chip schematic in the datasheet. What I initially thought was that if the cap on pins 1 & 8 is the same as the bypas cap, then your only trying to put gain on the frequencies you've already setn to bypass... But thinking it over some more, I guess that the cutoff slope is very gentle.. and its never as simple as it first appears So, I will have a play around with that cap - and try your 10u value For what its worth, I did have some problems with parasitic oscellations at one point, and I put a 4.7n cap there - fixed it completely. Col Link to comment Share on other sites More sharing options...
psw Posted September 29, 2006 Author Report Share Posted September 29, 2006 For what its worth, I did have some problems with parasitic oscellations at one point, and I put a 4.7n cap there - fixed it completely. or maybe the "fizz" is some how related to it...the only time I get "fizz" is when amplifying and driving harmonics with a very clean sound. The amplifier is trying to deal with very high frequencies in the driving signal. pete Link to comment Share on other sites More sharing options...
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