lok Posted April 6, 2009 Report Share Posted April 6, 2009 would anyone help me to wire the driver, amp and my JEM555, which is H/S/H ?? coz i hv no idea of those colorful wires... sorry that i live in HK, so it is a bit difficult for me to read through all pages from the beginning to 307... the only thing i don't understand yet is the circuit of my guitar... (bcoz u guys are mainly using the strat... ) thx a lot!! Link to comment Share on other sites More sharing options...
Donovan Posted April 6, 2009 Report Share Posted April 6, 2009 That's a shame, I was looking forward to having someone with a more scientific approach to share ideas and results with. well, good luck anyway Col Please don't be discouraged. I appreciate what you're doing. Though it's slightly over my head I read regularly and enthusiastically. I look forward to reading more of your results with this new circuit and seeing a preliminary dwg when you're ready. I've been keeping quiet here (as I am sure many others are as well) as I "learn" some more basics and tinker. Link to comment Share on other sites More sharing options...
col Posted April 6, 2009 Report Share Posted April 6, 2009 Please don't be discouraged. I appreciate what you're doing. Though it's slightly over my head I read regularly and enthusiastically. I look forward to reading more of your results with this new circuit and seeing a preliminary dwg when you're ready. I've been keeping quiet here (as I am sure many others are as well) as I "learn" some more basics and tinker. Thanks. I'm not too discouraged - still working away here More stuff in development at the moment, it shouldn't be too long before there's something worth posting to the group. My new driver works, but the LM386 is not the right output stage. Not because its noisy, although that doesn't help. It's because it can't drive a 2.5ohm load efficiently so the benefits of reducing the DC resistance are wiped out. As a result, I'm busy learning how to 'design' a discrete push-pull output stage. Its going well at this point. I am concerned that when it comes to building and testing, I'll have problems with thermal runaway and other issues that are hard to solve without experience and suitable equipment. You never know though - it might all just work... lol My super simple AGC worked, but not well enough, so I've hacked together another one which is still un-tested. Plenty to do before its time to go public. cheers Col Link to comment Share on other sites More sharing options...
col Posted April 6, 2009 Report Share Posted April 6, 2009 would anyone help me to wire the driver, amp and my JEM555, which is H/S/H ?? coz i hv no idea of those colorful wires... sorry that i live in HK, so it is a bit difficult for me to read through all pages from the beginning to 307... the only thing i don't understand yet is the circuit of my guitar... (bcoz u guys are mainly using the strat... ) thx a lot!! First of all, have you built and tested your circuit and driver ? if not, then do that (a few times probably) before even thinking about installing into a nice axe. Secondly, AFAIK, no-one has successfully installed a sustainer based on the designs here on a H/S/H guitar. There are a number of potentially significant hurdles to overcome. I suggest that folks swap out the neck humbucker for the driver and live with not having a neck pickup. Or better still, get a cheapo second guitar to do sustainer experiments with - at least until you have it all working perfectly with other pickups etc before tearing apart a beloved favorite guitar. cheers Col Link to comment Share on other sites More sharing options...
mrjstudios Posted April 8, 2009 Report Share Posted April 8, 2009 Well, I've still been looking in and reading up on the thread every now and then.... I haven't deserted Col: I think the work you are doing is very solid. In a completely coincidental and unrelated way, I seem to have experimented and confirmed some of your results earlier on. I was working towards a much simpler and different purpose at the time, but the things you are discovering about wire thicknesses and also the overall impedence of the coil make lots of since to me now by dumb luck! My first successful driver was a .25mm/30AWG driver wound to about 5-6 ohms, driven by a 386, and the only driver I ever had that topped it was one I made much later based off of PSW's driver concept. Had I been able to make that first driver to the same quality as I made the much later PSW design driver, who knows how well it could have worked, although it shouldn't work that well logically. I also had a more radical 4 ohm driver (dual coil) at one point that seemed to kinda work well in some facets, but I think the fact that I was still using a 386 to drive it was the problem. At the time, I dismissed its problems as poor driver design, but with your great new discoveries now I'm wondering if that was really it.... at that time I understood significantly less about circuits, and so I probably overlooked some of the power stage's problems with driving about 3.85 ohms. Anyway, great work. Link to comment Share on other sites More sharing options...
Hank McSpank Posted April 9, 2009 Report Share Posted April 9, 2009 (edited) Here's the latest summary for my build... The story so far... LM386 - tried as a power amp. but quickly ruled it out - I saw too much distortion across the driver on a scope. I also reckon that the external component count is just too high (with chunky caps too) for a hex driver. (I should point out that I tried the LM386 very early on & it may have been me at fault)) TDA7284 - tried this chip as AGC circuit (Eeugh! Once again it might have been me, but in my opinion, this one is best left to the lo-fi cassette recorder circuits for which it was intended!) TDA7053A - a stereo power amp chip with DC Volume Control ....low distortion, but erratic results were experienced when using just the one channel (eg inter channel current discrepancy shutdown protection etc) TDA7052A - (a mono version of the above) much better, but a cheeky little gotcha with this chip (vs the TDA7053A) - the DC level for its Volume control is achieved inside the chip (using an external variable resistor - you can't just apply your own DC Voltage which you can with its bigger sibling). I'm still not 100% sold on the TDA705x chip series - the quiescent current is a little on the high side & certainly it's not that efficient when it's cranking. My next 'chip of choice' is actually class D chip ...I just need to work out how to solder 8 wires onto a package that measures just 3mm x 3mm! (I'm hoping that my 'soon to be finished' DIY CNC build will help in this area!). For now though, I'll work with the TDAs. My early conclusions are that a *decent* guitar sustainer defintely needs to produce a distortion free signal (as seen across the driver) ... the TDA705x meets that requirement, so I can push on. IMHO ...the next ingredient that's absolutely key, is a flexible (& accurate) AGC/limit & threshold circuit. Without one,, most homegrown sustainers will liekly need regular tweaking to try & get a good balance of sustain across the strings (& up/down the fretboard) After pondering this AGC/control aspect for far too long, I've decided to use PIC. So, today I've just finished a small 'AGC framework' program for a PIC16F690...this will monitor a DC level presented at one of its input pins (this DC level will actually be a 'rectified' signal level as derived from the analogue guitar signal level taken after the the preamp). The PIC converts this DC level to 8 bits digital ...this then permits *major* flexibility - because once we're in the digital domain, it's easy & quick to tweak things like the guitar signal threshold, optimum signal level (also release, attack etc). Also, using a PIC as AGC etc, still gives me hope I can still go Hex, as the component count will be quite low & the control options very flexible. The output from the PIC is a PWM pulse train - fed into a Low Pass filter (which sounds grand, but it's just a resistor & an electrolytic cap!), ultimately resulting in a variable DC level - depending on whether the incoming signal needs higher/lower gain as observed at the preamp output). I intend using this PIC o/p DC level to feed onwards to a JFET - this JFET controls the preamp gain (a VCA). I'm out to buy some JFETs today to implement this latter bit tonight (JFETs are a brave new world for me, so I'm sure there'll be some issues!). Re my driver - well, I've not given up on the single string hex driver idea yet! I've finally got *all* strings sustaining very well using a single string driver using just 0.1mm wire** - for now, this wire is wrapped around an 8mm 'cut up' nail (the nail body is 3mm in diameter - flat head). To the nail's head I've attached three very small neodymium magnets (3mm x 0.5mm). It performs well. All my testing is back to being done with a sig gen as an input to the circuit board. So why have I gone back to the Sig Gen? Well, simply to remove a lot of the 'transients' & claim back a degree of 'control' (those who have experimented & been frustated at the somewhat erratic results, should appreciate what I'm saying here!). Actually what I have discovered in using a sig gen vs the actual guitar signal, is that in many ways, it's easier to get the strings to excite with the guitar signal - because the fundamental frequency is *exactly* the same - whereas you have to be absolutely bang on with the sig gen frequency or you'll get very poor results. (the driver is still chucking out a horrific amount of EMI when being fed with a sig gen ...for reasons which I've still not got to the bottom of...I can only assume it's because a sine wave represents the 'perfect storm' from a driver's EMI perspective!) Overall, I'm happy enough with progress thus far...still a *lot* to do though! ** I'm still not conviced that 0.2mm (& above) diameter wire is needed for the six string driver - certainly for the current draw I'm seeing with a single string driver, even 'scaling up', I reckon 0.2mm wire would seem overkill), so I'll be making six string driver with 0.1mm wire over the coming days to see how that performs. Edited April 10, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
TheEdge Posted April 9, 2009 Report Share Posted April 9, 2009 sorry for changing a bit the discussion..but, about the driver, the copper wire has to be "enameled", or can be used also common 0,2 wire like this: http://www.banzaieffects.com/Copper-wire-0...27372.html#tabs ? Link to comment Share on other sites More sharing options...
col Posted April 10, 2009 Report Share Posted April 10, 2009 sorry for changing a bit the discussion..but, about the driver, the copper wire has to be "enameled", or can be used also common 0,2 wire like this: http://www.banzaieffects.com/Copper-wire-0...27372.html#tabs ? The wire must have insulation. So basically, the only suitable wire that's readily available is 'enameled' wire. cheers Col Link to comment Share on other sites More sharing options...
space_ryerson Posted April 10, 2009 Report Share Posted April 10, 2009 I like the way you're thinking Hank! I was actually contemplating either an Arduino or DSP based AGC/lag circuit recently, in a similar line of thinking. I look forward to hearing how it works out. Link to comment Share on other sites More sharing options...
zfrittz6 Posted April 11, 2009 Report Share Posted April 11, 2009 (edited) TDA1011 Edited April 12, 2009 by zfrittz6 Link to comment Share on other sites More sharing options...
psw Posted April 12, 2009 Author Report Share Posted April 12, 2009 Hmmm...looks familiar... Aussie Compressor 2006 Hi guys...great thread, great project... Can't make one at the moment to experiment but this circuit has been raised a few times over at the Sustainer Ideas Thread at Project Guitar for possible modification into an improved sustainer circuit... http://projectguitar.ibforums.com/index.ph...mp;#entry293444 Presently we typically use a preamp and LM386 to drive a "thin" coil under the strings to create infinite sustain. In another thread here, member col has been looking into various compressor like circuits to even out the response of different strings and action in relation to fretting position... http://www.diystompboxes.com/smfforum/inde...w;topicseen#new Anyway...the question is, could this circuit be modified to be used to provide compression but provide enough output to drive a speaker (a la the ruby) or, in our case, a driving coil! Obviously things like the output cap (I use a 100uF) and the gain between pins 1 & 8 could be adjusted and some more components may be required for stability in a high gain mode... Any thoughts? pete Brought to the attention of the thread at the time...just saying...more posts, more changing posts, no explanation but apparently a return to single drivers and LM386's...feel I am in a time warp...but as you can see I feel I have said enough over the years to initiate work on the project and get results of this kind...my participation is seldom required I suspect... pete Link to comment Share on other sites More sharing options...
Hank McSpank Posted April 13, 2009 Report Share Posted April 13, 2009 (edited) For the sake of a bit of balance here (why so rude?), zfrittz6's last schematic, whilst *very* similar, does have quite a few different value components (and some extra ones) I read that aussiemart compressor thread from beginning to end - what a mess (about 5 different permutations, errors on the schematics etc). I'm not sure anyone got the thing working 'as expected' & looks like it eventually fell by the wayside. Who's to say that the aussiemart OP (Brett) didn't just see a similar circuit somewhere else himself & then post it up with a couple of his own mods? (my point being, in this internet age where things get posted, cross posted, modifed, rejigged, re-shared, remodified etc....it's easy to see how replication can pop up) Also some aspects of the aussiemart compessor were at best vague (MOSFET variant), whereas zfrittz6's has the MOSFET shown - maybe zfrittz6 nailed the design? I would have liked to have seen some supporting text from him, but hey, he's Spanish & if I was posting on a Spanish forum, I wouldn't have posted up much in the way of accompanying text in either! You have to remember there aren't *that* many ways to control an Opamp's level (automatically) & most decent variants use either a MOSFET OF JFET either in the feedback loop or at the opamp input (as it goes, here's one I've just found that looks promising as it works off just 5V...which is exactly the VCC level of my present line of attack - (sire from circuit posted up from - http://www.holmea.demon.co.uk/Spread/Spread.htm While I'm here, here's my first handwound 6 string driver (literally! ie holding in one hand & winding with the other - no jigs, vices etc). I used 0.15mm wire ....the core metal is about 1mm thick "L" shaped - taken & cut up from a general metal scrapbox (I think this metal was originally something to do with a PC's PCI bracket - anyway, it's ferrous!) just potted it with paraffin wax- it'll have it's first trial run tonight (I thought I'd embrace being European & place a Euro nxt to the driver to show scale) My single string drivers (0.1mm wire) are sustaining the strings well (including top 'E' & 'B' strings, just honing the supporting AGC circuitry...last night I was investigating whether the AGC works best applied at the power amp chip or the preamp chip. With the poweramp chip I'm using (A TDA7052A), AGC worked best there, but I really want to get the AGC working better at the preamp stage as that's where I'd prefer it went (better interfacing with with for example Roland GK pickup boards etc) Edited April 22, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
col Posted April 13, 2009 Report Share Posted April 13, 2009 For the sake of a bit of balance here (why so rude?), zfrittz6's last schematic, whilst *very* similar, does have quite a few different value components (and some extra ones) I read that aussiemart compressor thread from beginning to end - what a mess (about 5 different permutations, errors on the schematics etc). I'm not sure anyone got the thing working 'as expected' & looks like it eventually fell by the wayside. Who's to say that the aussiemart OP (Brett) didn't just see a similar circuit somewhere else himself & then post it up with a couple of his own mods? (my point being, in this internet age where things get posted, cross posted, modifed, rejigged, re-shared, remodified etc....it's easy to see how replication can pop up) Also some aspects of the aussiemart compessor were at best vague (MOSFET variant), whereas zfrittz6's has the MOSFET shown - maybe zfrittz6 nailed the design? I would have liked to have seen some supporting text from him, but hey, he's Spanish & if I was posting on a Spanish forum, I wouldn't have posted up much in the way of accompanying text in either! Agreed. Although, I've set up simulations of the various versions of the aussie mart, and of zfrittz's version, and none of them do anything like a suitable AGC for this project. Of all of them, only one of the ones in the aussiemart thread works at all, and it is little better than an asymetrical clipper. You have to remember there aren't *that* many ways to control an Opamp's level (automatically) & most decent variants use either a MOSFET OF JFET either in the feedback loop or at the opamp input (as it goes, here's one I've just found that looks promising as it works off just 5V...which is exactly the VCC level of my present line of attack - Yes, jfet or vactrol seems to be the way... apart from stuff like VCAs and LM13700 type circuits. That circuit diagram you posted is a very simple basic afair - the only thing thats not bog standard seems to be that the fet is attached to the positive rail rather than to ground. There are a number of problems with that type of circuit. Particularly the reaction times can be higher than we would like, and distortion at low frequencies can also be bad. Here are links to the three best circuits I've found for using a jfet as a basis for AGC. a simple 'fet attached to feedback loop' design a very nice 'carefully biased fet attached at input to op-amp' a snazzy but tricky twin fet circuit that keeps the fets in their linear region. (click on the print friendly one to get a version with the diagram and text together) I really like that third one, but I'm worried about the trouble I (and others) will have matching and selecting devices and then tweaking the result without a scope. I've been back working on my old circuit, updating it a little. I've spent a lot of time recently on various other attempts, but the original is still best by some margin. It is a combination of the first two of those three designs. It uses the clever jfet biasing from the first article 'fast peak limiter', but uses it in the feedback loop of an op-amp similarly to the that second article. In addition, rather than taking the control voltage from the output of the op-amp, I'm using the circuit input, rectified and scaled as a control voltage. I've been able to increase the size of the band between threshold and limit compared with my earlier design, and make some improvement to the reaction speeds of the circuit. I'll be testing soon. Hopefully I'll have some good news. It will output a fairly even output level for inputs between about 70mV peak to peak and about 220mV peak to peak. above and below those, the output level drops. The input has a gain control so the circuit can be adjusted to control this range. This allows it to work with different pickups, although if you increase the low level sensitivity, the upper limit is reduced. You can find earlier versions with basically the same approach posted in the thread. While I'm here, here's my first handwound 6 string driver (literally! ie holding in one hand & winding with the other - no jigs, vices etc). I used 0.15mm wire ....the core metal is about 1mm thick "L" shaped - taken & cut up from a general metal scrapbox (I think this metal was originally something to do with a PC's PCI bracket - anyway, it's ferrous!) just potted it with paraffin wax- it'll have it's first trial run tonight Good to see you're having a bash at the 'standard' design - albeit your own variation. ...Heh, I've found that the best stuff fo a core is the plate they use to make the chassis for pc power supplies. It is very magnetic (as you would expect - it needs to provide shielding). Its thin so good for laminations, and it's soft enough to cut up with a pair of tin snips. My single string drivers (0.1mm wire) are sustaining the strings well (including top 'E' & 'B' strings, just honing the supporting AGC circuitry...last night I was investigating whether the AGC works best applied at the power amp chip or the preamp chip. With the poweramp chip I'm using (A TDA7052A), AGC worked best there, but I really want to get the AGC working better at the preamp stage as that's where I'd prefer it went (better interfacing with with for example Roland GK pickup boards etc) I've also wondered and messed about with applying the AGC to the power amp, but so far not fount it to be as easy, as 'good' or as practical. I got it to kind of work with the LM386, but it was no where near as good as the pre-amp versions I've hacked together. Might be good with a vactrol though... and that might also provide a super minimal circuit. The problem with the jfets is that the range of resistance that they can provide linearly is too puny to be useful with the LM386. Vactrol might work in this respect. I like the idea of keeping the power stage and the rest of the circuit separate - this should make it easier to swap out different power circuits to test. enough for now cheers Col Link to comment Share on other sites More sharing options...
Hank McSpank Posted April 13, 2009 Report Share Posted April 13, 2009 (edited) Yes, jfet or vactrol seems to be the way... apart from stuff like VCAs and LM13700 type circuits. That circuit diagram you posted is a very simple basic afair - the only thing thats not bog standard seems to be that the fet is attached to the positive rail rather than to ground. Exactly - as an aside, just about all decent AGC Circuits I've seen require a dual rail approach - The lazy/simple approach would be to go the Quad VCA SSM2164 route, but alas even that in single ended mode, still needs at least an 8V control voltage (& I'd prefer to stick with my 5V rail), that's why I liked that simple AGC - it's works with 5V & it's simple ....the 'detail' wrt my AGC comes from the PIC (there's lots of decisions going on in there!). There is a new fantastic 5V 8 channel digitally controlled audio fader chip that would interface wonderfully with my PIC - http://www.cirrus.com/en/pubs/proDatasheet/CS3318_F1.pdf ...but it's 48 PIN SMT (& bloody expensive at about £20) There are a number of problems with that type of circuit. Particularly the reaction times can be higher than we would like, and distortion at low frequencies can also be bad. That's a good point, but with my intended route, the reaction time (in this instance the JFET's controlling DC level) will be controlled by altering the duty cycle on a PIC PWM output stream - this ought to make for a little quicker control. What I did notice last night is that when increasing the power amp gain level (manually), there's a critical point where the whole circuit 'bites' & it starts exciting the string well, but that *very* rapidly runs away & turns into squeal....the conclusion here being is that any AGC will need to be somewhat 'clever' & lightning quick to get to that point of 'bite' but back off quick enough so that the squeal doesn't kick in. In my opinion, that's a tall order for the DIY discreet component route (though it's obviously do-able as there are already commercial solutions out in the market). I also have a hunch, that the driver can be 'right' next to the other pickups, *if* you can control that AGC well (& darned quick)...I reckon the squeal isn't so much a by product of EMI (though obviously it is changing magnetic flux ffields that are the conduit), but more a by-product of unecessary power being applied to the driver (& across all strings) resulting v quickly in uncontrolled positive feedback...in short, I reckon if you nail the AGC (ideally with a smaller drivers ...eg three string, two string or one string variants)), you're well on the to full 'squeal control' , which leaves you with a lot more options with respect to driver placement. btw, I can't open the snazzy last cct, as I'm just getting spammed with adverts, & it doesn't take me past them - even when I click on the "Take me to, blah blah")), or at the very least most need a 9V rail (in order to get enough headroom to get into a JFET's pinchoff area). Edited April 13, 2009 by Hank McSpank Link to comment Share on other sites More sharing options...
col Posted April 13, 2009 Report Share Posted April 13, 2009 Exactly - as an aside, just about all decent AGC Circuits I've seen require a dual rail approach Although its often a trivial job to set them up to work with a single rail and a virtual ground - that's what I've done. That's a good point, but with my intended route, the reaction time (in this instance the JFET's controlling DC level) Ah, of course, I was forgetting that you are intending to use this in combination with a PIC, so its a DC level that you want to vary. What I did notice last night is that when increasing the power amp gain level (manually), there's a critical point where the whole circuit 'bites' & it starts exciting the string well, but that *very* rapidly runs away & turns into squeal....the conclusion here being is that any AGC will need to be somewhat 'clever' & lightning quick to get to that point of 'bite' but back off quick enough so that the squeal doesn't kick in. In my opinion, that's a tall order for the DIY discreet component route (though it's obviously do-able as there are already commercial solutions out in the market). I also have a hunch, that the driver can be 'right' next to the other pickups, *if* you can control that AGC well (& darned quick)...I reckon the squeal isn't so much a by product of EMI (though obviously it is changing magnetic flux ffields that are the conduit), but more a by-product of unecessary power being applied to the driver (& across all strings) resulting v quickly in uncontrolled positive feedback...in short, I reckon if you nail the AGC (ideally with a smaller drivers ...eg three string, two string or one string variants)), you nail the problem of squeal, which leaves you with a lot more options with respect to driver placement. Unless you're trying to get really close to the pickup, you should be getting fret rattling sustain well before you get into squeal territory. As far as needing a clever AGC, as long as you use a feed-forward topology, you should be able to set it up to ease off the drive as the input gets to 'strong sustain' levels a little bit of fun with the PIC should achieve this with no trouble. btw, I can't open the snazzy last cct, as I'm just getting spammed with adverts, & it doesn't take me past them - even when I click on the "Take me to, blah blah")), or at the very least most need a 9V rail (in order to get enough headroom to get into a JFET's pinchoff area). hmm, Heres a link to the diagram - maybe that will work? cheers Col Link to comment Share on other sites More sharing options...
Dogue Posted April 13, 2009 Report Share Posted April 13, 2009 I've read a fair amount of this thread and also searched. Forgive me if a similar situation has already been addressed. Basically, my goal is to run a plurality of DIY Ebows on somewhat of an acoustic zither. I'm trying to do this in the easiest possible way, and thus far have had acceptable results running a telephone pickup coil with small neodymium magnet attached -> LM386-based amplifier -> small audio output transformer with modified cores and neodymium magnet attached I want to run many of these (at least 12) close to each other. This presents in my mind two possible problems: 1) EMI from adjacent sustainers may adversely affect performance 2) Magnetic attraction between adjacent sustainers will be logistically annoying From what I've heard, the original Ebow's coils were put in ferrite cups of some sort to minimize unwanted EMI. Would it be possible/advantageous to use EMI ferrite core filters (often intended for ridding EMI in wiring) over each pickup and over each driver? This would obviously bulk up the apparatus. Suggestions? Thanks a lot. Link to comment Share on other sites More sharing options...
psw Posted April 13, 2009 Author Report Share Posted April 13, 2009 Well...I built several variants on the simple aussiemart comp (not just simulations)...the thread there was a development thread with people chipping in to develop a relevant use of the LM386 for this project. Once you get a feel for the circuit and hear it, it is relatively easy to tweak by ear and response without a "scope"...we are talking pretty simple circuits here. Connect a speaker in place of the driver and you will hear the AGC clamp down on the signal, we really are just talking about a simple switch are we not, none of the AGC stuff hanging off there is in the signal chain, the output and zener are simply a trigger, the rest just determines threshold and release times of the switch...I don't see where additional distortion comes into it other than the LM386...but then it need not be an LM386 and any triggering discrete would achieve much the same result. Yes, the zener senses asymmetrically from the output and at high gains, the components need to be changed to deal with that...but once triggered the jfet or mosfet of choice simply acts as a switch. So, attaching a speaker you can hear that once a certain threshold is reached, the switch turns the input to the lm386 off (it also doubles to avoid loading issues without an additional preamp stage). The same principle could be done within a preamp stage with an opamp, but the economy of this simple design was certainly attractive to my approach. The time of release is set by the caps. It can be set to be quite a hard limiting device with very long release times...to none at all. But it is only triggered asymmetrically, it cuts gain completely. Such an action may be just wrong for general compression duties and require finessing as a stomp box, but in our application such hard limiting may well be found to be useful. ... My nose is still out of joint regarding recent events and I guess that seeing these various pics that seem to have evolved to a single coil driver and an LM386 circuit with a basic AGC of a type brought forward by me back then and developed off site, could be used to further lionize such things and denigrate my work, or at least co-opt the development credit. AGC was always seen to be of some importance...squeal indicates to me some fatal flaws (at the very least fizz, even if it is controlled in the silences)...but AGC was always on the cards. I showed that very early on I used various compressors as preamps but replicating such things into a compact circuit that could be practically used in this application was impractical. The AussieMart application of the LM386 certainly opened up some doors for me for ways of achieving that...but I credited the design genesis where due back in 2006. But, the current climate indicates a general feeling that AGC and such things are to be credited with others, and that the aussiemart principle (it was explored further in a more developed form in subsequent threads I think over there) may well be credited elsewhere also. ... I guess the proof is in the results, mine are on the board...better things may well come and I encourage that, but I fear that these pics are there purely to continue the lionizing of something that seems to morphing ever closer to things that were explored and achieved 3 years back and may well be construed to be new developments or improvements to the basic design. A design that while simple, took me a fair amount of effort to achieve and still more to support and help others to achieve and seems in recent months to be suggested are of little consequence. This I feel is an underestimation of the achievement...hence still feeling somewhat sore about that. A "time warp" because I feel that this has largely been seen and discussed a long while back. ... There are plenty of things that can be done, different directions people may go...a lot of different criteria that people obviously set themselves. I just thought I ought to annotate that pic post to put it in the historical context of this thread and the origin of the uncredited circuit design and driver (by all appearances) that were shown as the current incarnation. Personally, I find such posts "rude" or at least pointless other than another shot across the bows and politically motivated. Spanish or not, what was the point of this contribution? That single coil drivers and basic AGC of a type I pointed to 3 years ago was worth pursuing? If so, I guess I should be flattered, but in the recent context, I still don't feel that way about it and for the lack of any annotation, thought it deserved clarification before someone reemerges to claim credit on another's behalf without having read or been involved in the thread at that time. ... But then, I suppose so is posts like this answering such things...so I'll sit out some more I guess. Unfortunately, it would appear that some will miss out on the usual help that could achieve a working device with a basic coil and amp setup and we will see a continuation of emails to me or posts elsewhere on PG seeking such advice...or simply be put off by the need for scopes and circuit design chops just to get something half working. That I do feel is a shame. This one for instance...LINK or this...LINK...both largely gone unanswered in recent times as a result recent attitudes, including my own I will grant you, and that has certainly put me off repeating the same kind of advice again and again, or having to defend such advice that others have found helpful in the past to get the thing working and yet no one else seems bothered to support. I offered such support in the hope that once someone has got something working, they may well be the ones to improve things further and to support people into the future and keep this thread going. So, I am disappointed I guess at the way things have turned, or so it would seem to me...but it wouldn't be the first time such things have occurred, I am just a little less tolerant at this point in time. Link to comment Share on other sites More sharing options...
psw Posted April 13, 2009 Author Report Share Posted April 13, 2009 I've read a fair amount of this thread and also searched. Forgive me if a similar situation has already been addressed. Basically, my goal is to run a plurality of DIY Ebows on somewhat of an acoustic zither. I'm trying to do this in the easiest possible way, and thus far have had acceptable results running a telephone pickup coil with small neodymium magnet attached -> LM386-based amplifier -> small audio output transformer with modified cores and neodymium magnet attached I want to run many of these (at least 12) close to each other. This presents in my mind two possible problems: 1) EMI from adjacent sustainers may adversely affect performance 2) Magnetic attraction between adjacent sustainers will be logistically annoying From what I've heard, the original Ebow's coils were put in ferrite cups of some sort to minimize unwanted EMI. Would it be possible/advantageous to use EMI ferrite core filters (often intended for ridding EMI in wiring) over each pickup and over each driver? This would obviously bulk up the apparatus. Suggestions? Thanks a lot. I think you have rightly seen some of the problems. The thing to consider in shielding, especially over the top of the drivers is that the EM energy coming out of the driver is what makes the thing go! As a result, if it is contained a lot or completely, this will drop efficiency (requiring more power and putting you largely back where you were) or not work at all (as the EMF (force) will not be working on the strings either) if fully contained. Crosstalk may well be an inevitable result of the multi-driver approach, however, you still may get a working result from such experiements. In the ebow, there are steel (I believe) sheilds from the back and sides allowing the driver and pickup to be relatively close. However, if you put another beside it, the likely hood is the pickup from one will pick up the signal from the driver of the the other. This could be cured bu further distancing the pickups and drivers perhaps much as is done with a sustainer...the more drivers, the further the distance. On a zither I imagine though, you have the whole string length to play with and perhaps such distances (the pickups on one end and the drivers on the other) may well be possible as no fretting is required. If you get it working, you might consider some kind of damping mechanisim so that it could be played by releasing strings (taking off a felt damper perhaps as in an auto harp) and letting the sustainer "play" the string for you rather or in addition to plucking. Just a few thoughts...while I'm about pete Link to comment Share on other sites More sharing options...
Dogue Posted April 13, 2009 Report Share Posted April 13, 2009 (edited) I've read a fair amount of this thread and also searched. Forgive me if a similar situation has already been addressed. Basically, my goal is to run a plurality of DIY Ebows on somewhat of an acoustic zither. I'm trying to do this in the easiest possible way, and thus far have had acceptable results running a telephone pickup coil with small neodymium magnet attached -> LM386-based amplifier -> small audio output transformer with modified cores and neodymium magnet attached I want to run many of these (at least 12) close to each other. This presents in my mind two possible problems: 1) EMI from adjacent sustainers may adversely affect performance 2) Magnetic attraction between adjacent sustainers will be logistically annoying From what I've heard, the original Ebow's coils were put in ferrite cups of some sort to minimize unwanted EMI. Would it be possible/advantageous to use EMI ferrite core filters (often intended for ridding EMI in wiring) over each pickup and over each driver? This would obviously bulk up the apparatus. Suggestions? Thanks a lot. I think you have rightly seen some of the problems. The thing to consider in shielding, especially over the top of the drivers is that the EM energy coming out of the driver is what makes the thing go! As a result, if it is contained a lot or completely, this will drop efficiency (requiring more power and putting you largely back where you were) or not work at all (as the EMF (force) will not be working on the strings either) if fully contained. Crosstalk may well be an inevitable result of the multi-driver approach, however, you still may get a working result from such experiements. In the ebow, there are steel (I believe) sheilds from the back and sides allowing the driver and pickup to be relatively close. However, if you put another beside it, the likely hood is the pickup from one will pick up the signal from the driver of the the other. This could be cured bu further distancing the pickups and drivers perhaps much as is done with a sustainer...the more drivers, the further the distance. On a zither I imagine though, you have the whole string length to play with and perhaps such distances (the pickups on one end and the drivers on the other) may well be possible as no fretting is required. If you get it working, you might consider some kind of damping mechanisim so that it could be played by releasing strings (taking off a felt damper perhaps as in an auto harp) and letting the sustainer "play" the string for you rather or in addition to plucking. Just a few thoughts...while I'm about pete Pete, thanks a lot for the reply. Yes, I do have basically the entire length of the string to work with, so I can space out the drivers and pickups. In initial experiments there haven't been any noticeable detrimental phase or other effects on having significant distance between the drivers and pickups. Do I need to worry about pickups effecting adjacent pickups and drivers effecting adjacent drivers? I suppose this is the EMI issue. Not necessarily this exact one, but this is the general type of ferrite core I had been considering trying out for EMI shielding: http://www.radioshack.com/product/index.js...oductId=2103222 If I had a pole piece extending such that the magnetic field extended close enough to the string as possible, perhaps it would work. However, having not used one of these ferrite cores before, perhaps that wouldn't work, since perhaps it diminishes the magnetism irrespective of whether it is unwanted interference or not. In fact, I'm now trying it on a piano, and so I can control the sustainers via the sustain pedal (appropriately enough) or individual keys. Edited April 13, 2009 by Dogue Link to comment Share on other sites More sharing options...
col Posted April 13, 2009 Report Share Posted April 13, 2009 Well...I built several variants on the simple aussiemart comp (not just simulations)...the thread there was a development thread with people chipping in to develop a relevant use of the LM386 for this project. Once you get a feel for the circuit and hear it, it is relatively easy to tweak by ear and response without a "scope"...we are talking pretty simple circuits here. Connect a speaker in place of the driver and you will hear the AGC clamp down on the signal, we really are just talking about a simple switch are we not, none of the AGC stuff hanging off there is in the signal chain, the output and zener are simply a trigger, the rest just determines threshold and release times of the switch...I don't see where additional distortion comes into it other than the LM386...but then it need not be an LM386 and any triggering discrete would achieve much the same result. Yes, the zener senses asymmetrically from the output and at high gains, the components need to be changed to deal with that...but once triggered the jfet or mosfet of choice simply acts as a switch. So, attaching a speaker you can hear that once a certain threshold is reached, the switch turns the input to the lm386 off (it also doubles to avoid loading issues without an additional preamp stage). The same principle could be done within a preamp stage with an opamp, but the economy of this simple design was certainly attractive to my approach. The time of release is set by the caps. It can be set to be quite a hard limiting device with very long release times...to none at all. But it is only triggered asymmetrically, it cuts gain completely. Such an action may be just wrong for general compression duties and require finessing as a stomp box, but in our application such hard limiting may well be found to be useful. I've emboldened some parts of your reply for clarity. I'm now going to be really blunt because I don't want my point to get lost in the detail. and its late. #1 small parts count does always equate to simple. #2 The whole reason for AGC is because a 'simple switch' is not enough. (if it was, we'd use a simple switch right?) #3 if the 'AGC stuff' is not in the signal chain, then it is completely redundant. It must be in the signal chain to alter the amplitude of the signal. #4 If you don't see where the distortion comes from then you're not even beginning to understand how this 'pretty simple' circuit works(or doesn't). #5 something that is triggered asymmetrically and cuts gain completely is little better than a diode clipper. Which is exactly the results I described in my previous post. A diode clipper* would at least offer symetrical clipping, and would have a lower parts count. If you have a version of this in your sustainer and it doesn't add fizz or distortion to the signal, then it is not 'kicking in' while you are playing... which would explain the steadily rising volume of the sustain that you described recently - that definitely would not be happening with a crude hard limiting device like this applied to the signal). *I'm not advising anyone to use a diode clipper as a limiter in their sustainer - any kind of hard clipping, symetrical or otherwise will add unacceptable distortion to the output of your guitar - assuming it is set up to kick in at signal voltages. cheers Col Link to comment Share on other sites More sharing options...
psw Posted April 14, 2009 Author Report Share Posted April 14, 2009 I think you will find that it is not distorting the signal into or out of the LM386...nor does it effect the guitars signal (what I mean by it not being in the signal chain). Basically, the signal in to the sustainer circuit is cut for a period of time set by the cap effectively and at a point set by the zener diode threshold...this turns the discrete off and on. SO, basically a switch. In a normal signal it would be bad, but since the momentum of the string carries on when sustaining and it can be set below "pumping" it does have application in this circuit. There is no "fuzz box" hard signal clipping at all, the diode is just there to set the trigger to cut the input, the output signal does not go through it. My circuit has a intensity control that allows for the threshold and gain to be adjusted...so on full "drive" there is effectively no AGC...but some people like that effect, including me. Turning it down will kick it in for more control, so I designed mine to cover a wider range of bases. There is also a trim pot to adjust the amount of drive and threshold for different guitars (the tele will go full blast with a new battery without squeal). But, it is crude and not feed forward, but as the circuit should be transparent (ideally) it does that job. Basically it senses the output (if we see this as generally symmetrical, the fact it triggers off of one side of the wave form does not really matter, as long as it triggers)) and triggers over a set point (the resistor into the diode threshold) which is the trigger for the switch (fet)...so no signal distortion, not in theory, nor in practice. It will turn back on when the output drops below this threshold and the cap drains (avoiding stuttering). The risk is that you can get a stuttering effect if the thresholds aren't set right...but that is more like tremolo than any kind of distortion. Again, even then, the momentum of the strings, which is all you are really hearing, carries through any of that...we are not talking large hold times really and there is no clicking or popping on switching of the gate. Basically the diode will only trigger if a voltage at the output exceeds a certain amount...at that point, the threshold set buy a resistor (perhaps softened by a cap) will send a control signal to the fet shutting off the input...at that point it is off and wont come on till the cap discharges (setting the time and saving power too)...the momentum of the string carries through and you don't here the circuit shutting off with this application. #4 If you don't see where the distortion comes from then you're not even beginning to understand how this 'pretty simple' circuit works(or doesn't). I beg to differ of course...look again the diode is the trigger and not in the signal path except to trigger the fet off, cutting off the input to prevent overloading the input and distorting (depending on the amp and the thresholds of course). #5 something that is triggered asymmetrically and cuts gain completely is little better than a diode clipper. Which is exactly the results I described in my previous post. A diode clipper* would at least offer symetrical clipping, and would have a lower parts count. Nope...no clipping, completely different application...the fet also acts as the buffer and neither the aussiemart nor the spanish version is what I am doing...but pretty much a similar principle. This saves many components that a preamp would normally require if only to prevent loading. Listen to the clips... and the results, or ask for a test sample...and you will hear (or not) the effect. Mine does fizz on high gains, but then the AGC is over-ridden and is intentional...but it is also adjustable if not to your taste. I have built a few variations on this theme and with no AGC at all. If you are getting distortions with a simulation, then perhaps there is something wrong there...basically it is working like a noise gate...and if you have a non-popping switch on you sustainer, you can simulate the effect with a switch... But then, you say I don't understand, I say I do, I have built them, I heard them, and shown that it works in principle, so have quite a few with the compressor application (hardly a clipping device)...so what would I know right? Link to comment Share on other sites More sharing options...
col Posted April 14, 2009 Report Share Posted April 14, 2009 I think you will find that it is not distorting the signal into or out of the LM386...nor does it effect the guitars signal (what I mean by it not being in the signal chain). It obviously effects the guitars signal or it couldn't alter the volume of it. Basically, the signal in to the sustainer circuit is cut for a period of time set by the cap effectively and at a point set by the zener diode threshold... The circuit schematic you posted a diagram of in response to zfrittz post has NO zener diode. There is no "fuzz box" hard signal clipping at all, the diode is just there to set the trigger to cut the input, the output signal does not go through it. The signal doesn't have to go through the diode for the diode to cause distortion - the signal doesn't go through the diode in a diode clipper either. My circuit has a... Ah, so your response to my post discussing the aussiemart circuit wasn't about the aussiemart circuit, but about a different circuit. The aussiemart circuit is supposed to be a compressor, and does work as a crude compressor in exactly the way I described. But you proceded to argue that I was wrong, but are basing this on a completely different circuit that you have 'bent' out of one of the aussiemart ones... We cannot have a constructive discussion about how your circuit works because it is SECRET. Any analysis I have made has been based on the public aussiemart circuits. Basically the diode will only trigger if a voltage at the output exceeds a certain amount...at that point, the threshold set buy a resistor (perhaps softened by a cap) will send a control signal to the fet shutting off the input...at that point it is off and wont come on till the cap discharges (setting the time and saving power too)...the momentum of the string carries through and you don't here the circuit shutting off with this application. We have discussed the merits of this approach more than once before in the thread, I understand the concept. This is not how the aussiemart circuit you posted is intended to function. #4 If you don't see where the distortion comes from then you're not even beginning to understand how this 'pretty simple' circuit works(or doesn't). I beg to differ of course...look again the diode is the trigger and not in the signal path except to trigger the fet off, cutting off the input to prevent overloading the input and distorting (depending on the amp and the thresholds of course). Differ all you want, you are wrong - the diode in the aussiemart circuit is not a 'trigger' it is intended to function as a half wave rectifier. It may be doing something different in your circuit, but that is irrelevant unless you're going to publish it. #5 something that is triggered asymmetrically and cuts gain completely is little better than a diode clipper. Which is exactly the results I described in my previous post. A diode clipper* would at least offer symetrical clipping, and would have a lower parts count. Nope...no clipping, completely different application...the fet also acts as the buffer and neither the aussiemart nor the spanish version is what I am doing...but pretty much a similar principle. This saves many components that a preamp would normally require if only to prevent loading. Ah, so you're admitting it now that you're refuting my analysis of the circuit you posted by referring to a different circuit that works in a different way - at least we've cleared that up. Col Link to comment Share on other sites More sharing options...
psw Posted April 15, 2009 Author Report Share Posted April 15, 2009 You are right, it's three years ago and there were numerous variations...this particular aussiemart circuit that I posted as to the similarity to another does not feature a zener but a different diode, Both work (with appropriate mods and value adjustments)...yes half way rectifier...to trigger the mosfet in that case as a switch (in it's most simple form)...it is still not a clipper circuit, but a triggering device for the MOSfet to cut the input signal. Not what I no as a "clipper circuit such as a tube screamer, but a level limiter as described. Here is one description from the designer(s)... How it works: With small signal input, the mosfet is "off", and all of the signal goes to the op-amp, which puts out maybe 1 or 2 volts. With a large input signal, some of the output gets to about +3V, and a bit less gets past the diode and charges the cap. If the cap and gate get to 2.5 V, the mosfet conducts some signal to ground and lowers the output. No matter how large the input signal, the output never gets above +/- 3V. Regarding particular JFETs and MOSFETs. The J201 and a BS170 were what I used first time, and they worked well. The 2N7000 seems very close to the BS170, so it should be good, too. Any "normal" mosfet will work, because there's nothing fancy happening here. (Q) Essentially, the mosfet is going to behave very close to the led/ldr setup for most optical compressors, in that the mosfet can only source current, and without biasing the gate signal you're only going to be compressing the +ve side of each wave. (A) RE: Does it compress only half the signal? The 22uF capacitor and 1M "bleed" resistor hold the MOSFET "on" for a long while (a few seconds ?), so there's no rapid changes in the release of compression. In fact, it probably holds on a bit too long. Maybe the 4.7uF cap should be lower (1uF), or even switchable, depending on whether you are playing hard and fast (4.7uF is then ok), or playing a soulful solo and want "bloom" without waiting too long (probably want 1uF then, or reduce the 1M to 330k or 220k). .... but from me after watching that thread and others and doing some work of my own... g'DAY... Have been experimenting with variations on this circuit for the sustainer application...won't work as is, but certainly got me thinking in new ways about the problem and getting some headway...so thanks for all those contributing to this very interesting thread... Anyway...I think Brett mentioned it somewhere, this and compressors in general seem to be sensitive to power supply....given the higher gains I am using this is probably a lot worse (I use the LM386 as a Power Amp to driver a load with the sustainer), this seems to be particularly apparent. Are there any really simple (ie small) ways of stabilising the supply so that fluctuations in voltage or current do not effect function...from a 9 volt battery...that doesn't draw much of that power away or further drain it? I don't want to loose power in the process if possible or shorten battery life! Otherwise...have been inspired and helped by this to understand J and M FETS much better and transistors in general. Till now I have avoided discrete components favouring opamps for their lego like simplicity of constructing amp stages...also tricky to get some types. Speaking of which...is there a good site that gives substitutions? Any advice welcome... pete There was no SECRET about the directions I was considering, I was working from the site from people who designed and developed the thing and do have the expertise and scopes that I lack...no point posting or asking here now is there. I was talking about principles, not the minutia of particular values of components and directing to the known source of such uses of the LM386 (not me) because it should have been credited and put into context and wasn't. If I have or had made use of similar principles with different values and diodes, it is still the same principle and not what I would regard as a "clipping circuit" nor that of people far more knowledgable than I in that regard...have the debate with them if you seek such a conflict. Personally, the principle will achieve a compression effect, not a distortion (fuzz box clipper) effect and I have proven this to be so in practice. If that is not of interest to you, fair enough...probably wasn't then, maybe still not now. ... Well...I'll cut my pointless reply short I think...there was more explanation, however, clearly you are the better man Col, I should have credited you more with all that I have done here. Your simulations trump my reality and I can't go back 3 years over old ground with any reliability and clearly explain everything. Obviously if I were to "reveal" the circuitry I presently use, I would only be subjected to more abuse. Obviously the same is felt about any questions I have regarding others work too. Perhaps drivers that run as clear as a whistle yet still squeal exist and perhaps an AGC will correct that, I can't comment on that because of what I am not privy too either. None of that actually helps the average person who comes along with simple questions to get a simple device operational or who are looking for simple solutions within the scope of the average DIYer here. Obviously they are of little significance to the grand plans afoot. All the best with that, sincerely pete Link to comment Share on other sites More sharing options...
AndrewCE Posted April 15, 2009 Report Share Posted April 15, 2009 well its quite simple as long as you are not running your sustainers power supply in the audio. look at it this way. if you treat the guitar cable as a dc connecter adn an audio connector. it has two wires and it shares a ground. thats how the stereo cable works. but what you do is simply run the audio cable straight into the sustainer power supply in.. and then think tube amp. and decouple it to the guitar jack. let me draw something. the only real problem with this is an extra converter box to have the dc signal accept a guitar jack and then get converted to a small dc plug. when you stomp the switch it sends battery or wall wart regulated dc down the guitar cord to the guitar and the sustainor simultaniously so thats where the blocking cap comes in to block out the dc. i use a 1mfd film on both ends. as it lets my guitar sound come trhough decentlywhen you bypsass the box on the floor it cuts off the led.. not shown. and it bypasses the dc supply so your unit you are powering is effectively off. this is a great way to power emg's or active pickups. you can also do another trick and add xlr input and make it accept phantom power and use a 9v regulator that can handle it. probally need a voltage divider there but again thats a neat trick if you dont' need to source alot of current. most of my gear i build delivers around an amp for phantom power. but thats straight out max. but... then you'd have a dc voltage coming out of the first pedal in your chain? couldnt you electrocute yourself with that? can 9 or 18 volts electrocute you? it seems like a good idea as long as it's safe... Link to comment Share on other sites More sharing options...
col Posted April 15, 2009 Report Share Posted April 15, 2009 Here is one description from the designer(s)... How it works: With small signal input, the mosfet is "off", and all of the signal goes to the op-amp, which puts out maybe 1 or 2 volts. With a large input signal, some of the output gets to about +3V, and a bit less gets past the diode and charges the cap. If the cap and gate get to 2.5 V, the mosfet conducts some signal to ground and lowers the output. No matter how large the input signal, the output never gets above +/- 3V. What he is describing is exactly how all thes fet based compressors work, and how mine works, the fet is set up as a VARIABLE RESISTOR not as a switch !!!!!!!! This is the simple fact that you seem to be unable to accept. You may be using the fet in a different way, but if you are then your circuit works in a fundamentally different way, and it is not fair to base an argument of the former on experience of the latter. .... but from me after watching that thread and others and doing some work of my own... g'DAY... Have been experimenting with variations on this circuit for the sustainer application...won't work as is, but certainly got me thinking in new ways about the problem and getting some headway...so thanks for all those contributing to this very interesting thread... Anyway...I think Brett mentioned it somewhere, this and compressors in general seem to be sensitive to power supply....given the higher gains I am using this is probably a lot worse (I use the LM386 as a Power Amp to driver a load with the sustainer), this seems to be particularly apparent. Are there any really simple (ie small) ways of stabilising the supply so that fluctuations in voltage or current do not effect function...from a 9 volt battery...that doesn't draw much of that power away or further drain it? I don't want to loose power in the process if possible or shorten battery life! Otherwise...have been inspired and helped by this to understand J and M FETS much better and transistors in general. Till now I have avoided discrete components favouring opamps for their lego like simplicity of constructing amp stages...also tricky to get some types. Speaking of which...is there a good site that gives substitutions? Any advice welcome... pete I read this and it has nothing at all to do with using the fet as a switch, or anything else. Stabilizing the power supply is not too difficult, but requires extra components. It was explained in that thread how you could do it, and I have explained here how I do it more than once. Stabilizing the voltage feed to the fet is a different thing entirely, but for that, one option would be to do as I did in my design and use a full wave precision rectifier rather than a single diode. These questions you ask don't 'hint' or 'imply' anything much about different directions you might have been thinking about, or changes in approach to circuit functionality. There was no SECRET about the directions I was considering, I was working from the site from people who designed and developed the thing and do have the expertise and scopes that I lack...no point posting or asking here now is there. I was talking about principles, not the minutia of particular values of components and directing to the known source of such uses of the LM386 (not me) because it should have been credited and put into context and wasn't. If I have or had made use of similar principles with different values and diodes, it is still the same principle and not what I would regard as a "clipping circuit" nor that of people far more knowledgable than I in that regard...have the debate with them if you seek such a conflict. Personally, the principle will achieve a compression effect, not a distortion (fuzz box clipper) effect and I have proven this to be so in practice. If that is not of interest to you, fair enough...probably wasn't then, maybe still not now. Your self quote doesn't talk about minutia of components or about principles, is just asks about stabilizing the power supply - which would be a reasonable thing to consider for just about any electronic circuit - certainly not an innovation of any kind. As far as clipping - your at the old straw man again. I have not once said that the aussiemart is a clipping circuit. What I said was that it is little better than a clipping circuit. When used as intended, it imparts a lot of distortion to the waveform.So whether you regard you circuit as a clipping circuit it irrelevant - yet another red herring in your argument. ... Well...I'll cut my pointless reply short I think...there was more explanation, however, clearly you are the better man Col, I should have credited you more with all that I have done here. OK, if you want it that way, fine by me!! Typical of you these days, Pete, condescending, sarcastic, pig headed. No-one is trying to take credit for any of your ideas, or for the work yuo have put in. However, I do get pretty sick of the way you prattle on about stuff you don't fully understand, filling your arguments with haze and ambiguity. You get things wrong A LOT, I used to ignore it because you had a bit more respect for others, but its getting silly now. The way you've been attacking newcomers who make the faintest suggestion that some of the things you say might not be correct. Particularly how you attack people who want to use more sensible engineering methods and scientific process rather than spending hundreds of hours guessing and using trial and error to come up with something that works, but that they don't understand. It's sad, but if I pulled you up an all the errors and mis-information you have posted here over the years, the page count would be in the thousands. Your simulations trump my reality and I can't go back 3 years over old ground with any reliability and clearly explain everything. Obviously if I were to "reveal" the circuitry I presently use, I would only be subjected to more abuse. Obviously the same is felt about any questions I have regarding others work too. Perhaps drivers that run as clear as a whistle yet still squeal exist and perhaps an AGC will correct that, I can't comment on that because of what I am not privy too either. Oh dear, more sad attacks on the work of others, based mostly on ignorance. You used to want to help folk Pete. It seems that now you want to stop them in case they succeed without giving you full credit. None of that actually helps the average person who comes along with simple questions to get a simple device operational or who are looking for simple solutions within the scope of the average DIYer here. Obviously they are of little significance to the grand plans afoot. No, none of this helps anyone at all, but I'm not going to sit around and let you throw your weight around without saying anything. If you stop attacking folks unfairly, and you might find the atmosphere around here gets a lot more pleasant pretty quickly. cheers Col Link to comment Share on other sites More sharing options...
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