psw Posted June 21, 2005 Author Report Share Posted June 21, 2005 R.G. ... nice drawings Here are some FEMM plots I did in looking at my shunt's with staples vs without vs ceramic mag vs. neo-mags... Typical Ceramic ex-pickup magnet: Small Neodyminium Rare Earth Magnets: As above but with diversion fin's/shunts magnetised to opposite pole: These diagrams show that the shunts do indeed contain the field but also allow far less to exit to work on the string... My feeling was/is that on one hand you can reduce the amount of interferance with such shunts which will alow the use of more power...however...you'll need more power as less M-field is escaping the device to work on the strings... As I said...in practice there was very little difference in performance...with or without the fins...the prototype is still here and allows for all kinds of magnet changes and fin attachments if you'd like me to try something else with it... pete Link to comment Share on other sites More sharing options...
psw Posted June 21, 2005 Author Report Share Posted June 21, 2005 Now...I've mentioned the Hoover/Sustainiac Patent several times...here's a link: Patent Details - Text I can't send you direct to the drawings (need to have a suitable pdf viewer) but here's a brief description of the "shunts" I'm refering to... 5. The sustainer of claim 4 wherein said driver means includes: (a) a plurality of flux emitter means disposed in an end-to-end relation across said vibratory element for emitting said magnetic field, and; ( a gap narrowing means for narrowing a gap between at least two of said flux emitter means. I can only imagine, since these are only under the b and e strings that they serve a purpose other than to limit EMI (as that is emmitted equally from the whole coil)...I suspect therefore that the idea is to create a narrower magnetic field on these strings as the higher frequencies, manifest in smaller physical waves in the string, are better served by a tighter magnetic field...and this is their purpose... Anyone else have any ideas on this... It's interesting, as I said before, that, dispite their D class amps and super-tweaked circuitry, they still find room to look at fairly basic driver modifications for improved performance... Something to consider...people interested in sustainer technology and patents could well do with checking out this patent and the links from it...Mind you it makes this thread look like a pamphlet... psw Link to comment Share on other sites More sharing options...
psw Posted June 21, 2005 Author Report Share Posted June 21, 2005 One last post.... This should do the trick for switching power on and selecting bridge pickup with DPDT switch ("tone" side of pickup selector not shown): This will not affect tone side, so active tone controls will be selected with pickup selector. ← The above is Pekko's suggestion for implementing the sustainer bypass install...given the effects I've experienced, do you guy's think this will be enough to counteract them... Perhaps it will need a 3pdt switch to completely disconnect both hot and ground completely...also I'll still need the volume control...I had thought an earth lift...the Test Strat's electronics are a little complex and have gotten kind of messy with all the pickup changes and mods it's been through...I don't really want to have to rewire it or anything.... psw Link to comment Share on other sites More sharing options...
R.G. Posted June 21, 2005 Report Share Posted June 21, 2005 R.G. ... nice drawings Here are some FEMM plots I did in looking at my shunt's with staples vs without vs ceramic mag vs. neo-mags... These diagrams show that the shunts do indeed contain the field but also allow far less to exit to work on the string... My feeling was/is that on one hand you can reduce the amount of interferance with such shunts which will alow the use of more power...however...you'll need more power as less M-field is escaping the device to work on the strings... As I said...in practice there was very little difference in performance...with or without the fins...the prototype is still here and allows for all kinds of magnet changes and fin attachments if you'd like me to try something else with it... pete ← There are two ideas there. One - use a center blade/side wrapper to focus the field on the strings. This works best if the magnet itself is inside the coil, not powering the iron from the bottom of the stack. Otherwise, you do get high leakage from the middle of the iron stack out to the exterior wrapper before it gets to the area of space that the strings occupy. This is all going to work better with inherently long magnets like Alnico rather that short magnets like ceramic and near as I can tell, neodymium. You want the magnet to separate flux that comes out one end (north, for example) from that which comes out the other end. Alnico has best field strength if it's longer in the magnetic direction than it is wide. Ceramic works best if they're short and fat. The point of the close-to-the-coil wrapper is that it moves the magnetic gap from along the length of the magnet up to across the face of the magnet. It actually probably ought to have an opening like a blunderbus, so it makes it progressively harder for flux to jump from center to wrapper as it gets nearer the business end. This format forces more flux out to the space above the center lams than a tight wrapper does. Second, the focusing cup is not equal to the magnetic shunt. The magnetic shunt is some distance away from the whole magnet/coil affair, not connected to it at all. It's a garbage collector - it sucks up the stray field before it makes its way to another pickup. Half the distance to the next pickup is a good starting point. Link to comment Share on other sites More sharing options...
psw Posted June 22, 2005 Author Report Share Posted June 22, 2005 HELP...I just knew this switching was going to cause problems... Ok...installed pickups...wired the switch as per Pekko suggested (+ve battery to one side...hot pickup wires to the other.... The only thing I didn't do is connect the power side to anything (where Pekko's indicated ground...) Anyway all sorts of cancellations (depending on pickup/driver phase) and weird radio squelch type sounds.... The pickup and the driver work perfectly when wired without the other...as does the circuitry and everything...plenty of sheilded cable too and the bridge pickup is a stacked humbucker... Does this mean I need a 3PDT switch or something to lift both the earth and the hots....or would it help if I wired the earth leads to the sustainer selector rather than the hot leads.... please help...I'm so close....aghhhhh psw Link to comment Share on other sites More sharing options...
R.G. Posted June 22, 2005 Report Share Posted June 22, 2005 Now...I've mentioned the Hoover/Sustainiac Patent several times...here's a link: It's interesting, as I said before, that, dispite their D class amps and super-tweaked circuitry, they still find room to look at fairly basic driver modifications for improved performance... Something to consider...people interested in sustainer technology and patents could well do with checking out this patent and the links from it...Mind you it makes this thread look like a pamphlet... psw ← Hahahahahahahahahahahahahahahahahaha..hee..ho..ha... Oh, my sides ache. What a patent. That makes a number of things clear. - there are a few guys who are fairly nuts over magnetic sustainers working in the market - they hate one another - they think they're going to get rich by excluding others from building the Final Sustainer and having the world beat a path to their door. - they'll say or do anything to get there. Let's look at some things. - Prior art list. Ohmigod - SIXTY US PATENTS cited as references! - And the same names come up over and over and over. If you spend the money and time to buy a patent, you do NOT appreciate someone else horning in and trying to exclude you from some aspect you didn't think of yet. So these guys love each other. - Forty-seven claims with subparts, and I suspect when we see the drawings, circles and arrows and a paragraph on each one describing how they're to be used in evidence against ... someone... (sorry Arlo. ) Let's look at the more humorous claims: 1. A sustainer for a musical instrument... said sustainer comprising: ... (b ) a driver means having a plurality of flux emitter means... © a gap narrowing means for narrowing a gap between at least two of said flux emitter means. 2. The sustainer of claim 1 wherein said gap narrowing means comprises at least one of said flux emitter means having a portion overhanging a coil base means in the direction of said gap to narrow said gap. They claim that they have at least one pole pair to drive each string (b ) and they let the pole extensions get closer to some strings (narrowing the gap ). Well, duh. 3. The sustainer of claim 1 wherein at least one of said flux emitter means includes a plurality of prong means disposed between a coil base means and said vibratory element. And we take another full paragraph to point out that not only does the magnetic pole cup extend beyond the coil, it's separated into prongs. 4. A sustainer for a musical instrument having a body and a neck... (a) a neck pickup means (b ) a bridge pickup means © an amplifier means for providing a drive signal (d) a driver means disposed between said body and said vibratory element between said neck pickup means and said bridge pickup means (e) said neck means includes a nut (f) said bridge means includes at least one saddle means (g) an arrangement of said neck pickup means, said bridge pickup means, (1) a scale length dimension (S) (2) said dimension (N) (3) said dimension (M) (4) said dimension (B ) This means "We claim it works on ordinary style electric guitars with neck and bridge pickups". 7. The sustainer of claim 6 further comprising (i) a means responsive to vibration of said vibratory element for providing said signal responsive to vibration of said vibratory element, and (ii) a means having a plug means mateable with said jack means for conveying said signal through said jack means to an external amplification means disposed externally to said structure. Ohmigod!! (slaps forehead) we can use a JACK and PLUG to get the sound out to the amplifier!!! 8. The sustainer of claim 6 further comprising (i) an AC power supply means disposed externally to said structure means for providing said signal, and (ii) a means having a plug means mateable with said jack means for conveying said signal through said jack means to said amplifier means to provide power to said amplifier means. EGAD!!! We'll use an AC power supply with its own plug-and-jack to get powre in! Nobody's ever powered anything like that before!! 16. A sustainer ... comprising... © a means for conveying said driver output signal to an external amplification means disposed externally to said structure; (d) a pickup means for providing a substitution signal responsive to vibrations of said vibratory element; (e) a sound modifier means operable on said substitution signal for changing harmonic content of said substitution signal to provide a modified substitution signal, and; (f) a means for substituting said modified substitution signal for said driver output signal. 17. The sustainer of claim 16 wherein said sound modifier means comprises (i) a pickup means for providing a pickup signal in response to vibration of said vibratory element, and (ii) a means for combining said pickup signal with said substitution signal. 18. The sustainer of claim 16 wherein said sound modifier means includes a filter. Near as I can tell, they just claimed to have invented a fuzz box with tone controls by using the switching mode of their driver amplifier. Cool. If we can't keep the driver output out of the signal to the amp LETS FEATURE IT!!! 25. A sustainer for a musical instrument having a structure for supporting at least one vibratory element, said sustainer comprising: (a) a rigid sheet of material positionable between said structure and said vibratory element, the sheet having means for supporting: (1) a first pickup means for providing a first feedback signal; (2) an amplifier means responsive to said first feedback signal for providing a drive signal, and; (3) a driver means for applying drive forces to said vibratory element in response to said drive signal; (b ) a means for conveying said first feedback signal to said amplifier means, and; © a means for conveying said drive signal between said amplifier means and said driver means. um... they've patented the pickguard holding pickups... 26. The sustainer of claim 25 further comprising: (a) said first pickup means includes a neck pickup means for providing a signal responsive to vibrations of said vibratory element; (b ) a bridge pickup means for providing a signal responsive to vibrations of said vibratory element; © said neck pickup means being disposed next to a neck means; (d) said bridge pickup means being disposed next to a bridge means, and; (e) an arrangement of said neck pickup means, said driver means, and said bridge pickup means wherein said driver means is disposed between said neck pickup means and said bridge pickup means. Translation: the sustainer goes between the neck and bridge pickups. Claims 27, 28, and 29 reinvent the pulse width modulator. 35. The sustainer of claim 33 wherein said amplifying valve means comprises a device selected from the group consisting of bi-polar transistors and field-effect transistors and junction field-effect transistors and insulated-gate field-effect transistors and metal-oxide semiconductor field-effect transistors and semiconductor transistors. Translation: "If you use a bipolar or FET to amplify your driver signal, you'll hear from our lawyers! You're violating our patent claim". Pity they didn't claim vacuum tubes, Gallium Arsenide FETs and Josephson junction devices too. Then there's some fun in the text description: Musical instruments generally provide a cavity for housing an output jack attached to a cover plate. The output jack provides a means for conveying the output signal from the pickups, (which are located inside cavities in the body of musical instrument), to an external amplifier and speaker. Most such output jack cavities are generally large enough to hold one conventional 9-volt battery. The invention provides means to utilize this cavity for both a battery and an output jack. Translation: "We're patenting the idea of stuffing the battery and driver inside the output jack cavity!! Look Ma! No routing!!" There's a whole mess on switched-mode drives. I'm not sure that the guys who invented PWM drive for servomotors would think this was too novel. I'm getting tired of typing. This style of patenting is one where you claim ownership of the moon, the stars, air, water, heaven and earth, then send nastygrams to everyone who walks, breathes, drinks or looks at the sky. You include enough claims that if a court invalidates some of them, you have a zillion others to fall back on. There are a few good points in there; not sure how novel they really are, but then a court is the only place where that can be determined. The novel bits are: - moveable magnetic shunts (I think that this qualifies as "obvious to one skilled in the art" as I came up with them on my own in about fifteen minutes, but only courts get to call this). You know, now that I think about it, I was a few centuries late. Back when sailing ships were made out of wood and the compas was up on deck, they used big chunks of iron to cancel out the effect of the cannons on the earth's magnetid field so the compass would read true. - using a layer of the coil as a shield; good idea, but it's been used in transformers before. I remember some transformer teaching stuff from the 50's using that idea. Reading patents as humor is usually rewarding; it can also cure insomnia. Link to comment Share on other sites More sharing options...
psw Posted June 22, 2005 Author Report Share Posted June 22, 2005 HELP...I just knew this switching was going to cause problems... Ok...installed pickups...wired the switch as per Pekko suggested (+ve battery to one side...hot pickup wires to the other.... The only thing I didn't do is connect the power side to anything (where Pekko's indicated ground...) Anyway all sorts of cancellations (depending on pickup/driver phase) and weird radio squelch type sounds.... The pickup and the driver work perfectly when wired without the other...as does the circuitry and everything...plenty of sheilded cable too and the bridge pickup is a stacked humbucker... Does this mean I need a 3PDT switch or something to lift both the earth and the hots....or would it help if I wired the earth leads to the sustainer selector rather than the hot leads.... please help...I'm so close....aghhhhh psw ← still need practical help...any ideas??? Link to comment Share on other sites More sharing options...
psw Posted June 22, 2005 Author Report Share Posted June 22, 2005 Now...I've mentioned the Hoover/Sustainiac Patent several times...here's a link: It's interesting, ← Hahahahahahahahahahahahahahahahahaha..hee..ho..ha... Oh, my sides ache. What a patent. That makes a number of things clear. - there are a few guys who are fairly nuts over magnetic sustainers working in the market - they hate one another - they think they're going to get rich by excluding others from building the Final Sustainer and having the world beat a path to their door. - they'll say or do anything to get there. Let's look at some things. - Prior art list. Ohmigod - SIXTY US PATENTS cited as references! - And the same names come up over and over and over. If you spend the money and time to buy a patent, you do NOT appreciate someone else horning in and trying to exclude you from some aspect you didn't think of yet. So these guys love each other. - Forty-seven claims with subparts, and I suspect when we see the drawings, circles and arrows and a paragraph on each one describing how they're to be used in evidence against ... someone... (sorry Arlo. ) Let's look at the more humorous claims: 1. A sustainer for a musical instrument... said sustainer comprising: ... They claim that they have at least one pole pair to drive each string (b ) and they let the pole extensions get closer to some strings (narrowing the gap ). Well, duh. 3. The sustainer of claim 1 wherein at least one of said flux emitter means includes a plurality of prong means disposed between a coil base means and said vibratory element. And we take another full paragraph to point out that not only does the magnetic pole cup extend beyond the coil, it's separated into prongs. This means "We claim it works on ordinary style electric guitars with neck and bridge pickups". Ohmigod!! (slaps forehead) we can use a JACK and PLUG to get the sound out to the amplifier!!! EGAD!!! We'll use an AC power supply with its own plug-and-jack to get powre in! Nobody's ever powered anything like that before!! um... they've patented the pickguard holding pickups... Translation: "If you use a bipolar or FET to amplify your driver signal, you'll hear from our lawyers! You're violating our patent claim". Pity they didn't claim vacuum tubes, Gallium Arsenide FETs and Josephson junction devices too. Translation: "We're patenting the idea of stuffing the battery and driver inside the output jack cavity!! Look Ma! No routing!!" There's a whole mess on switched-mode drives. I'm not sure that the guys who invented PWM drive for servomotors would think this was too novel. I'm getting tired of typing. This style of patenting is one where you claim ownership of the moon, the stars, air, water, heaven and earth, then send nastygrams to everyone who walks, breathes, drinks or looks at the sky. You include enough claims that if a court invalidates some of them, you have a zillion others to fall back on. There are a few good points in there; not sure how novel they really are, but then a court is the only place where that can be determined. The novel bits are: - moveable magnetic shunts (I think that this qualifies as "obvious to one skilled in the art" as I came up with them on my own in about fifteen minutes, but only courts get to call this). Reading patents as humor is usually rewarding; it can also cure insomnia. ← Very funny...I hoped you cut and pasted from the patent for all that....R.G. I think we can all take for granted that patents are there for legal protection...written in "patent-speak" to provide fuel for the lawyers and too bamboozal the DIY guys like us... It's true this and all the others spend a good 20 pages pretty much describing an electric guitar...they often site their own patents that repeat the very same thing even though they've already sited it...it's all very wacky...and most of it not at all useful....however... You can see for the uninitiated where their ideas have taken them...make judgements and move on... The movable shunts under the high b and e strings...the question remains, why...? It's clearly not for the purposes of containing the M-field as the whole device is emmitting that...! The idea had enough merit to actually manufacture the design while the mid-driver was abandoned...untill someone tries to do it, then...spriiiinnggg...like a tiger the lawyers will come... The idea of two opposing driver coils (was that this patent or one of there others) does have some merit for further exploration...not so much, IMO for their stated aims but to have coils of different characteristics (resonance, power, etc) to suit each coils assigned strings... The idea of using more efficient amplification...eg D-class amps....I don't know if they actually do use this new technology...they're probably just covering themselves.... These kinds of ideas are worthy of thought...even if you too imediately came to the same idea... BTW...there's a links post to various patents on page 7, I believe...if you suffer, as I do, from lack of sleep... The Heet Ebow patent is pretty straight forward...as is the elegant device...but even they couldn't help but spend perhaps most of the patent describing an impractical implementation of it as an onboard sustainer type device... BTW...the Ebow sells for about A$300 down here...of course you get a no pick sticker and a hippie like drawstring bag for it...but really.... Also...I'm a big fan of the Ebow as a design but it does restrict normal playing and is pretty much restricted to monophonic operations (one string at a time)... Phase cancellation was something discussed here early on and features in a number of patents...Floyd Rose (who claims to have thought of his sustainer system completely independantly from all other work in the area...ahem....) describes his approach to overcoming it through circuit trickery... Now is this an area that LK propositioned, that these circuit aspects were simply a device to validate the patent holder's claims over previous patents...hmmm... MR COFFEE is the only one I've heard say that he has completely dismantled and analysed the Sustainiac circuit, but he unfortunately declined furthering our work with it here...or anywhere else it would seem...that's unfortunate as it would have made it more clear if they're really just using a "fuzz-box" into a LM386 or similar amp to a coil of wire...just as we're doing...and the rest is hocus-pocus...or there was more to it... Nevertherless...until someone comes along with the knowledge and skill to explore these ideas...or at least pass judgement on them...I think that it would be a better investment, by most of us, at this stage at least, to explore the more approachable, hands on, driver design rather than trying to design around it's inefficiencies... The more ludicrous the claims within these patents...the more I suspect the smoke a mirrors...the more the essence is that these things are nothing more than an amplified signal from the guitar sent to a relatively simple (magnet and coil) electromagnetic driver... Making it better or a "final driver" may mean going way off into new territory with different ideas...like I did for a year with the Hex drivers I developed which did have many novel unpatented features...but, just the same, it may be as simple as finding the right kind (shape, magnet, resonance, resistance, core material...) of driver to make it work by means of simple amplification... Right now, I'm for the latter...from actual experiments...I have concluded that even the most basic device will work to some degree and that it can be improved upon by accentuating some features (the slim coil for instance) without the hocus pocus and smoke and mirrors of the patents... If there are good ideas in there, then steal 'em I say, but don't ignore them...every little bit helps in the quest..."the Final Sustainer"...meanwhile, the more people try their hand at building these crude, but working models, and report back, the quicker we'll get to being able to draw conclusions as to "a final DIY sustainer" I think... I'm sure Mr Hoover, et al, are aware of this work and are probably having a good chuckle at it, but we may well come up with something they haven't...of course I suspect they'll take this public domain research, tart it up in patent-speak and trot it off to their lawyers as soon as they realise that some of us have made progress... In the meantime...we get to have fun with our sustainer's at a fraction of the price...people don't make their own effects and guitars because they can't buy a guitar or effect...they do it for reasons of fun and reward that can't be bought so easily...that's what all this is about...I hope... Anyway, enjoy...thanks R.G. psw Link to comment Share on other sites More sharing options...
psw Posted June 22, 2005 Author Report Share Posted June 22, 2005 Just to bring the discussion back to installing the sustainer system....I'll obviously need to go back and check my wiring... Here's a link to the Sustainiac wiring instructions, etc. Sustainiac Installation Page They do use a DPDT switch and they seem only to cut the hot wires...of course they dont have a passive picup under their driver, the stealth plus uses the driver, amplified, to create a neck pickup when the sustain function is off. If anyones inclinded to check their diagrams out and help me with the installation process I'd be really greatful... If anyone is interested in seeing the complexities of getting this out of test mode into an actual playing instrument this is also a good place to start...the multi-colored spagghetti of wiring is enough to put anyone off...it's no wonder they suggest that they install it...at an added cost... Now...off to do my Tax (from the year before)...then maybe I'll heat up the soldering iron and try again...there's a few basic testings of individual functions that I guess I'll need to perform...PITA taking the scratchplate out between each test... Tests should include... ...bypass function switch is operating as it should (disconnecting all pickups, connecting bridge pickup ...driver and pickup work in guitar when other not connected (they appear to) while installed in guitar ...I'm not getting some short somewhere ... whether a 3PDT switch that lifted ground and hots would solve the problem (I'm thinking not as it would just seem to reconnect the earth anyway...but...) ...weather the proximity of the driver wires to the internal (albeit sheilded) signal leads is causing an interferance and need to be routed away from them (say through the trem cavity... If anyone else has any ideas...let me know...this part is so frustrating.....grrrrrrr Link to comment Share on other sites More sharing options...
lovekraft Posted June 22, 2005 Report Share Posted June 22, 2005 RG's take on that patent reminds me of Don Lancaster, whose take on patents has always been my attitude: All a patent does is give you the right to sue someone in a civil action. At some future date in a ridiculously costly, extremely drawn out and easily circumvented legal process. Nobody has ever "won" any patent litigation. The main purpose of patent fights are to cause more grief and harm to the opposition than you are causing yourself. Almost always, this purpose fails miserably. I also will always remember an interview with one of IBM's legal eagles (back in the heyday of software patents) in which, when asked about licensing patented software, he replied, "We don't license software - we break patents". Link to comment Share on other sites More sharing options...
psw Posted June 22, 2005 Author Report Share Posted June 22, 2005 (edited) But what about my switching problem.... Ok...a bit of preliminary testing seems to suggest that my bypass switch isn't exactly bypassing...not quite sure what it's doing yet...the complex wiring in the test strat (phase switching on the meck and mid pickups, series/parralell on the stacked bridge plus a blend knob for the mid pickup independent of the tone and 3 way pickup selector) makes for something of a birds nest in there...may need a total rewire once it's sorted... This could take a while to sort out...no one can see any reason that having one end of a pickup coil connected should cause problems...hmmmm... This guitar has no cavity shielding so the whole thing is wired in multi core shielded cable to reduce noise (it's actually very quite, considering) but it makes it a bugger to get in there and modify... There's nothing for it I guess but to find the time to go through the process one step at a time... Edited June 23, 2005 by psw Link to comment Share on other sites More sharing options...
psw Posted June 24, 2005 Author Report Share Posted June 24, 2005 This should do the trick for switching power on and selecting bridge pickup with DPDT switch ("tone" side of pickup selector not shown): This will not affect tone side, so active tone controls will be selected with pickup selector. ← ← Ok...one thing...and I think this may be IMPORTANT...at least with the pickup/driver combo...if not all drivers...the core, blade, whatever needs to be grounded...some signal seems to get into the system when it's not causeing some of my woes in installation... Secondly...there seems to be a fault in Pekko's above switch scheme...when "bypassed-sustainer on" is selected and the selector selects both pickups (centre position)...the hot of both the neck and bridge pickups are effectively wired together meaning that the neck pickup is not in fact "bypassed"...at least when the centre, both on position is selected...given the cataclismic noise that results...this is a serious problem...hmmm... now...anyone got any suggestions on a solution...if a 3PDT is the answer, how would I wire it do you think.... frustrated pete I'll add to the pictorials on making the driver/pickup as it's very difficult to join the earth lead to the steel core once it's wound...I'm still not quite sure if I've caused any damage to my prototype...and the connection is not that secure...definitely something to do before you wind around the steel.... Link to comment Share on other sites More sharing options...
R.G. Posted June 24, 2005 Report Share Posted June 24, 2005 I'll add to the pictorials on making the driver/pickup as it's very difficult to join the earth lead to the steel core once it's wound...I'm still not quite sure if I've caused any damage to my prototype...and the connection is not that secure...definitely something to do before you wind around the steel.... ← Fray a wire and glue it to the underside of the steel with conductive epoxy... Link to comment Share on other sites More sharing options...
psw Posted June 24, 2005 Author Report Share Posted June 24, 2005 OK…I've done it…well80% successfully installed the PSW Pickup/Driver Combo DIY Sustainer!! It's been a comedy of (unfunny) errors and it still needs some work but many of the installation hurdles have been overcome and the thing sustains away reasonably happily…but…well…more on that later… First…the switching problem…you can do it with a DPDT switch…but the wiring from the selector needs to be separated into two outgoing hot signals. One is the bridge pickup which can go directly to the pot (the selector will disconnect it in the neck position)….The other is for the neck and any other pickups (in my case the middle as well…this goes to the sustainer on switch as does another direct line from the bridge pickup (I took it from the selector). So…you have three shielded wires to one side of the DPDT switch the middle one is a line to the volume pot…this is connected in the "off" position to allow signals from the neck and middle pickups (if they have been selected…the bridge pickup is already wired directly to the pot). In the "on" position the bridge pickup direct line is selected…a line goes from this also to the sustainer circuitry…the other side of the DPDT switch connects the power up to the circuit. With this wiring when the sustainer is on the bridge is always selected no matter what position the selector is in. Why I had trouble with it was that…which is typical of standard guitar…I had a single output lead from the selector to the volume pot. That meant that in the centre position the selector was connecting the neck pickup back in…anyway…I'll draw up a diagram in due course… So what went wrong…every possible thing imaginable...from a faulty "scratchy" pot on the amplifier to two broken tracks on the circuit, battery leads breaking, LED shorting on the signal lead (that's not good, sounds so bad…) and the battery leads snapped off about 5 times and a dodgy output jack (even though it's a new replacement "quality" one! If I'd had any hair left, I'd have pulled it out….aghhhh… So why all these problems…cause the sustainer circuit, battery, etc was hanging out of the back of the guitar by it's output leads and got pulled around and damaged every time I pulled the scratchplate off (I didn't want to drill holes for the switches and pot till I knew it was going to work now did I…Let that be a lesson for us all…hopefully I'll be able to draw up an installation diagram to save you the grief… OK…so why is it only 80% successful…this is where I really will need some help… #1…(I think LK knows the answer to this one)…there's a major pop when the sustainer's turned on!! I'm sure there's a simple solution that I've been told before…something about a resistor or something?? #2…there is some major interferance going on…some of it may be the proximity of the driver leads to the general signal carrying wiring…I may need to reroute the driver wires away from most of the circuitry through the trem cavity… I don't know that is the only solution that will be required…even though the neck pickup is inactive, the phase of the pickup (I've got phase switching on this pickup) matters. When the driver phase is reversed, so too must the this pickup's phase…weird… #3…The driver has moved due to my adding of an earth wire so that the driver blade only just sits under the high E…also the action of the guitar needs to be adjusted so that I can get the high strings closer to the driver all the way along the fretboard. #4…The sustainer seems to work better in it's proper position and it seems I may be sending a little too much power into it at higher settings creating a buzz-saw type of distortion (interesting special effect but not really useful)...so perhaps I need to lower the preamp gain a little (bodes well for the fetzer/ruby circuit though). #5…as I need to send more power to get those high strings singing, I might have to play with the output capacitor to lessen the bass response… #6…The system seems to like a bit of the treble rolled off with the tone control…in fact the buzz-saw sound disappears and you get a nice kind of tubular type of sound…even on really high harmonics…It may be that a roll of cap/resistor is in order on the bridge pickup when the sustainer is engaged to take the edge off it permanently… So all in all…after a lot of cursing…the thing is…well…in the guitar…and sustaining…but still needs some work… Anyone care to offer suggestions to these problems…feel free… psw Oh...and...on my pickup grounding...I'm now not sure...it appears that I've shorted some of the driver coil to the blade (even though I'd wrapped it in tape)...I could see where and super glue seeped in to repair the insulation a little...generally I don't ground the pickup poles at all so I was a little surprised that I'd need to...then it turned out that I needed to cut the ground wire anyway...so...hmmmmm Fray a wire and glue it to the underside of the steel with conductive epoxy... That stuffs expensive and I don't have any...I was able to solder a thin wire a little and used superglue to reinforce the join...then taped the magnet on it tightly to make an effective connection...shame it looks like the jury's out on wether it's necessary anyway...hmmmm Thanks anyway...got any thoughts if the core needs to be grounded...or my popping or interferance problems...the driver wires are just a thin multistrand pair (untwisted)...maybe they need a bit of a twist as is specified in the sustainiac instructions... cheers pete Link to comment Share on other sites More sharing options...
psw Posted June 24, 2005 Author Report Share Posted June 24, 2005 Here's a quote from another topic... ...Having all the grounds meet at one spot is just a good way to make sure you have all the grounds done right..It also completely eliminates the chance for noisy ground loops, which are really easy to wire in if you don't have a clear-cut idea of how your grounding scheme works. It's not compulsory, but it is cheap insurance. ← Link to comment Share on other sites More sharing options...
psw Posted June 25, 2005 Author Report Share Posted June 25, 2005 Playing around with the sustainer a bit...it's so much more fun in a guitar by the way...with the tone control wound right back and the right phase combination, the fundumental mode works perfectly...and by that I mean all strings, including the high E (even with the driver misalignment)...you do get the sound of the tone rolled off at the output though (which on this guitar is not a bad sound) but not ideal...The volume knobs a bit scratchy too... Thinking about it...as the bridge pickup is wired to the volume and tone and wired to the sustainer circuit...the volume and tone are also wired in to the circuit too...so the improved performance may be as a result of the rolled off highs going into the circuit as much as the rolling off the highs manifest in the guitar's output... There's surely quite a bit of complexity here...how would I roll of the highs on the circuit without effecting the output...post pre-amp (where the sustainers gain control is)??? Why the selection of a pickup only connected on one side of the coil should make any difference is beyond me I'm afraid...the fact that this stops when the connection to ground is reversed is what has led me to question the ground loop theory...perhaps the installation does require a 3PDT switch to disconnect both sides of the pickup coil to completely isolate it...but you'd think with only one end connected it wouldn't be able to allow current to flow...would you.... It's all a little odd...but so much fun when it works.... psw Link to comment Share on other sites More sharing options...
psw Posted June 25, 2005 Author Report Share Posted June 25, 2005 I was just reading about the so called "Zobel Network" in the instructions from my generic LM386 Kit circuit (Silicon Chip, Feb'94 CHAmp)... A Zobel Network consisting of a 0.1uF capacitor and 10 ohm 0.25W resistor prevent high-frequency oscillation from occuring due to long speker leads Link to comment Share on other sites More sharing options...
psw Posted June 27, 2005 Author Report Share Posted June 27, 2005 Enough bitching about the little quirky problems for now...here's the installation so far on the test strat... Here's the overall guitar.... Here's the back circuit cavity.... Here's a view of the controls and blue Led indicator light... The cavity is much larger than it needs to be...in fact you dont need to route a cavity on a strat as you could probably make room under the scratchplate... The top knob is the sustainer's sensitivity control...the switch closer to the bridge is sustainer on the other the harmonic switch On the back shot you can see I've twisted the blue/green driver wires and brought them through the trem cavity...it seems to have improved things a little... I've also added a trimpot jerry rigged filter on the preamp input which has helped to cut that noise...still getting a pop on switching and also the bridge pickup series parralel switching when the sustainer is on. I'm still getting "effects" from unconnected circuits...some of them good...some ok but it works better with different combinations of switching particularly in the harmonic mode... When it's set right it really works well. The high string response is very good now although the low strings respond best. Whith harmonic mode on the high strings you're into dog whistle territory just about.... String damping, especially on the lower strings is a must and there are all sorts of tricks you can do with the trem arm to initiate vibrations by scooping into the note...not to mention divebombs, sirens and horse neighs.... Anyway...the things in there now and is happily sustaining away even if it does need a little fine tuning... The next project will be to add a piezo output (the purpose of the other knob)...I've got a few preamps here so it shouldn't take long...not quite sure how I'll use it...perhaps just an on off switch and a volume control to blend it in with whatever pickups are in use to give it a percussive edge...so it's not really an imitation acoustic...open to suggestions.... Anyway...there she is...the pickup BTW sounds at least as good as it did (I actually think the addition of the blade has improved it) and the guitar functions in everyway the same as it did before...relatively high action and all... pete / psw Link to comment Share on other sites More sharing options...
Paul Marossy Posted June 27, 2005 Report Share Posted June 27, 2005 Lookin' good! Link to comment Share on other sites More sharing options...
Pekko Posted June 27, 2005 Report Share Posted June 27, 2005 Secondly...there seems to be a fault in Pekko's above switch scheme...when "bypassed-sustainer on" is selected and the selector selects both pickups (centre position)...the hot of both the neck and bridge pickups are effectively wired together meaning that the neck pickup is not in fact "bypassed"...at least when the centre, both on position is selected...given the cataclismic noise that results...this is a serious problem...hmmm... Psw, you seem to be right about the switching fault. Thanks for spotting it. Meanwhile, I've finished my second driver. This time it's a short coil with steel core, 0,2 mm wire and 6 rare earth magnets. First thing I noticed was that the magnetic pull was much less than with my previous driver using ceramic magnet. I tested it today with Fetzer / Ruby amp. Performance was much better than with my first version. This time I got infinite sustain easily with every string except high e. I also managed to get high e sustaining, but it's not that easy and consistent as the others. I had both N1 and N3 versions of LM386 around, so I tested both. I was little bit happier with N3, but the difference was not very big. My biggest concern is that the sustainer seems to distort my signal, which is going to amplifier. I suspect that this is caused by interference, I only connected the parts together with some test leads outside the guitar. Another problem is that I couldn't get harmonic mode working properly. All I could get was high frequency oscillation. I was able to change the frequency with my volume pot, so I did get some interesting sounds, unfortunately that was not what I was after. #6…The system seems to like a bit of the treble rolled off with the tone control… I had exactly the opposite results. Performance was much better without tone capacitor (I've left tone control out from this guitar, so I tested this with separate 22nF capacitor). I guess this depends on pickups, I have a dark sounding humbucker in bridge position and psw seems to be using single coil PU. Next I guess that I'll put everything inside the guitar and see if a proper installation helps with distortion problem. I might also add a Zobel Network to my amp to see if that helps with oscillation in harmonic mode. I also have material for some more drivers, so I might try one using magnet itself as a core. Regards Pekko Link to comment Share on other sites More sharing options...
psw Posted June 27, 2005 Author Report Share Posted June 27, 2005 (edited) Great stuff Pekko...I'll be looking forward to seeing how you go with the installation an all... Another problem is that I couldn't get harmonic mode working properly. All I could get was high frequency oscillation. I was able to change the frequency with my volume pot, so I did get some interesting sounds, unfortunately that was not what I was after. Edited June 27, 2005 by psw Link to comment Share on other sites More sharing options...
onelastgoodbye Posted June 27, 2005 Report Share Posted June 27, 2005 (edited) My biggest concern is that the sustainer seems to distort my signal, which is going to amplifier. I suspect that this is caused by interference, I only connected the parts together with some test leads outside the guitar. ← You seem to be experiencing the same thing I am: audible distortion coming through the signal, even on clean sounds. I always figured it was the driver amp leaking into the output signal somehow, presumably some faulty grounding. Though last time I tested the setup I actually used an fx send on my amp (you'd think that would be sufficiently isolated from the guitar's controls) to drive the input of the driver amp, and guess...same thing . And my emg isn't even grounded anyway, nor is my driver amp, so i'm starting to believe this is not really a hard-wired problem; but rather a shielding problem. The way I see it, the driver signal is actually induced into the pickup, then amplified to the main amp. I think we are underestimating the size of the m-field the driver puts out, heck I can hold the thing 1.5 ft away from the pickup and still make it squeel . So tomorrow I'll be taking up some of R.G. 's advice and have a go at shunts and the like. I actually built a new 8 ohm driver today, but f***ed it up (managed to break the magnet in half). I'm hoping it'll also facilitate driving the strings from underneath ( oddly enough still getting better results from above). More to come, Tim Edited June 27, 2005 by onelastgoodbye Link to comment Share on other sites More sharing options...
psw Posted June 27, 2005 Author Report Share Posted June 27, 2005 Tim I think we are underestimating the size of the m-field the driver puts out, heck I can hold the thing 1.5 ft away from the pickup and still make it squeel . Well I do too if I point it at the pickup from a distance...close by the strings the strings themselves act a little as a shunt...you must be getting similar effects but positioning the driver close to the strings must solve the problem or it wouldn't be working for you... I think the driver leads are important...they are after all, just an extention of the driver coil with the same EMI eminating from them (the pickup signal leads and controls are an extension of the pickup coil...designed to pickup EMI (string vibrations)). I'm no longer experiencing any squeel like feedback effects at all...just this high frequency noise which is kind of similar and, at the moment, still suspect the EMI from the driver leads... Sure a strange set of complex symptoms...effects from unconnected pickups ...but there probably is a solution and as I say, once you find a way to control them (filtering, phase, etc) the device works perfectly!! pete Link to comment Share on other sites More sharing options...
psw Posted June 28, 2005 Author Report Share Posted June 28, 2005 (edited) Hi...quick question...is connecting the +ve and -ve terminals together (short circuiting) a "safe" way to turn off and on a circuit...I'm imagining the battery might not like it... I ask because I may be able to work out a way to ground the othe non used pickups and maybe even drain the circuit caps (to address the pop problem) if that's the case... Otherwise...have to come up with something else...any takers.... psw Oh...and a related question...when I upgraded the jack plug I installed a stereo switch jack...the switch contacts are connected when the plug is not inserted...in other words open (or NC) when the jack is in... Does this imply that the power should be shorted out to disconnect battery...as I've kinda asked above...or how is it supposed to be wired.... pete Edited June 28, 2005 by psw Link to comment Share on other sites More sharing options...
BDRockStar Posted June 28, 2005 Report Share Posted June 28, 2005 hm...really late in the game to be asking such a stupid question - but just for clarification - how do you hook the driver up to the rest of the circuit? Link to comment Share on other sites More sharing options...
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