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Post by cynical1 on Nov 6, 2011 21:51:35 GMT -5
NOTE: The diagrams change several times during this post as the passive bypass idea evolves. Please go to the end of this thread for the latest revision.Well, since the finishes are curing on Project #2 I found myself going through a bit of tinkering withdrawal... So I figured I'd drag out the Fernandes project. One of the things that bothers me about the Fernandes Sustainer is that you have to have a battery in place to get anything out of the guitar. Doesn't matter if the Sustainer is engaged or not, no battery, no noise. So I came up with this as a starting point:  The original Fernandes had single coils in the middle and bridge positions. I plan on replacing those with two Wilde L-90s. While this drawing doesn't show it, everything will be Star Grounded...just didn't want to put any more squiggly lines in then I already had... If I have this right, down puts everything as normal, requiring the circuit to be powered in order to get anything out of it. In the up position it reverts to a standard two humbucker guitar that doesn't know or care that there's a Sustainer in the circuit. I also tossed the obligatory Woman Tone Mod in there, but that's not what has me wondering. Assuming the wiring is correct for the bypass, which you guys will tell me if it isn't, do I also need to make the 9v power switchable? I intend on phantom powering the Sustainer from outside of the guitar, so I'm not concerned about battery life, as much as being able to use the guitar in a passive mode. If anyone spots something I've hosed up here, as always, please feel free to shout it out. Happy Trails Cynical One
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Post by sumgai on Nov 7, 2011 2:10:17 GMT -5
c1, Rube Goldberg ain' got nuttin' on you!  ;D So the Driver is also a pickup, is that right? And if so, then are you planning on spacing out the pups in the usual 3-pickup arrangement.... or is your drawing somewhat accurate in that one of the L90's will be crowding in close proximity to the driver/alleged pickup? Depending on your answers, I've got one or two alternative proposals to submit for your consideration.  sumgai |
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Post by 4real on Nov 7, 2011 3:15:09 GMT -5
Hard to verify the idea, looks well thught out and a good idea. The 'needs power' always bothered me and is a feature of my guitar/diy sustainer design. One reason is that they sustainer chews through batteries very fast, it is not a 'preamp' but a power-amp and there is no really way around it and performance suffers as the battery drains. By designing a system that is passive only when the sustainer is in use is a significant difference and saves a lot of power and no possibility of being caught out and a worthy thing to pursue. You may find some clicks or pops though switching from active to passive mode. It is hard to know exactly how things are going to work, so I would and advise building everything outside the guitar for testing and troubleshooting before a full install or committing to drilling holes in the guitar. Seems on first look to be a sound scheme and following the wires seems to check out. The complexity of sustainer wiring is evident here even without your added mods. I think mine worked out a bit simpler, but I was never sure when I contemplated a commercial version that people would be able to install the device correctly. I've played a 'sustainiac' and both them and fernandes were originally the same...that guitar worked great...but there are other issues that I tried to address with small drivers, passive off operation and that kind of thing... Good luck, will be looking with interest |
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Post by cynical1 on Nov 7, 2011 8:26:54 GMT -5
Rube Goldberg ain' got nuttin' on you! ;D Oddly enough, I take that as a compliment. And it's a much better opening response then "WTF were you thinking?" Yes. The neck single coil pickup is also an active pickup without the Sustainer engaged. Once the Sustainer kicks in the neck pickup drives the strings and the bridge pickup retrieves the sustained string vibrations. Like this: www.fernandesguitars.com/images/stories/sustainer/circuito-sustainer.gif Fernandes USA went belly up. They took the image with them.The drawing is accurate in pickup placement. The driver neck pickup will be right up next to the alleged middle pickup. I did this for good reason. When the sustainer is engaged only the neck and bridge pickup do anything. The middle pickup drops out of the circuit and is just there for looks. If the passive mode works then the closer I can get the "middle" pickup to a neck position the better the two L-90's will sound and work together. So, the original Sustainer Driver\Active neck pickup and the "middle" L-90 will function apart from each other and only when their respective "modes" are selected. By this I mean that If I'm running the sustainer then the "middle" L-90 drops out, along with the 5 way and 3 way switches. When the sustainer is off then it's all the way off and only the passive output from the two L-90s will be used along with the three way switch. And from what I hear the Neck Sustainer Driver\Active pickup doesn't sound all that great anyways...so why not just use it for what it does best and put it to sleep the rest of the time. Granted, it won't do that automatically now, and will require user participation to make that happen, but this is how I would use the guitar in the real world. As it stands now, with the Sustainer board in the circuit the 5-Way would function just like a standard 5-way. In the current design, Fernandes has hard soldered the switches to the circuit board, so unless I want to de-solder them and rig accordingly this is the easiest way to go to keep from hosing the thing up completely, or having to figure out how to mount it without the toggles attached. So the tally as it stands now is two toggles for the Sustainer circuit board, two S\P toggles, one over-ride toggle, one 3-Way toggle and the original 5-Way switch. Along with the master volume, master tone and sustainer intensity pot...that's a lot of holes for one pickguard... I hope to simplify this down the road, but for now I just want to prove the concept. It's all an experiment anyway and I doubt this is that last iteration of this thing. Ahhh...that's when the "WTF were you thinking" comes out... Happy Trails Cynical One |
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Post by sumgai on Nov 7, 2011 21:21:31 GMT -5
c1, Ahhh...that's when the "WTF were you thinking" comes out... I now have another question, but I think I'll just toss this out there and see who gets taken out by the fragments.....  Why not just use the sustainer board to drive the pickup only - forget the 5-way switch, etc.? Use the pictured LP-style 3-way selector to select which L-90, and then install another one just like it to select between the sustainer, the L-90's or both.....  Obviously, that second switch would not take care of the power problem noted by 4real, but it illustrates my intended concept. (insert noises here that approximate cogitation of the highest order......) Now that we've cemented that in our minds, we can go back and replace the second LP-style switch with a Tele-style 3-way switch, where one pole can control the power to the sustainer, not to mention we're also filling an already-existing slot in the body. A capacitor in the correct spot to soak up any "clicks", if needed and..... Voila!, mission accomplished. ;D....... Oh, did I mention that our buddy Rube would look down his nose at this in disdain, knowing that we have indeed embodied the KISS principle in full?  sumgai |
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Post by cynical1 on Nov 7, 2011 23:36:10 GMT -5
Why not just use the sustainer board to drive the pickup only - forget the 5-way switch, etc.? Use the pictured LP-style 3-way selector to select which L-90, and then install another one just like it to select between the sustainer, the L-90's or both..... You have stabbed right at the heart of what my primary intentions are. The only thing the Sustainer does is drive with the neck driver\pickup, and capture the output from the bridge pickup and run it through the board to do its voodoo. And that's all I want it to do. And it does it very well. I got the Sustainer to work for a short while before I took the guitar apart to work on the neck and route the body a bit more. After two batteries in as many weeks I knew I'd have to find a way to use it in a passive mode, as well as power this beast from outside of the guitar to make it workable. So, lets dump the 5-way...I never liked those imported switches anyways... This simplifies things as then the Middle\Surrogate Neck pickup just goes directly to the passive LP 3-Way and never sees the Sustainer board. I would assume that even if the passive 3 way and the Sustainer output goes to the same lug on the volume pot the sustainer output would bury the passive output. Or do I need to rethink this idea? If not, then no connections at CN6 on the board. At CN1 only pins 3 and 4 have an input from the bridge pickup. CN5 remains the same, as does CN2 What I do know about this board is that the bridge pickup has to feed the Hot and NHot into the board. This is about all I know for sure. That could also be done with a DPDT On-On switch right after the Series\Parallel switch. That takes care of the bridge input to the Sustainer board. As I see it, when the Sustainer is engaged the only thing listening to the strings is the bridge pickup. Having removed the 5-Way as drawn, I still would need to retrieve the bridge output and the Sustainer output from CN3, pins 3 and 2 from the board. I know what they are because they marked it... I'm a little lost here as I have two different outputs that I need to feed to the volume pot. Not sure how the board feels about it either... And as far as killing the power to the board, let's put the original 4PDT switch back in place. The right side still routes the bridge pickup as before...and since the left side of the 4PDT switch is now vacant, as the middle pickup is just routed directly to the passive 3-Way, why not route the Red+ and Black- of the power leads thought that side in place of the previous middle\neck passive pickup? As I see it, this way when the bridge pickup is fed to the Sustainer board it also gets power into CN4 pin 1. When the bridge pickup goes to the passive 3-Way switch it has no power fed to it, thereby taking the power feed out of the circuit to the board. Or does running a signal and 9v power through the same switch create its own set of problems? The Sustainer board itself has a power on\off switch. Along with the strategically placed cap this should make all switching back and forth clickfree. I'm gonna have to look at the Tele switch idea a bit more. I'm a little stumped at how to drop that in place at the moment. Maybe I missed something along the way...or maybe the NyQuil and Robitussin are just starting to kick in... I'm not married to one switch over another as the existing pickguard is a write off anyway. The simpler and more intuitive I can make this the better...because more stuff will get humped in here eventually anyway...but that'll be a separate output anyway... Thanks, SG. If I understand your point that simplifies this thing immeasurably. Now, tell me what I missed... Happy Trails Cynical One Well, you've only seen about the 3rd or 4th revision...The first one had a parrot, a roman candle and a blowtorch in it... |
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Post by 4real on Nov 8, 2011 1:05:24 GMT -5
What I've found with my sustainers is that the on/power/bypass switch can get a bit convoluted...something like this is usually required for my systems with multiple pickups...  In later times if not shown here, I have just bypassed the selector and all pups, then reconnected the bridge and the power to turn it on... However, the commercial sustainers are quite different, they may well have electronic switching to cope with all these things adn not like the power going off...causing clicks and pops and such from various things. For instance, the driver stores a charge that is released often when power is off, there is a common power and ground rail going into the amp which can cause such noises. As you have found, these things do tackle quite a bit of power and will soak up all that is given, this could be a danger when powering externally and especially if trying to run the power source alongside the amp signal say in a stereo lead...although running of DC there can be quite sizeable momentary AC signals (and interferance) occurring when the power demands are applied, change or turned off to consider. In my designs, the battery is an integral part of the circuit, operating as a natural limiter, and aspect that many overlook. In units like the sustainer though there is quite a bit of signal limiting built into the circuit so not sure if that applies. I'm not sure if all this helps, but I would definitely be testing ideas out of the guitar as much as possible before committing too much to a particular scheme. The sustainiac and fernades units do give a great performance, but I always felt there were a lot of niggles to the design...the always on with a huge power consumption that threatens to kill the guitar when the battery dies is a big thing but that design aspect may well be there for a reason and it would be best to test any ideas to see if they are at all practical before committing to them, I'd encourage. The only commercial unit I have had my hands on btw was a sustainiac in a custom made jem like guitar. It included a 'mix' control knob that I suspect was some kind of filter and you don't see often. It was very effective though for dialling in harmonics and the like though...a bit similar to what the moog guitars offer in an outside pedal... Otherwise, you have identified a lot of the 'niggles' of them and the complexity of installation and possible solutions. However, the companies also know these things and yet have not addressed them...there may well be that this is because these things are an essential element to their design and significant problems might exist to try and work around them...at least in a performance mode. As with all things sustainers, make no assumptions and test everything! Even a well thought out commercial product can be a real frustrating trial to install...but how much fun are they...two batteries in two weeks...how many hours is that of playing? (btw...I am helping a guy at the moment who is a professional editor and is doing a nice PDF from our conversations and his own build experiences as we go, so hopefully in the future there will be something a bit more concise to offer for the basic DIY devices if people are interested in building their own that does not use power when not in use and the guitar work passively without it at all times) |
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Post by gumbo on Nov 8, 2011 4:57:00 GMT -5
C1... ..are you sure that wasn't a wiring diagram for an automatic washing machine? |
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Post by cynical1 on Nov 8, 2011 9:44:50 GMT -5
What I've found with my sustainers is that the on/power/bypass switch can get a bit convoluted...something like this is usually required for my systems with multiple pickups... Have you got a bigger image of that? The power in to this guitar will be on a separate plug and jack arrangement from the 1/4" stereo jack. Something along the lines of this:  It'll be carrying other stuff, but it'll be this type if industrial heavy duty arrangement. Makes sense. Fernandes is very heavy on the marketing information freely available, but there isn't much published on the nuts and bolts. I can only guess that this thing must be pulling an amp or better at 9v to eat batteries the way it does. Once I can get a firm number on power requirements then I can build the external power supply accordingly. Once I get something that looks doable I'm going to fire it off to Fernandes and see what they come back with. For all I know the board may not function unless all expected devices are connected and functional. They did say the series\parallel switches ahead of the board would work. It will, of course, change the performance of the sustainer, but I'm willing to try it to see if I might like it. Companies are normally aware of many of the shortcomings of their products and designs. Until it effects sales it is rarely addressed, and even then there has to be a return on the redesign to make it a reality. I think Fernandes and Sustainiac have their niche, everyone who uses it knows it's drawbacks, but is willing to accept the trade off to gain the benefits. Well, when I first picked up the guitar I was burning an hour or two a night and probably 8 hours on the weekends. This was when my mom was in the hospital and I was spending a lot of time back in Chicago with nothing else to do. That, and the fact that if you leave the damn thing plugged in it continues to eat your battery... If it was just for my personal use I'd be willing to tackle building one. I have bigger plans for this guitar, and having a name like Fernandes on the outside does more for marketing then one for a device which may be light years better. I'm going to have to piggy back off of their marketing budget. Happy Trails Cynical One |
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Post by 4real on Nov 8, 2011 14:57:02 GMT -5
All sounds good, and for that much playing with the thing, that power consumption is not at all bad considering...I believe they use class D amps like sustainiac and have done all they can other than a passive over ride to save energy. If you have a separate power, such as a Variax offers (also going to chew through power) it might not matter how much power it goes through. Unfortunately, rechargables don't tend to work too well, not lasting too long...for a while I was using a par of 9v and swapping them out but they could not take that kind of drain. That is a very nice looking plug socket there...hmmm..not seen one of those before... The intent is good though and anything sustainer really is kind of addictive, especially when you first get your hands on the things I must admit...looks like it is going to be one unique guitar, maybe there is a wave of 'out of the box' innovative instruments coming to the fore these days  |
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Post by cynical1 on Nov 8, 2011 16:32:36 GMT -5
The intent is to tie the power to the guitar, along with the signal(s) returning from the guitar into one interface. A Magic Box. It's baby steps for now as I try and get my head around what needs to be done, what can be streamlined and what parts need to be sourced.
The plug\receptacle pictured above is an example. Another example of my tendency to over-engineer everything. I want this guitar to be able to go anywhere, anytime and not cause the player any headaches or downtime. It's gotta be as tough as any professional tool a journeyman would rely on to make a living.
The jack\receptacle will handle power, piezo saddle or hexaphonic output. Not sure which way that's gonna go. I need to sort out the Sustainer circuitry first and get the blessing from Fernandes before I move along to the next step. Don't worry, I'll be back with that part down the road.
I'm going to take another shot at the diagram tonight and see if I can simplify this thing down as SG suggests. Handling the signal out of the board for the Sustainer and the bridge through the sustainer board still has me guessing. I'd like to fore go another switch if possible.
And I find your jazz guitar a very interesting project. LMII has closeout templates for an archtop, 1956 D’angelico New Yorker with a cutaway for $33.95 US and since you started your little soiree I'm thinking...hmmmm...
Happy Trails
Cynical One
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Post by 4real on Nov 8, 2011 17:45:47 GMT -5
Thanks C1.... I plugged my project's piezo in and got carried away fro an hour and a half playing...that's when you know you gt a 'good guitar'...but it is done on the cheap, the whole body cost about $39.95 LOL... My concern though with running the sustainer off remote power along side signal leads is that it is drawing a lot of current and if you go to passive you might get an almighty 'thump'. The sustainer circuits are all power amps and quite different from the kind of pre-amps and effects that draw little power and happily run from remote power like that, of for ages on a battery. But, the design criteria while difficult is what one should be aiming for and I am sure there will be solutions. I seemed to happen across a few but after being burn't a few times and seen others burned frequently with this device and call me to dig them out, I am extremely wary of committing oneself to a particular scheme until things are tested out fairly completely. I have not used it in a while, but when I did that "goblin" guitar  I bought a cheap strat and made it my 'test bed' guitar for this kind of thing...  That way I could replicate the scheme on a guitar remotely, move pickups about and get into everything working and know it works before it leaves me or goes into a host guitar...or to just test and tweak the kinds of things that we all love here. ... throwing evrything into one guitar can be a danger, but if you have a musical vison and work towards a practial solution to implementing things, I am starting to swing back to the 'swiss army knife' approach and evident in my latest project, but anything like that is going to have some significant problems to overcome, compromises to make and sudden changes in direction. Already I've had a few in this project and if I were to do it again (an I just might) there could be quite a few changes and deletions that i'd be making. If you have a musical vision though, if you keep plugging away at it, you will get there, or at least somewhere...and potentially further than you imagined with the end result...top marks for taking the road less travelled! |
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Post by 4real on Nov 8, 2011 20:26:24 GMT -5
What I've found with my sustainers is that the on/power/bypass switch can get a bit convoluted...something like this is usually required for my systems with multiple pickups... Have you got a bigger image of that? I kind of missed that, the switch thing evolved and that old one is from the original 'sustainer strat' and a little outdated...this is more the kind of thing in my tele and might give you some ideas for bypassing and power and such...  Another for a three pup guitar  nope...will keep looking for the tele, though the above might be useful...rather than go to each pup separately, eventually I just used the first two switch pairs to take out the entire selector and use the power ground and bridge ground to reconnect the bridge pup alone and turn on the power and so too the sustainer. So, bypass/bridge on/power on in one switch. It is a cool thing, as when you turn it off, it reverts to what ever the selector is or was at before activated...and of course entirely passive. I had one that also did the same thing on a position of a superswitch (which is 4pdt) and I dare say one might even manage to do something with the harmonics in such a switch to if so inclined. hmmm....  I am not sure where this one came from, it might well be someone else's based on my instruction but I've not revisited it...or I changed graphic style or something LOL. Have not checked it...hmmm Basically though, it shows a pickup scheme similar to yours and the switch more like the things I do these days, cutting out the entire selector...this is the approach I generally use as in my tele on my designs... But then, my idea for a sustainer is quite different from that of the commercial units and a different approach...much like you are aiming for, but built into the design itself. The aims or 'criteria' I worked from was fairly extensive and lot in the huge thread, but still remained true. One thing was to be an addition to a passive guitar with low mods to the instrument and no compromises as far as possible in that. So, own choice of pickups, combining the pickup and driver, surface mounted mini drivers, power only in sustain mode and all that was very high on the list. I developed a bunch of ways to achieve this, somethings were a bit 'sci-fi' and failed to eventuate. Looking through the photobucket archives for this switch I found this realization by a talented collaborator and graphic artist from years ago...  This used one of my 'hex' sustainers, the technology of which is what is being used in my new hex pickup project.  Ah...here, this looks like the tele switch and better shows the way things operate perhaps and generally applies to most guitars for my device...also shows the entire install there. I switched to this approach for everything...so lucky I found it again! ... I don't think it will necessary help, but the fernandes patent is fairly extensive and I think includes the circuit diagram over several pages. Far more convoluted in style than any of my posts or even threads I must say...perhaps I spent too much time in the USPTO ... The sustainer does draw quite a bit of power and the demands go up and down with the use as well as off an on. The interference is often from "back EMI" from current in the coil and I think the commercial units got around some of this with some tricky electronic switching that had a slight delay to drain the coil. Normal power smoothing strategies tend not to be enough as the DC signal can have AC spikes in it and if running along side signal leads you can get various noises. These are particularly apparent from the driver leads, so best to twist them and keep them away from internal signal leads to as far as you can. As an extension of the driver coil, they will also be putting out some of the signal from the circuit that is supposed to be driving the strings. These kinds of inductive things (sometimes called 'fizz') is something of a bane and even if 'de-selected' nearby coils will pickup the signals like a transformer coil pair and exit into the guitar amp. Hence in my designs at least, all other pickups and such need to be completely taken out of the 'loop' both hot and ground...hence the need for such switching. ... How much of this applies to or is transferable to the fernandes or similar is unknown of course, but within might give you some ideas or approaches to solving problems or avoiding them along the way. |
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Post by cynical1 on Nov 8, 2011 23:59:11 GMT -5
Thanks for sharing all of this information 4 real. While the only sustainer I have even a vague understanding of is the Fernandes sustainer, I don't feel like the Lone Ranger anymore. OK, for better or worse, I ripped out the 5-way and left only the Les Paul 3-way in place. I also modified the 9v power routing.  The more I thought about it I figured I should take the middle\surrogate neck pickup out of the loop when the Sustainer is engaged. I ran the NHot to ground and the Hot to one of the 4 poles on the 4PDT switch. I also used the last set on the left to handle the 9v+ into the sustainer board. I didn't bother with caps or any anti-click devices as I just wanted to get the idea down before the Nyquil put me out. From what I'm relatively sure about, this allows the guitar to act like a typical 2 humbucker guitar in passive mode, with the advantage of a series\parallel option for the two humbuckers. As is, it leaves the sustainer board unpowered and out of the circuit in passive mode. In active mode the Les Paul 3-way has no Hot input, and if I understand this correctly, effectively takes it out of the loop. Only the bridge pickup runs into the sustainer board, so only the bridge pickup has an output leaving the sustainer board. The only other output from the board is the actual sustainer output...which we've gone into before, so I'll leave it at that. However, this is where I'm a little stumped at the moment. In the original design with the 5-way the bridge routed to the right side typical bridge position of the import switch and the sustainer output routed to the right side common. So, once the sustainer was engaged the 5-way switch became academic. What I'm not certain about is whether the sustainer output and the bridge output can both be routed to the master volume pot on the same lug. This puts the 3-way, the sustainer output and the bridge active through the board output all connecting to the same lug of the master volume. Maybe this is alright, maybe not...I'm going to fire something off to Fernandes and just see if this basic concept is feasible or if it's just the sound of one hand clapping.... Anyways, that's where it sits tonight. The cold medication is starting to kick in and I think I'd better stumble off for now. Happy Trails Cynical One |
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Post by cynical1 on Nov 10, 2011 20:55:58 GMT -5
UPDATE from Fernandes!
First off, I want to say that in all the years that I've dealt with Technical Service departments in different companies, and have plenty of good and bad experiences to back this up, I have to give 5 stars to Fernandes. They took the time to review my drawing, and even dropped by the board to check out this posting. They gave me technical insights and specs that a will make this idea a working reality. And special thanks to Andres at Fernandes for sticking with me through all of my endless questions. This guy deserves a raise just on that criteria.
That said, the Fernandes sustainer is powerable from an external source. The recommended rating is 9vDC at 300 mA. This puts it right inline with the standard output from my little stomp box power supply from an earlier post here.
The bypass for the passive and active will work as drawn. Taking the middle and neck pickups out of the input side of the board will not effect the sustainer output or functionality of the board.
I'm still a little gray and fuzzy on the output side, but I think I've just about got my head around it.
Once I have everything squared away I'll re-draw the diagram for posterity.
Happy Trails
Cynical One
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Post by ashcatlt on Nov 11, 2011 1:07:18 GMT -5
IIUC your diagram and description, there will be at least some instances where the "raw" bridge pickup is connected to the output of the buffer on the board? Even if the board is off and unpowered it probably presents a pretty low impedance, which will sit parallel to the V and T and the input of the first active stage outside the guitar.
We can't say for sure how badly this will suck until we know that Z...or hear it.
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Post by cynical1 on Nov 11, 2011 7:41:55 GMT -5
Even if the board is off and unpowered it probably presents a pretty low impedance, which will sit parallel to the V and T and the input of the first active stage outside the guitar. If you look at the second revision the bridge pickup only connects directly to the board when the board is powered up. Look at the 4PDT switch. And the output from the bridge when connected without the sustainer engaged is an unknown. It would be the same tone if the 5-way switch were still in place and the passive switching did not exist. I'm certain it will sound different from the passive tone, but I would hesitate to put it in the "suck" range just yet. They do sell a lot of these and I would think that would be bad for business. The bridge routed through the board, sans engaged sustainer, is only there to prevent a dead spot in the switching. As I said before, the outputs from the sustainer board are still a grey area. I'll update it once I have the blessing from Fernandes. HTC1 |
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Post by 4real on Nov 11, 2011 8:29:47 GMT -5
In my sustainer design, I have the circuit permanently wired to the bridge pickup and it would appear to have no effect at all on the sound with or without on multiple guitars to have it there powered.
My circuits are basic buffered input amps and likely will be similar in effect.
Not following the observation (being after midnight here) but are you saying the pup is after the buffer when un-powered, or before?
...
The main reason I see that they are active is to avoid on/off power pops and that their driver which is a very low impedance needs both a transformer (on the back of the board, at least in the old ones) and pre-amping to work as a neck pickup when not in sustainer mode.
I took a different approach to the things to make a compact driver or combine it within a normal passive pup and keep everything and choice of pup quite separate.
Sustainiacs are much the same, they used to make the fernandes units for them years back and there is some bad blood I believe. Still, sustainiac took the idea from Micheal Brooks's 'infinite guitar'...Floyd Rose also has a patent on one of course as does the original eBow...
But, when I did an exhaustive search on the devices, I found one that goes back to the late 1800's...for piano!
Nothing new under the sun after all.
It's hard to know how things are going to pan out and I imagine only testing and troubleshooting will determine things in the end.
...
For me a problem for a long time working passively was not in turning things on, but a click or pop tuning things off. As they improved they got better, my tele is completely silent but has a quirk, you are best to turn the thing off while actually making a sound on the guitar. The problem seems to come from the 'back EMI' or stored capacitance charge in the coil being released into the ground plane and this eliminates any trace (it is not simply masked) of a noise when turning things off and going passive.
This is also a reason why I needed a 4pdt switch to remove any other coils near by as they get charged or create distortions into the ground (and so the guitar amp) like a pair of transformer coils.
Unlike signal processors like pre-amps and effects, or normal pickups, these things are putting out quite a bit of electromagnetic energy and it tends to get in everywhere it can...especially since they are being run within close proximity of devices (pickups) that are extremely sensitive to picking up the magnetic disturbance of a string vibrating in a field...it's all something of a balancing act in the end.
...
There is a lot of unknowns in a lot of this and I suspect that fernandes techs wont know all the variations as they don't attempt to run passively.
It did not fit with my design criteria to do the obvious thing and just not turn off the power when in use to avoid such things or to add circuitry to create a little delay in the switching to hide the switching noise. Perhaps that is what is going on, or perhaps it is required purely to run the neck pickup.
Either way, the sustainer eats batteries (there's even more than mine I suspect) and you don't what your guitars performance to suffer from a low battery or to completely die. Besides, batteries start to add up after a while and rechargables done have the staying power.
Hence my criteria which was to keep things simple and the sustainer as an 'addition' to the guitar more than a 'sustainer guitar'...besides in generally it is a DIY project and I don't have the electronics chops, just the tenacity to make things till they do work...unless I give up of course!
Again, I'd be mocking up the entire system on a test guitar or rig before making commitments and see if there are problems and what the solutions might be.
It's a really interesting project though and all going well, will be an advancement in installation and function with the commercial systems I've not seen elsewhere.
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Post by ashcatlt on Nov 11, 2011 9:24:20 GMT -5
Actually, I was wrong. It's the output of the pickup selector that meets the "wrong end" of the sustainer board (at the volume pot) which would mean that the passive tone in general would likely suck.
That big ? wasn't on the diagram last night. Consider this at least a partial answer to that question. I'm not the least bit worried about the input to the sustainer board. It's likely high enough in-Z to where the loss of treble will be subtle. You will need to switch the output of that board off of the V pot when not in use, though.
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Post by 4real on Nov 11, 2011 15:04:39 GMT -5
Ah...well in that case Ash is probably right...perhaps you need more switching terminals to take that out too...well spotted
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Post by cynical1 on Nov 11, 2011 19:11:57 GMT -5
And that's exactly why there's a question mark at that very junction.
I'm still waiting on some specific information from Fernandes to hash out exactly how I need to handle that.
I was wondering, and its come up here before, would a Schottky diode on the Fernandes output be a potential candidate for separating the passive from the active?
Since a 4PDT is as large a toggle as I can find I'm sort of stuck at the moment using the LP 3-way... The Grayhill 6PDT rotary switches ChrisK talked about are all non-stock items and over $20.00\e. I went looking for a ganged toggle switch to completely isolate the passive and active elements, similar to the mechanically ganged panel circuit breakers, but came up dry. The existing 3-way switch may very well be replaced by a different switch configuration depending on what I hear back.
Everything is still on paper and up in the air. The concept is doable. The challenge for me now is to do it with a minimum of switches and no dead spots.
Happy Trails
Cynical One
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Post by sumgai on Nov 12, 2011 5:24:02 GMT -5
My only question is this: why must the Bridge pup be connected to the sustainer circuit at all? I mean, the eBow doesn't need this, so why does Fernandez, et al.? Seems to me that the if the pickup is a necessary part of the sustaining circuitry, then that circuit was designed improperly. All that coil can be doing is inserting some inductance value - it certainly isn't necessary for the actual job of exciting the strings (see reference to eBow, above). I seem to recall 4real asking for a circuit, a long time ago, that used only a stock Strat-style 5-way switch, and that turned the sustainer power on for only one position - the other four positions were passive-pickup(s) only. Should I trot that out for inspection here in this thread? I suppose another way to ask this question would be: Is there a law written down somewhere which requires that the Bridge pup is the only one that can be used to "receive" the sustainer-driven string vibrations? Can't this also be done with any other pickup that happens to be mounted to the axe? Life would be so much easier........ sumgai |
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Post by ashcatlt on Nov 12, 2011 10:28:59 GMT -5
There must be some pickup to feed the sustainer. You can see how this is true, no? Even the ebow has it's own little pickup inside of it.
The sustainer coil by it's very nature and purposely throws a whole lot of EM radiation out around it. This induced current into any other coil which is close enough to feel it. From what I've read you absolutely don't want to hear what this sounds like, and the bridge pickup is as close to a neck position mounted driver coil as one can get without that horrible noise. IIRC a large part of that huge thread on project guitar involved 4real and his friends trying to get around this.
So, it has to be the bridge pickup feeding the outside world when the sustainer is on. Could you use the middle pickup to feed the sustainer while listening to the bridge? Maybe, unless the EM "noise feedback" is loud enough to cause the desired string feedback to fail, or become unreliable. And I don't really see how that simplifies this thing much.
A different question, though: Why do you ever need to hear the output of the sustainer board? It's just a buffered version of the bridge pickup. Seems it should be possible to override the toggle (like a solo switch which turns the bridge only on no matter what else is going on) and power up the sustainer in four poles or less. In fact, that sounds like a DPDT to me.
Edit- Oh, I guess I forgot for a moment that - aprez 4real - the other pickups need to be disconnected at both ends. Apparently if you leave the "ground end" connected they still inject that induced noise into the signal. So I guess it does need at least 3 poles.
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Post by cynical1 on Nov 12, 2011 12:08:57 GMT -5
My only question is this: why must the Bridge pup be connected to the sustainer circuit at all? I mean, the eBow doesn't need this, so why does Fernandez, et al.? When the sustainer is engaged the neck driver excites the strings. The bridge pickup is employed to capture said vibrating string. When engaged only the neck pickup\driver and bridge pickup are selected for output. The middle pickup and any resident switching outside of the board are dropped out of the circuit and non-functional. For reference, and since I scribbled all over the original, this is the Fernandes installation drawing:  Right or wrong this is the tool I have to work with. While the idea of making a "driver only" and placing it into the guitar would make things infinitely simpler, Fernandes has a name and reputation out there and people know it. This is just a trade off I need to accept. Marketing is. And if I wasn't trying to re-invent the wheel by asking it to do what it was never intended to do by going into a passive mode I wouldn't be scratching my head right now... As stated above, the bridge pickup "reads" the vibrating string the the "driver/neck" pickup excites. With the sustainer engaged that's all it does. The reason I want to keep the bridge only non-sustained pickup in the "loop" with the sustainer board in the circuit, but sustainer driver off, is to keep the guitar from just going dead. This way if the board is in the circuit, but the sustainer switch is off, at least the bridge pickup will output a non-sustained signal through the board. I've watched enough videos of players using the Fernandes unit to see that many use the sustainer intermittently during their playing, especially solos, and asking them to make multiple switching routines during the course of their playing would be a significant drawback in functionality. The only other post I found here regarding "sustainer wiring" on a commercial unit was help with some series/parallel/sustainer wiring. But that was for a Sustainiac. It still routes the bridge pickup directly into the board. This layout had only two pickups and no 3-way or 5-way switching, just toggles. I've studied 4Real's diagrams and the they would work perfectly, aside from the fact that Fernandes requires BOTH the Hot and Nhot from the bridge pickup to be routed to the sustainer board. This burns an extra pole on a 4PDT switch I could use for final signal routing. I've been looking for a 6PDT or 8PDT rotary 2 position switch that doesn't cost your left leg...but most are a non-stock special order items. I did find this one, 8 POLE 3 POSITION ROTARY SWITCH:   According to their nomenclature: Switch utilizes a 3/8" diameter solid D-shaft and can be mounted through material up to approx 3/16" thickness. Includes a black plastic knob with set screw.
Main body of switch is 1.5" (including solder tabs). Very low profile design needing only 1" of mounting depth.Just not sure what to do with it yet, or it would offer any real advantage in functionality... I've been looking at using a 5-way switch. I just need to figure out how to make it logical in use, and not leave a replicated or dead position. The quest continues... Not so much a law, but physics is physics. According to Fernandes, the "Sustainer driver requires a minimum distance of 2 inches from bridge pickup, this is due to magnetic properties of the system." They talk about how to bypass the board for a different neck pickup aside from their driver, but none of their posted technical support discusses bypassing it completely and going passive as an option. It would seem to me that that as long as you adhere to the 2" rule the receiving pickup choice is open, but I'm guessing that the bridge is the most effective position to place the receiver. Both Fernandes and Sustainiac design the bridge pickup as the receiver, so I'm willing to tag along... What were you thinking about doing? The whole thrust behind working this out is to add functionality without contributing additional complication to the switching. There's going to be trade offs in anything I do here. I know as Nutz we are willing to deal with additional switches and physical manipulations to get the tone we want. I'm not so sure that the average working musician wants to recreate an ICBM launch sequence to gain a particular tone... Thanks again to everyone for kicking in suggestions and pointing out the random land mines in the path. Happy Trails Cynical One |
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Post by ashcatlt on Nov 12, 2011 12:24:57 GMT -5
Okay, in case there's some confusion left over from my previous post:
The bridge pickup can probably just sit connected to the input of the board at all times. This will appear as an extra load, and damp a little bit of treble, but not a deal breaker.
So do that and leave it. When you turn on the sustainer (connect 9V+) on one pole you override the toggle on two more (disconnect B+ from the toggle, and swap the V pot input from toggle to bridge) and disconnect the neck/middle from ground on the fourth. Yes, if you want the bridge only for solos and want to turn the sustainer on and off in the meantime then you have to flip the toggle first. You'd do that anyway, even if you didn't have the sustainer, right?
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Post by cynical1 on Nov 12, 2011 12:37:58 GMT -5
The sustainer coil by it's very nature and purposely throws a whole lot of EM radiation out around it. This induced current into any other coil which is close enough to feel it. From what I've read you absolutely don't want to hear what this sounds like, and the bridge pickup is as close to a neck position mounted driver coil as one can get without that horrible noise. I've read the same things. Keeping the driver as far away from the bridge as physically possible seems to be a design consideration for both Fernandes and Sustainiac. I'm willing to maintain that theory...I'm screwing with the wheel enough as it is... I don't know exactly what board level processing is taking place on the Fernandes circuit board. I do know it takes the bridge receiver signal and with the sustainer driver engaged outputs it with either a natural or harmonic sustain, as well as adding in a sustainer intensity pot to tweak either toggled option. With the sustainer board in the circuit, but not in active sustain mode, it handles to output of the bridge pickup, more or less as a pass through. I don't want to create a situation where a player engages the sustainer driver, then just flips the sustainer on\off switch and has a dead guitar. The bridge pass through still needs to be there in the boards output until said player flips back to the passive bypass. As far as the power on\off to the sustainer circuit, the On\Off switch on the sustainer board is a 3PDT switch. I could desolder that switch, make it a 4PDT switch and in essence put the 9vDC 300 mA power on\off on that extra pole. The downside of that is board level soldering, disassembly, reassembly and working out a way to reinforce the sustainer board mounting as it uses the toggle switches to mount the board to the body. Then there's that whole "no dead or redundant" position criteria... There's probably a simple way to do this...if it wasn't so damn hard figuring it out... I think I need to list out the routes and functions and just think about it logically for a bit. Happy Trails Cynical One |
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Post by cynical1 on Nov 12, 2011 12:57:40 GMT -5
Okay, in case there's some confusion left over from my previous post: I got the last post...you sort of lost me on this one, though... I don't see how I would be able to gain a bridge selection in passive mode without switching the bridge output somewhere...but I probably missed something here... Let me stare at this for a bit. I think I get the gist of what you're saying here, but let me go feed some horses and see if the light bulb goes off. I'm still a bit vague on how I'm going to get the bridge in passive mode without splitting that output somewhere. Yes, you have to engage the 3PDT sustainer board toggle to turn the sustainer on and off. Happy Trails Cynical One |
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Post by ashcatlt on Nov 12, 2011 15:31:53 GMT -5
Well that helps me! The switch I was talking about would basically have replaced the sustainer's on/off switch altogether. It doesn't accommodate the harmonic mode, but a Bridge Phase switch would do the same thing and allow you to get N-B in passive mode. Did you already have a phase switch planned for this?
What I'm thinking is that the input to the sustainer board just sits across the bridge pickup in parallel. The bridge would have to also connect to the toggle and the new sustainer "power" switch which both turns on the sustainer circuit itself and bypasses the selector toggle. The actual pickup output will always be passive no matter what switch is flipped which way and there won't be any dead positions.
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Post by ashcatlt on Nov 12, 2011 15:45:02 GMT -5
Use 4real's diagram. It does what I've been trying to describe, and he's actually thought a while about how to make it happen. I'm pretty sure that moving his "mode" switch to the bridge pickup (before the other switches) makes it into a phase/harmonic mode switch as I described.
You'll need to figure out what to jumper in place of the Fernandez switch to have the board always on.
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Post by cynical1 on Nov 12, 2011 16:07:39 GMT -5
Ash -
I think we're at cross purposes here. The way I see the two modules, active and passive, each is their own separate entity. The only fly in the ointment as I see it is the damn bridge pickup.
By design the Fernandes board monopolizes it for its own use. It must see the Hot and NHot input. And since it now "owns" that signal, while the sustainer is engaged the only way that bridge pickup is talking t anything is through that board.
And since the sustainer has two outputs, IE Bridge and Sustainer, I need to accommodate both of those, without them seeing or being influenced by the passive side of things.
It seems I'm going to have to switch the active and passive elements to the volume pot to keep them apart. The trick now, as I see it, is how to switch the bridge back and forth, along with switching the 9vDC power.
It seems I need more poles to do this from a single switch then is commonly available on the market.
HTC1
EDIT: Sorry, forgot to answer you other question. At present I was not planning on employing any phase options. I've got enough trouble with what I've got here already...
EDIT#2: I probably should have mentioned this earlier, but the outputs from the sustainer board emit absolutely nothing if the board is unpowered. So trying to pull the bridge out from the board in passive mode is attempted it will emit no sound whatsoever. This is that part I'm trying to get around with this guitar, so it will work even if the sustainer board is inactive.
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;D
