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Post by newey on Nov 2, 2011 18:48:03 GMT -5
A while back, I started a thread in the coffee shop, just generally speculating about building a "Stealth Strat". The idea is an uncluttered look that emphasizes the classic lines of the Stratocaster, sort of an exercise in minimalism. Project Planning- Stealth StratNow that the project has moved along and is well underway, I thought it was time to start a thread dealing with the electronics of this project. Here's some photos of where I am, construction-wise. The game plan is a single piezo pickup mounted to the body, and a Lace Alumatone HB under the pickguard. 2 DPDT On-On-On toggles provide the switching.   JohnH has helped me with an onboard active preamp/buffer circuit. I drew up the schematic based on his initial drawings. This is a stripped-down version of his piezo/mag buffer circuit. The piezo gets a preamp imparting some gain, while the mag gets a zero-gain buffer circuit. The two sides are then blended together by a pot, in this case it is to be pre-set by a trimpot under the guard. Alternatively, I may mount the blend pot in the trem spring cavity and make it adjustable via a small hole in the backplate, through which a screw driver could be inserted. Either way, it will essentially be a preset ratio.  JohnH then cleaned up a stripboard layout, after several fairly messy attempts on my part. My challenge is now to solder this up:  The red wire on the upper right is 9V+, working down from there, the first green wire is the piezo +, second green wire is the mag +, black is ground. Red wire on the left side is the output. Note that the red squares on the stripboard represent cuts in the track. However, the one appearing under the one cap connection is erroneous, there is no track cut there. The one switch shown will select mag buffered/ piezo preamped/ both together. The second switch is still up in the air as to function, but my inclination is to make it dedicated to the mag pickup, so as to switch between active and passive mag operation, thus allowing the guitar to be used in the event of battery failure. The third position on this switch is still undecided, perhaps a hard-wired tone cap setting for the passive mode. Any and all thoughts are appreciated . . . |
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Post by JFrankParnell on Nov 3, 2011 10:37:55 GMT -5
Where'd you get the invisible strings?
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Post by newey on Nov 3, 2011 18:08:36 GMT -5
Same place Cyn gets his invisible picks . . . ;D
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Post by cynical1 on Nov 3, 2011 19:38:36 GMT -5
 ...saves a fortune on tuners and setups... HTC1 |
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Post by sumgai on Nov 5, 2011 0:01:40 GMT -5
Yeah, I used to play around with that AirAxe™ stuff, too.
I quit using all that though, after I got trounced in a competition last year. The whole show was over when the guy after me somersaulted off the top of his Air Amp!!
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Post by newey on Apr 10, 2012 16:48:04 GMT -5
Did some more work on this project over Easter weekend. And I'm posting a cautionary tale as a result. Earlier, I had noted that mounting the Lace Alumatone "low boy" HB was going to require adding some wood so as to have a surface to screw the pickup down onto. I did that, and mounted the pickup. That's all good, it comes to just under the guard as planned. I also put a wooden block over the piezo disc and screwed that down so the piezo is well and truly encased in wood. However, if one looks at the photos above, you'll see that I already drilled and mounted the pickguard for the two switches. I had positioned them to be tight up towards the bridge so as to be as "stealth" and unobtrusive as possible, and also to be close to my right hand for quick changes. Unfortunately, I should have waited to drill the pickguard. The mounting position of the HB interferes with one of the switches, it was fine before I mounted the pickup, but now the guard bulges upward because the switch body contacts the HB mounting. I can't reposition the HB since it will then not be centered under the strings. Plain and simple, the switch has to move down, just a few mm probably, but more than I can "fudge it". Which would leave me with a hole in the pickguard, which would be decidedly ugly. So, a new mint green pickguard (custom-made without any holes in it) is on its way from Warmoth, and I'm into the project for an extra $30 ($25 plus S&H).  Moral of the story for you builders out there: Do things in order, don't get ahead of yourself, and don't do things early on just to get a nice picture. . . |
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Post by sbgodofmetal on Apr 16, 2012 23:00:36 GMT -5
Glad to see this project coming along newey. ;D I've been waiting awhile to see it completed. So do you have any plans to do an off board volume/tone pedal like was discussed in the earlier thread between me and roadtonever???
I've got a schematic of my own design if your intersted.
Oh and before I forget, how do those alumitone hb's sound I've been looking into them but havent got to hear them myself yet!!!
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Post by newey on Apr 16, 2012 23:13:56 GMT -5
Well, I'll find out how the Alumitones sound once I get the guitar built!  I'm still debating whether to do a dedicated output to a "magic box" of some sort, but as this project moves along, my inclination has been to keep things as simple as possible. The current plan is that both the piezo and the HB get a simple buffer stage onboard the guitar, and then those signals are mixed into a single mono output. But that could also change . . . |
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Post by sbgodofmetal on Apr 16, 2012 23:29:15 GMT -5
Keep me informed on those alumitones some sound clips would be nice when you've completed the project. Can't wait to hear this guitar, keep up the good work newey.  |
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Post by reTrEaD on Apr 17, 2012 5:51:31 GMT -5
I'd be a little concerned about the distance the mag pickup will be from the strings. Normally, the pickups are protruding above the pickguard. In this case, the pickup will necessarily be below the pickguard.
Maybe some thought to putting the strings closer to the pickguard (or the pickguard closer to the strings) might be helpful?
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Post by newey on Apr 17, 2012 6:47:15 GMT -5
That is certainly a valid concern. I do have the pickup flush up underneath the guard, so it's as close as it can get. As to bringing the strings closer, that's a playability/set-up issue. I generally like my action a bit higher than the standard these days.
The prototype of the mid-'60s Fender Marauder used hidden pickups, but the model was killed when CBS took over. So, it's not a new idea.
My P-bass project uses a single coil Strat "rail" type pickup under the guard at the neck position, along with the regular P-bass split-coil style pup. The underguard pup is lower output than the P-bass pup, so when both are on the neck pup gets a bit swamped. If I were to redo the bass, I'd use separate volumes for the two pickups so as to be able to compensate.
There are some soundclips of the bass in Sounds Samples FWIW.
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Post by reTrEaD on Apr 17, 2012 14:09:50 GMT -5
As to bringing the strings closer, that's a playability/set-up issue. I generally like my action a bit higher than the standard these days. They are related, but one doesn't necessarily have to go directly with the other. Having a deeper neck pocket and/or thinner neck heel, coupled with a lower bridge will result in the same action. But it places the strings closer to the pickguard. Or you could have a "shim" that holds the pickguard closer to the strings. A 1/8" ~ 1/4" plate of ABS or plexy or whatever that has the same outline as the pickguard, but has large cutouts for the pickup and controls, etc. With the pickguard mounted on top of the plate, it's closer to the strings and the pickup right beneath the level of the pickguard can also be closer to the strings. Of course none of this will put the pickup as close to the strings as a "normal" arrangement. And at some point, there is a limit to how close the pickguard can get to the strings before the pickguard gets in the way of normal picking. But if you find the mag output too weak, some room for improvement is possible. |
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Post by newey on Apr 17, 2012 18:37:14 GMT -5
We'll see what the output is like. The idea of a pickguard mounting plate is interesting, but I think I'll see how it sounds first, and if it's unacceptably low in output, then I'll start looking at other possible solutions.
The active electronics will also allow me to adjust the relative mix between the mag and piezo pickups, so it may well be that there's really no problem.
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jaylow
Rookie Solder Flinger
Posts: 13
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Post by jaylow on Jun 7, 2012 2:28:29 GMT -5
I'm thinking of using this in an old project and I was hoping to ask a few questions.
What are the purposes of the three trimpots?
Are Q1 and Q2 a couple of 2N5457 transistors?
What kind of capacitors are used?
How is the balance between the magnetic pickups and the piezo?
Sorry if some of the questions are a little noobish. I have no problem soldering but I'm not very good at the theory behind the circuits. Thanks for the help everyone!
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Post by newey on Jun 7, 2012 5:45:31 GMT -5
Hey, jaylow, welcome back! This project, as with several others I have gathering dust, is awaiting my work schedule to settle down a bit, so that I have some time to proceed. I won't know that until it's all built and strung up. The buffer board has a trimpot to mix the 2 signals, and my current plan is to move that pot off the board and mount it behing the backplate, between the trem springs. I'm only using 2 springs and the battery already fits back there as well. The mix could then be adjusted without having to de-string, remove the pickguard, etc.- either by removing the backplate, or perhaps through a small hole to fit a screwdriver through the backplate. And, on mine, it's "mag pickup" singular, not plural. VR3 (as per the diagram, it's labeled as "R10" on the schematic) mixes the piezo and mag signals, as discussed above. VR1 and VR2 (R9 and R10 on the schematic) are used to set the gain on the piezo stage. Yes. They are all electrolytic caps, I don't know the materials in them but they are the ones that look like little metal cans. I'm still in the building stage on the board, as I said not enough time to follow through with it. Please let us know how your project proceeds.  |
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Post by sbgodofmetal on Jun 7, 2012 12:18:21 GMT -5
Hey newey this may be more effective for your piezo element.  windworld.com/products-page/electronic-hardware/piezo-cable-sold-by-the-inch/The cable itself is the piezo element. Enough to do a guitar only costs $12 and that price includes shipping. All you have to do is Solder it to the base of your bridge and the other end to where ever your connecting your pups to and voila!!! Instant acoustic electric sound. Enjoy!!! |
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Post by reTrEaD on Jun 7, 2012 17:29:08 GMT -5
All you have to do is Solder it to the base of your bridge and the other end to where ever your connecting your pups to and voila!!! Instant acoustic electric sound.
Enjoy!!! it to the bridge? Seriously? Have you actually done this yourself? Can you cite an example where this has been done? Or are you just extrapolating from a tiny bit of information you read and giving questionable advice? Piezo elements generate voltage by compression and release of the element. In the case where you have a large area (film or disc) the surface vibration can be enough to generate a useable signal. But the piezo "cable" has a relatively small surface area. It is intended to be sandwiched between the bridge and bridge saddle on an acoustic guitar. The saddle vibrations are coupled directly to the element. Soldering would make the outer braid rigid. This is likely to reduce the effectiveness of any vibrations on the element. I'm not saying there won't be some signal generated. But unless you've done this yourself (or can cite a reputable source who has done this), it's poor form to recommend it to others as "voila!!! Instant acoustic electric sound." |
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Post by 4real on Jun 7, 2012 20:02:42 GMT -5
I am really looking forward to hearing how this works out. In particular I'd be interested to know more about the lace pup and how it sounds as these have been of interest lately. They claim to be a current rather than voltage device but I'm not sure what that means, but I have heard some impressive sounds out of them.
Without taking sides, that is misinformation regarding that cable and really do you think that all these people will have been dealing with preamping and impedance matching and all that if mags and piezos at the very least have vastly different loading qualities? All the manufacturers of theese devices have some how missed that none of this matters. Myself, Newey and John and all the rest are just seeking to complicate things cause they want to put batteries in their guitars?
Reality says otherwise and while this is interesting, it is not quite what you think it is I can assure you. I do have several piezos of different types including flexible shielded piezo "wire" of this type for acoustic saddles and it is certainly not the case that you can just solder these things in and get 'instant acoustic sound' and certainly not be able to 'mix' such signals that you do get with mag pickups successfully.
There is often quite a bit of misjudgement I feel that some how the piezo transducer = acoustic. It if perfectly possible that magnetic pickups can produce quite reasonable super-clean broad range responses that have 'acoustic like' qualities. On of which is the lace sensor pickup in this guitar as it happens.
The sound on the ride out of this clip demonstrates that the alumitones can produce 'acoustic like' sounds of it's own without the piezo side effects...but there plety of other pickups emerging for soundhole applications and others too that have these qualities. Largely we think of the sound of mag pickups because of the way they are conventionally designed which have strong resonance peaks and very high impedances.
In this project, I suspect the combination of the two could well be something very interesting and useful, I'd love to see how it all works out.
There is a difference between asking questions and making very bold statements without absolute proof or references to back up such claims that would very much appear to be misleading and simply wrong. I support asking questions (I've certainly asked a few of my own), but that is not the way one learns, it is taking in and researching more the answers given and consolidating that information...preferably backed up with experiential experimentation. First, one needs to survey the field and get the background knowledge to understand what a lot of these sources are saying and meaning, not the product catalogues.
For instance, many of us have played with piezo elements and in earlier times thought naively enough that this kind of thing might be possible (just stick it int here, wire it up, viola!), but even the most basic experimentation shows this not to be the case. Wish it wasn't, perhaps there is some kind of new technology (i did see a bridge marketed that claimed not to require impedance matching and so effectively passive) but certainly not in the way described!
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Post by sbgodofmetal on Jun 7, 2012 20:36:06 GMT -5
All you have to do is Solder it to the base of your bridge and the other end to where ever your connecting your pups to and voila!!! Instant acoustic electric sound.
Enjoy!!! it to the bridge? Seriously? Have you actually done this yourself? Can you cite an example where this has been done? Or are you just extrapolating from a tiny bit of information you read and giving questionable advice? Piezo elements generate voltage by compression and release of the element. In the case where you have a large area (film or disc) the surface vibration can be enough to generate a useable signal. But the piezo "cable" has a relatively small surface area. It is intended to be sandwiched between the bridge and bridge saddle on an acoustic guitar. The saddle vibrations are coupled directly to the element. Soldering would make the outer braid rigid. This is likely to reduce the effectiveness of any vibrations on the element. I'm not saying there won't be some signal generated. But unless you've done this yourself (or can cite a reputable source who has done this), it's poor form to recommend it to others as "voila!!! Instant acoustic electric sound."Since you feel the need to instagate every single new post.... Answer.... yes you solder it there's a lead and a ngative wire in it plus metal sheilding around the cable itself, the piezo wire does remain unsoldered while the ground is soldered to the bridge and the lead to output jack, volume pot, or selector switch!!! Happy to explain it further Hope it helped P.S. they have been known to be soldered to a thin and narrow piece of metal to be placed under an acoustic saddle. Fishman produces them and they're available at stewmac... |
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Post by reTrEaD on Jun 7, 2012 21:52:34 GMT -5
P.S. they have been known to be soldered to a thin and narrow piece of metal to be placed under an acoustic saddle. Fishman produces them and they're available at stewmac... erm ... no. The only part of that you got right is that Fishman does sell undersaddle pickups and they are available at Stewmac. But you couldn't be more wrong about how they work. What you refer to as the "thin and narrow piece of metal" is actually the active piezo element. In this case, the "cable" is just that. An actual cable that only carries the electrical signal. Not a "piezo cable" device. The only solder here is a small region to make the electrical connection between the element and the cable. You don't "Solder it to the base of your bridge" as you asserted in your first post on this matter. I'd suggest reading 4real's post. It has good information that could serve you well. |
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Post by 4real on Jun 7, 2012 22:08:32 GMT -5
I'm not wishing to instigate anything, but this is wrong plus, citing catalogues is not a reference. The impedance mismatch is way to great for both the mag pups which will be loaded and musical instrument amplifiers similarly. It certainly not as you describe. These things are pressure sensitive and you will find many projects here that use piezos and all have required buffering at least...even fishman's you will find...and so to the mags to match if seeking to blend.  As you can perhaps see, I have exactly the kind of piezo sensor you describe built into the bridge of my last guitar, there are other examples here in the last year. I can assure you that I and all the others would much rather prefer a completely passive circuit that does not require pre-amping or buffering to work effectively. It is true that you can use such an element, film, 'wire', buzzer or other piezo forms and pick up vibrations but it is not the case that you can just connect it up with conventional pups and 'instant acoustic sound'...it needs the impedance matching at least. If you assertion is that the 'wire' could be used instead of the 'buzzer' element, sure this is true. But, that does not seem to be what you are saying. It is more expensive but sure, anything would work, is it better could only be ascertained by comparative experimentation in the same application. In fact, I am impressed with your find for a source of such things as it does offer some potential for further experimentation in more innovative approaches that I am interested in, but you are naive in the idea that it is a 'simple' thing to connect up and go. Soldering to a bridge does not seem to be ideal, glue would do! ... A better approach that would not inspire animosity is to ask, why are you using this circuit, why can't you just connect a piezo with a mag or to an amp? ... I did see a ned steinberger piezo bridge from hipshot that claimed to work passively with mags as I recall, but can no longer find it and could not quite see how this could be done... Ah, here is a link...intriguing...what is "Differential™ piezo-electric technology"? store.hipshotproducts.com/cart.php?m=product_detail&p=366This would be very cool. Now, to work out how it is done and perhaps DIY, time for some patent searching. I have no doubt that this does not just entail soldering a piezo wire to a bridge though... [glow=red,2,300]EDIT[/glow] i light of last post No, there are flexibly shielded piezo 'wire' that is being referred too, it does contains piezo crystals and that is an interesting thing and I have similar things here of that type. My interest in them is the possibly, these could be cut to a small size enough to take independent signals from the strings, i.e. a hex pup...if included into there right kind of bridge design of which the one above incorporates elements with this potential. The interesting thing to these 'cables' is that they are sold by the inch and may be far easier to cut, perhaps even inserted into a bridge saddle through a drilled hole of some kind and in line with a string...at least that is my first thought. However, whether a flexible element like this, film type of more solid crystal structure, the rest is true, these things do require attention to impedances at the least, and often some EQing and other things to get the most of them. Mounting and position is a really important thing with a wide range of tones available from this kind of thing, as well as opening up potential problems. ... As for this project, there are a lot of interesting features, the hidden pickup is similar to things Leo himself tried and the choice of pickup is likely to be very complementary to the intended sound and application and an interesting choice. I don't think that the picguard and distance will be a problem though no experience with lace sensors. A recent fitting oa mini HB to my acoustic with thin bronze strings and a good 15mm from them or more gives a great sound and quite loud. The combination should attenuate the quack though not sure about the location for the buzzer to teh body, I've never hand much signal that way and a lot of handling noise compared to locating say on the trem block as john did and many others have. The finding of the piezo cable supply is a good thing, but alas it takes more than looking at 'product' to undertand how to put these things to use or to design and be able to assess a DIY pickup. Anything generally 'makes a noise' but is it good. Well, you need more than ones own ears and you need to hear it through various and quality amplification. ALl of these things take a lot of time and infrastructure, such as the tooling, I've heard it has taken real 'masters' 40 necks to really get all fo that right. I might as well add here, and generally this is found to be the case. That DIY guitars often cost far more than the equivalent quality bought ones. As a result, I've tended to modify, often severely, existing quality budget guitars and a lot of people here tend to do that. Further, my earlier modified guitars were basically junkers as I learned about such stuff, from garage sale junkers and parts as a teen, to good squiers and eden parts and the like. However, in more recent years and having played and owned good quality guitars, I have found that many of these things, built on a budget, approach $1000 in cost in parts and such to get the quality and functionality I desire. Most things need to be taken in stages, experiment with different aspects and cumulatively you start to work towards projects like this which are really interesting, functional and innovative. Stripped of too many bells and whistles yet striking. Piezos are no different, they are not hard to experiment with and can work effectively. I've still got teething problems with mine though and yet to see a really cool new application but this one is a very cool concept... |
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Post by sydsbluesky1 on Apr 9, 2017 0:01:38 GMT -5
As promised! This is likely something you considered and dismissed, but I did already fully describe it as random brain garbage. Here goes. Inspired by a guitar used by Omar Rodríguez-López live for a number of years, which had a single coil size stacked HB (Duncan, I think) at the bridge. I remember hearing, or perhaps realizing, someplace you have a proclivity for bridge pups over other options. I happen to have some blak plastic EMG active pups installed into a homebrew strat style (Work In Progress) guitar, so I did some fiddling. Lowering the bridge pickup to the level of the pickguard does indeed provide a totally usable sound. In fact, I believe it's very common practice to have at least the middle pups kept down flush anyway, is it not? I know I tend to hit them if I don't have them very low. Alas, I see you have a Lace Alumitone, so that particular thought might not be so useful. Very cool look to that pup, and surely not plastic... Especially not Mint Green plastic! Anyway, so much for that. But I wonder if a single sheet out of a multiply Mint Green pickguard could be delicately (tediously) cut for, glued to, scraped to fit and rest peacefully atop. It would only give you an extra -2mm or so, and I have absolutely no idea how those alumitones hold up under normal conditions let alone with distance. Add to that the active electronics! I got a perfectly reasonable volume out of my Bridge position EMG SA when flush. This having been said, I know my Duncan actives want to be a little closer to the strings that my Duncan passives, and this seems to be standard. A higher output passive pup might do just fine. Anyway, that's my random thought. ... But now I have a new thought! Was the Alumitone selection motivated by a desire to pair it with this particular project? Or was it just sitting around without a home when you were in planning? If it was paired intentionally, what was the thought process behind that? I see in the above posted video that the lad mentions higher output than a standard pup. Also the acoustic tones... Yum. I'm a huge fan of piezo paired with some mag and blended up, personally. Is the approach for this project an acoustic electric sound? Anyway, that's all. I'm not even sorry about the Threadromancy. |
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Post by newey on Apr 9, 2017 7:32:43 GMT -5
No problem there. The thread is old but the guitar is real, and still unfinished, I see it ever time I go into the music room. So, maybe this will spark me to get it done, finally. Real life has intruded for too long . . .
The Alumatone is already mounted below the pickguard. The inspiration for the whole thing was the pre-CBS Fender Marauder, which was a prototype that CBS killed when they took over.
We'll see if I get a usable tone with it hidden, if not, I can always get a new pickguard (or modify this one) for a more traditional mounting. I chose the Alumatone because, first, I wanted to try one, and second, Lace came out with a "lowboy" model that fits neatly below the pickguard without any additional routing (on a bathtub routed Strat body). But I'll keep your stealth idea in mind if it doesn't work underneath.
The other bit of experimentation is with the "homemade" piezo, which is the main reason this isn't finished. If that proves to not work as intended, the fall back plan is to get a set of Ghost saddle-mounted piezos. It's all a big experiment and I'm flexible moving forward- it's not like I need the guitar to play a certain way or sound a certain way, as there are plenty of other mares in the stable.
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Post by ourclarioncall on Feb 7, 2020 20:42:10 GMT -5
Did a google and found this old thread
A friend of mine bought a Strat with a piezo in it, you could blend it in with the pickups if I remember correctly. Think that was about 2010 but the model could have been earlier . Might have been called something something “power” Strat, maybe made in Mexico but not cheap
The 2016 Pete Townsend has a piezo too. I think it basically a Clapton Strat with a piezo and an extra pot positioned behind the bridge.
I’ve never been a big fan of the piezo sound on an acoustic/classical but the sound of a godin multiac is amazing. It has a piezo in back and another type of pickup under the cavity near the neck and think you can blend them both together.
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Post by b4nj0 on Feb 8, 2020 8:30:22 GMT -5
I have a high output Tele neck pup concealed beneath the pickguard of a home assembled Esquire. I think I got it from Guitar Fetish. It has a four way switch and delivers the series combo and is great for that, but in the neck position alone it lacks top end. I have never established whether that's a function of the overwound natureof the pup itself, or the relatively low position of it beneath the pickguard. It does make folks curious when they hear what's coming out of the 1955 Fender bridge pup! I would be interested to learn of your experience(s) with the hidden pup.
e&oe ...
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