pan_kara

So here's a little sample from my current initial study that will probably form episode one. I recorded a series of notes on an open A string, hitting it in different ways: note 1: normal pick, normal position a little in front of bridge HB 2: back - above bridge HB 3: front - above neck HB 4: middle - above 12th fret 5-7: soft wood pick, normal position 8-9: hard wood pick 10-11: shell pick 12-13: finger pluck 14-15: metal wrench Then I did my analysis on 40 (!) harmonic components of the sound. Yes, with the piezo I can still make out the 4400 Hz overtone from a 110 Hz low A - though it dies out completely in 0.5 seconds. So for example here's the 440Hz overtone - aka 2 octaves of the 5th fret natural harmonic: You can see that it can be of different strength initially (for example over 90dB when plucked with a hard shell pick or about 70dB when plucked with a finger), but the exponential decay is nearly identical across all notes. The only thing is the weird oscillations present in the 3rd note. Overall the overtone decays at 5.4 +/- 0.4 dB/s (average from the 15 measurements). If we look higher, for example at 996 Hz, we have this: still pretty consistent, though the oscillations appear to be confusing the straight-line fit a little so there's a bit more variation, overall we clock 10.6 +/- 1.2 dB/s. So what are these oscillations? For some frequencies they're there always (though can vary in size), and for some they come and go depending on the note. In general this type of modulation is a sign that the oscillator I'm looking at is coupled to another oscillator of a similar frequency, in which case energy will flow back-and-forth between them, causing this modulation on top of the normal exponential decay. The "other oscillator" can be several things. First of all it can be the other transverse component of the vibration - the piezo is mostly sensitive to up-down motion in the guitar plane (into-away from the bridge), but there is also the sideways motion that can in general have a slightly different frequency. The string is not anchored in the same way in these two directions, for example it might move a little side-to-side in the saddle, thus detuning the "sideways overtone" slightly and causing this "pumping". This I managed to observe in fact, I did a test with another guitar plucking the string with the same pick, in the same place, but with different motion, trying to have more of the sideways vibration one set of notes, and more up-down vibration in the other set. And indeed for some harmonics I see the modulation only appear (or be more pronounced) in one of the groups. For example: and: (first three notes are hit in one way and the subsequent four in a different way) For some overtones it's less clear, sometimes the vibrations are there in all cases, sometimes the behavior is more erratic. But it does appear that their presence is in most cases correlated with the type of pick attack. What this means is that if I try to maintain a consistent style of picking for all studies I will probably get a more uniform set or results since the straight-line fit is a bit sensitive to these oscillations. On the other hand I don't see a systematic effect (like pulling the slope measurement in one direction when the oscillations appear), so in the end I should be fine whatever I do. Other things that could be causing these oscillations could be the interference with longitudinal vibrations in the string (there's also torsional vibrations i.e. the string core rotating around it's axis, but it appears that those can be ignored) or vibrations is the "rest of the guitar". Both are something I just have to live with - it will be interesting to see how that pattern changes when I change different components of the system. But that's for later.

I have thought about things and went through a bunch of literature that I could find online. I'm not sure if my method will prove fully correct, I guess we'll have to look and see. I'll wait until I have some solid conclusions before I start putting this series on youtube And of course there are many variables here, I'll have to split them according to which ones I can control, neglect, or have to take into account. For example the string pluck does play a non-trivial role as I'm now discovering, most likely due to the delicate relation between the two perpendicular string vibration modes (up-down and side-to-side). But looks like my method is still holding up in general, I just have to be mindful of that. As for strings, well, here's my starter purchase - 10x sets of 3 strings for tests plus low E going from .042 to 0.054 in steps 0f .002. And a few nuts - brass, bone, graphite (I already have tusq and plastic). The guitar that I'll be using for most of these tests is my old nylon string build - because I want to do as much as possible with a piezo. Piezo gives me a much broaded palette of overtones - they reach higher and are not attenuated due to phase-cancellations (something I was trying to mitigate in the past by recording both bridge and neck pickup simultaneously in stereo and then picking the one with better amplitude for each overtone separately). As a bonus - I have no magnetic pickups here so any influence from those is automatically removed - but can be added in if I want to test it, by suspending a pickup above the strings in a location mirroring actual position in a guitar.

well to me it's not the transparency that is the problem, that I quite like actually. But I think the large uniform black area (with a white edge) somehow offset the complexty of everything else going on with this guitar. So I think I'll go back to the black simply, saving the plexi as an option for whenever I feel like changing. I just need to level and buff the lacquer before the re-assembly

Ok, time for some thread necromancy wow, this really is from 2014... ? ... ? oops So I'm bringing my "tone" investigation back to life. It got interrupted because I couldn't get consistent results and didn't understand why. At some point in time I think I did manage to figure out what was happening there. In short: My main idea was to try to see if I can find some numerical differences between the string overtone decay rates when comparing the Schaller Hannes bridge and some cheap hardtail. In the end my main problem appears to be caused by me having reused the same set of stings for all measurements - the idea was for that to ensure consistency, but it ended up messing everything up because the strings got deformed at the saddle break point and due to different mounting this kink then ended up in the "active" (vibrating) part of the string when swapping bridges, causing totally unpredictable results... We'll I'll be more careful this time. Right now I'm trying to again establish the framework, including verifying various assumptions that I'm making. The main idea is (repeating some of the stuff I was mentioning earlier) that to study "tone" one should look not at the spectrogram (frequency content) of the sound of a plucked string, because this will depend strongly on a number of factors like type of pick, picking position, picking strength, picking motion etc etc Instead we should look at the time dependence - how fast the individual overtones decay. This is largely independent on the initial conditions (picking) as the decay speeds are at the end of the day the result of properties of the guitar-string system itself. So is it really them that define the "tone of the guitar". In such an approach where I decouple the initial conditions all experiments are much easier (no need so special jigs to replicate series of identical string plucks), plus I also take all electronics out of the equation (except for things like the magnetic field of the pickups influencing the string motion, something that we already discussed in this thread and something that I plan to address at some stage) - I'm really looking just at the string vibration itself, the source of the sound. Pickups come in later and shape it. So what's the plan now? I'll try to release this as a series of youtube videos, and possibly also a write-up of some sort. Plus regular updates and hopefully discussion in this thread. I'm nearly done with the opening part, which is experimentally demonstrating that indeed the pick attack doesn't influence the results. Then I have a series of simple comparisons lined up - how the sound changes when changing fret material, nut material, string gauge .. maybe a few like that, before I'm confident I can attack everyone's favorite - wood choice. More soon

I didn't try the flame test, but weld-on didn't seem to work. Maybe I messed up the surface preparation on that instance. Anyway ths superlglue is still holding and meanwhile I finshed the plexi version. Not sure I like it, I think I'll revert to the black one. I like the "exposed wires" look and the fact that more of the swirl is visible, but I think the black picguard somehow balanced the design better.

I think that's close enough to invisible. If you look at the reflection you can see that the surface is not completely flat - I didn't want to sand too heavy since this weird material appears to be completely un-gluable. Today the epoxied bit fell out when I started on with with micromesh pads, I managed to glue it back in using superglue with some "activator pen" that I found laying around. Probably will fall out during a gig though it did survive a careful sanding and buffing session.

Sure, the front is covered, but at the back it might prove tricky .. unless you're gluing them in some other way than what I'm thinking you'll get non-parallel lines in both pieces so - if you align the bottom before carving the profile, they will go out of alignment when the neck is carved - since one piece is at an angle, the widths of the laminates are different (though this is a 2nd order effect and possibly negligible) nice wood porn BTW, that V with the buckeye top is stunning

sure, I have a lifetime supply probably, it was really just laziness ... The repair is promising so far, after one failed attempt with epoxy I have a piece glued in and trimmed flush. What remains is polishing up the black surface, if I'm successful with that then the pickguard will be ready.

hah looks like these sanding beams are also available in Europe. I think I'm going to get one, my old leveling I-beam (or whatever that's called) that I used for this is now dented in the middle. Good luck with that inlay project, can't wait to see how it turns out! I vote shell for the beard

nice job with this ebony edge. I always struggle with that bit

Here's a video I did some time ago about a guitar I built for my daughter's 7th birthday. Initially I didn't post it here since I figured this is not really the target audience, but then maybe somebody will find parts interesting or amusing. Also I watched @sdshirtman 's videos and figured why not (BTW where is part 6 of the Helix build??! ) So just a word of introduction: I tried to film every part of the build process. Some parts are missing, mostly tedious jobs like sanding etc, also I think I lost a clip or two - but in total this was something like 9h of video material that I compressed into 13 episodes of around 10-15 minutes each (mostly by speeding up the footage). There is a lot of narration because the aim was for the video to accompany the guitars, i.e. I'm explaining the build process in a way that someone with no idea about guitar building could understand. Possibly even a 7-year-old. Also (as I keep stating in the video), this is not a how-to, it's more of a "proof that you can build a guitar in the kitchen" video. I'm probably doing some silly things here or there, but the end result is perfectly fine. Oh, and it's all in Polish - but I subtitled the whole thing in English. Anyway, here's the playlist with all episodes:

aah the part that always messes with me. Are you going to try to align the laminations? Actually with compound scarf it's impossible I think, due to the two pieces being at different angles .. so accent laminations then?

nope, not carpet tape, I bought a roll of that 3M stuff that you were reviewing. It's fantastic in general - it just pulls up so much fibers from the mdf that it jams itself. But that's clearly user error. I don't have any more blank pickguard material, the sheet I used ended up enough for two (the original one and this "fixed" one). I still think it can be done as long as I manage to glue the damn thing in place, epoxy is curing right now. It's black side up so I think it should be possible to spot sand and polish everything .. on the white side the repair is much more apparent. Another option is plexi, I bought a 3mm piece on the weekend, I want to have a transparent version too to try, not sure at the moment which one I'll end up liking better. Maybe I'll manage to not mess up that one.

I'm actually going back and forth a lot between narrow and wide(-ish). In the end it's probably a matter of getting used to, at least to some extent. It so happens that my most preferred 36.5mm E-e spacing is modeled after a guitar that I'm playing since '96 or so... A 7-string that I frequently play has 41.2mm spacing B-e, so E-e that's 34.4 - I suffer any time I have to play clean arpeggiated chords in the open positions. Hell, my Strat copy has 35.3mm and that's already annoying. .. just googled "graphtech gibson" - if their 6010 nut is representative of "gibson standard" then that says 36.2mm. So yea - that's what I'd consider perfectly normal.

Thanks Andy. I'm trying to do the guitar justice and finish it up properly, but my limitless supply of stupidity keeps getting in the way. I was routing the pickguard, the original one had all sorts of problems - the pickup routers were a tiny bit too small and anyway not shaped exactly, the pickup mounting holes were off a little, the cutout for the bridge was too big, the mounting holes were not equal distance from the edges etc etc. So I took extra care in making a new template. It's pretty much spot on, but I did manage to misplace the middle pickup route by a mm. I marked that on the mdf and figured I'd just route that last and shift the template for that. Well guess what. I did remember, but when shifting the template back and forth I kept using the same 2-sided tape, after all it was still sticky, what could go wrong? Well, this: Of course it wasnt attached firmly enough and I ate into the pickguard while doing the bridge pickup opening. I figured this should be possible to fix with a scrap piece, the piece is in fact in the picture. So now I'm trying to glue it in place. I thought I'd melt it in with acetone like binding, but this appears to be a different kind of plastic, acetone does affect it slightly but not nearly enough to glue the pieces together. I tried superglue, nope doesn't hold. I tried weld-on binding glue, seemed to hold but fell off the next day when I was trying to trim the new piece with a chisel. Looks like I'll have to mix up a drop of epoxy for the job ...

Padauk rocks. I love all the little insert thingy's all over the place. Great work! Man I have to finish up my "tone analysis" framework, I even have a thread buried somewhere in here about that - once I have that I'll be asking all of you guys for sound samples for analysis

mine is probably a lower-end model, I freed it from fret pressing via the press and then I got a spindle sander to free it from sideways pressure.. Concerning tang size - I think my saw is also a tad too narrow for the 6105 dunlops that I'm mostly using, I'm under the impression that all of my necks go into backbow after fretting (and carving, straight after fretting they're still not carved so manage to resist). I think I nearly maxed-out a 2-way truss rod on one of them just trying to get the neck back in shape (with strings on). So this is another thing to take into account

Actually not madness for me, I also like to tweak the neck profile late in the game, I'm not sure I ever did this with strings on but I could have. But I see how this saved you on this occasion. oh and for the record - I absolutely hate narrow nut spacing

just one comment on using a drill press for frets - I'm not sure drill presses are meant for this amount of pressure, I might have messed mine up a tiny bit by doing exactly this, it now has a small "hiccup" when lowering the spindle at one point. So I just went ahead and bought a small arbor press and I use that now.

I think I found a supplier and I have an idea for an in-progess build actually might be cool in a swirl too, would need to check how the paints tolerate the pigment, but should be totally doable

wow nice save. I absolutely hate narrow fingerboards. I also had to save myself with binding last time, but that was before frets went in (error when cutting fingerboard taper). I'm not sure what I'd have done if I discovered this after fretting ...

Yea, they had this thing at the bottom of the can where you pull and twist to mix the hardener in. I think it was "duplicolor" so the brand that has all the auto spray paint in hardware stores all over the place. That's where I got it in fact. Maybe if I could source a better quality 2k that would work better. Not sure whether the problem is me or the paint at this point though BTW second set of coats of nitro going on right now, plus I routed a new pickguard and messed up in a completely stupid way, I'll post that with a pic later on. Trying to get it fixed now.

I like the creative approach to some multiscale-specific thing here: compoung scarf? who needs one, I'll just do a normal scarf and tweak the fretboard edge. Also a cool solution on the other side too! (bridge end of the fb) And the bridge - is that wilkinson saddles attached to a wooden block with custom screws threaded into the holes where intonation screws normally live? that would be another novel solution! Will it work ok with no baseplate however?

wow this looks awesome! and cool design damnit now I'm gonna go online looking for glow in the dark powder ....

wow and I thought I was slow