curtisa

I think it was @Gogzs who suggested this one: string-through body or top loading. A new plank of tas oak was cut to the same dimensions as before (840mm x 65mm x 25mm) and a headstock of sorts added to one end. Instead of the headless hardware I've thrown on a single tuner from an old Strat copy and a Wilkinson WOF01 convertible bridge at the other end. This type of bridge can be fitted as a top-loader or for string-thru body threading. The old single coil pickup was installed as per usual into a matching rebate cut into the plank and then low-E, D and high-E strings fitted and swapped between top loading and string-thru threading options. Once again the plank rests on rubber feet and the robo-picker is doing its duty: With thru-body threading the string makes a 90-degree turn in two approximately 45-degree angular steps as it passes over the saddle: When configured for top loading the string does a bit of a zig-zag over and under the saddle on its way to the hole drilled in the rear of the bridge plate. My gut instinct is that this reduces the amount of downforce on the saddle which may affect how much pressure the string exerts against the body, perhaps changing the way the string vibrates? Audio files contain the following samples: Low E pluck thru-body, Low E pluck top load, pause Low E pluck thru-body, Low E pluck top load, pause Low E pluck thru-body, Low E pluck top load, pause D pluck thru-body, D pluck top load, pause D pluck thru-body, D pluck top load, pause D pluck thru-body, D pluck top load, pause High E pluck thru-body, High E pluck top load, pause High E pluck thru-body, High E pluck top load, pause High E pluck thru-body, High E pluck top load, end of file Unprocessed and simulated amp versions for you to chose your flavour. Like the scale length variations, I think the differences here tend to be more audible in the plugged-in recordings than the species of timber appear to have been. Also for @Bizman62's benefit, below are the sustain comparisons between the two string threading options. The results here shouldn't be compared to the ones posted earlier comparing the different species of timber. Because the new test plank has a 'headstock' and doesn't use the headless tuners I had to crack open a new set of strings to get some extra length to reach the tuning pegs. The initial peaks of the string strikes are also not the same as the earlier tests: 09 Thru Body vs Top Load + Amp.wav 09 Thru Body vs Top Load.wav

OK, well seeing as we're all rejuvinating... To get back to the thread reviver's point, there's nothing stopping you using neutral cure silicone to avoid the corrosion issue, although I've personally never heard of a truss rod failing due to rust that couldn't be traced back to severe moisture issues across the whole instrument, in which case a bit of corrosion on the rod is probably the least of your worries. There's also no reason to explicitly use silicone products either. Acrylic caulk used in kitchens and bathrooms would also be perfectly acceptable and is non-corrosive. It would also avoid any leeching of oils into the timber that @MiKro is concerned about, although again I've personally not seen that happen where a stain penetrated its way all the way through the walls of the truss rod channel to be visible on the outer surface of the neck. If you're in the habit of using trussrods that come fully wrapped in heatshrink you can probably do away with adding dampening materials in the channel anyway. The plastic outer covering tends to prevent any of the truss rod components from being able to vibrate against themselves or within the channel. Since I started using such rods I've never bothered adding silicone to the channel (or worrying about glue squeezing in for that matter) and have not had issues with rattle or fouled truss rod operation. Ironically the one neck I had issues with rod rattle was where I used silicone to bed in an Allied Lutherie rod, which were meant to be the gold standard for truss rod design. It was made worse by the fact that the neck itself was quite sensitive to seasonal movement, and required frequent rod adjustment. At certain times of the year the rod would be almost competely slack and would rattle like crazy. At other times I'd have to put a couple of turns on it and the rattle would disappear. The general concensus used to be that only a few dabs of silicone along the length of the channel was necessary to prevent the truss rod rattling in the slot. I would think that unless the slot was completely swimming in the stuff, the player's hand gripping the neck would have more of an impact in damping vibrations.

You guys do realise you're replying to a 14-year old thread, don't you? No, wait...

Calibration shouldn't be required that often. Once calibrated it should be good until something drastic changes like replacing drive belts, installing leadscrews with different pitches, swapping out stepper motors etc. Backlash or lost steps might reveal themselves as parts that change shape in subtle ways in one direction only. Think circles that come out slightly oval, squares that come out slightly rectangular or repetitive motions that start drifting in one direction the more they repeat. Go back to basics before writing off the CNC as being un-calibrated. Map out a simple square motion of known dimensions and see if it differs in size to what you were expecting. If it does then perform whatever calibration procedure is required to bring the machine/software back to spec. Then shoot the person who attempts to change it again. Another subtle error can occur if you're not allowing for the size of the tool when cutting. If your toolpath is designed to use a 1/4" cutter and you use a 6mm one by mistake you'll end up with parts that change size - internal cavities will be 0.35mm too small and outside profiles 0.35mm too large. Edit: corrected dimension errors if wrong cutter used.

Probably not very practical. The noise floor is so much higher in these recordings the sound has less 'distance' to go before getting buried in the background. You wouldn't get any meaningful data from it. Even if you could replicate the plugged-in recording characteristics I can't imagine you'd see anything different in the sustain readings. The string is still vibrating in the same way, the only difference is the way it's being captured - mike vs pickup. That's to be expected. The pitch will be governed by the mass and dimensions of the material. What you might find is that changing the 'pinch point' while holding the plank may excite or dull certain harmonic overtones in the struck sound, much like playing open string harmonics at various different frets. Again I'm not sure if that bears any relevance to the plugged-in sound or not. A couple of things I would add to the 'struck sound' melting pot of ideas regarding different materials. The amount of force I apply to get the wood to elicit a tone is enough to knock it over. The same can't be said about the amount of energy in vibrating strings going back the other way, so it's not necessarily a valid comparison to say that the acoustic sound of a plank being tapped will immediately translate to an equal amount of tonal colour to the strings output. The other thing that strikes me (hyuck!) is that when you play and hold a guitar is you cannot help but apply pressure with your hands, limbs and body at various points all over the instrument, which would potentially mute some (most? all?) vibrational resonances in the body and neck. A guitar that apparently rings well when suspended on a wall hanger and tapped probably won't resonate anywhere near as much when in the playing position.

Acoustic responses for all five timbers, also as requested by @Bizman62. Just one file this time with a single strike of a D string for each species. The second part of the file contains the acoustic tap response of each timber. Each plank was strung with a single D 0.026" string and mounted the same way as previously detailed, but without the pickup being fitted. A Rode M3 condensor mike was positioned vertically above the centre of the plank pointing down towards the pickup recess at a distance of 3". Recording was captured using the Presonus FP10 interface direct to disk at 44.1kHz 24bit. Note that the robo-picker has changed a little since the earlier photos were posted. I decided to remove the side-clamping action in case it was damping any internal resonances of the timber under test that may skew the results. The new mounting is free-standing from the plank under test. All recordings obtained thus far have actually used this newer variant of the robo-picker: For the tap responses, the same recording setup was used and each plank suspended vertically in front of the mike, again positioned 3" away from the back of the pickup cavity. The timber was gripped between thumb and middle finger at the same point for all 5 examples, 140mm from the top of the plank, pinching the plank at the edges to allow it to sound as clearly as possible. A single knock from my calibrated knuckles was used to get the timber ringing. Totally un-scientific, I know. But what you hear is the sound the timber naturally makes in the room when struck: Running order inside the file is: D-string pluck, tas oak D-string pluck, blackwood D-string pluck, celery top pine D-string pluck, radiata pine D-string pluck, kauri pine Tap response, tas oak Tap response, blackwood Tap response, celery top pine Tap response, radiata pine Tap response, kauri pine For convenience this matches the running order shown in the sustain table in my earlier post. Unfortunately there is more room and preamp noise in these recordings than the plugged-in ones. This is unavoidable given the extremely quiet sounds we're dealing with this time around. Regardless, headphones are highly recommended over speakers to listen to these unplugged string sounds. I'd also highly recommend downloading a copy of an audio editor such as Audacity so you can cut and shuffle these recordings around as you please to make your own listening comparison sets. FWIW, these recordings highlight the differences in the timbers quite clearly, although how that relates (if at all) to the plugged in sound is anyone's guess. 08 Acoustic responses.wav

A Telecaster would traditionally only have a 3-way switch to combine the two pickups, giving the combinations of <bridge>, <bridge+neck> and <neck>. The 5-way switch you've posted a picture of is usually used to allow the additional middle pickup on a Strat to be included to the possible switching combinations; <bridge>, <bridge+mid>, <mid>, <mid+neck> and <neck>. You can use the 5-way if you want, but you'll end up with a couple of positions on the switch that won't do anything or even give no output. The EMG-X bass pickups you've posted a picture of also require the use of a 9V battery for onboard power. There's also a requirement to use their much-lower value volume and tone pots to get effective control of them. If you're wanting to use one set of volume and tone pots for both necks it may not give the results you're expecting. Using the EMG pots you'd probably find that the guitar neck would have very weak, dull output. According to EMG if you were to use more traditional high-value pots (250k? 500k?) that would normally be used with your humbuckers, the bass pickups would work but you'd might find that the volume behaves more like an on/off switch rather than a gentle control across its rotational range. From a wiring perspective it sounds like you're essentially creating two Telecasters in one guitar, and instead of passing the output of the pickup selector directly to the volume pot, you feed it to the extra mini toggle switch to select between one neck or the other. The output of that switch then goes to your volume pot as per normal. All grounds in the system would be tied together and be fed directly to the output jack. Where you may be coming unstuck is the use of that particular 5-way switch and/or the disparate pots for each type of pickup, but photos of your actual wiring would help us provide more clues for you.

I'd have to get back to you on that. Note that the heavy/denser timbers (blackwood and tas oak) had shorter sustain in the bass, whereas the lighter 'piney' woods (although not necessarily pines as such) had stronger sustain in the bass. Given that blackwood is a close cousin to koa, itself a relative to mahogany, that seems somewhat at odds with conventional wisdom that says mahogany should be stronger in the bass than tighter-grained timbers. While I don't have any maple to play with, both celery top and kauri have very tight grain and high stiffness that would normally be associated with maples, which in turn are meant to accentuate the highs. The sustain figures here contradict that expectation, as there appears to be no appreciable difference on any of the high-E's across any of the example species.

It may help if you can describe what controls you want to install and how you'd like them to function in the guitar. It's a little unclear how you're wanting the 5-way switch to operate, especially given that you only have two pickups for each neck.

As per @Bizman62's suggestion, below are the averages of the three string plucks of each of the three strings for all five timber species. Each of the common string pitches were level-matched for the initial peak so that they all started from the same relative level. A noisegate was applied to each sample, adjusted to cut the tail off automatically once the level decayed to -50dB. The resulting files could then be easily checked to see how long they were. Interesting to note that sustains for the wound strings vary quite a bit between species, but for the plain strings they're all nearly identical. Whether that variance would become noticeable when played in a real life situation is unclear. All the strikes of the one string within a single timber species are pretty much the same (worst case variance is Blackwood low-E; 9.98sec - 10.84sec), which suggests that the robo-picker was capable of operating fairly consistently

You'd also have a pickup that gave diminishing output as you approached the 12th fret and almost no output for every fret after it.

For exactly one note. And its octave if you really want to stretch the theory a bit more. As soon as you fret an F, F#, G etc, placing the pickup at the 24th fret location to specifically chase that one harmonic node ceases to have any relevance to the note you've just fretted. @Bizman62s graphic simplifies the motion of a plucked string to make it easy to visualise how a sinusoidal waveform can be broken down into its harmonic components, but that's not how a plucked string moves in real life. It's true that moving the pickup closer to the 24th allows more of the lower-order harmonics to be captured which in turn translates to a warmer sound, but don't fall into the trap of assuming that the 24th position is the harmonically optimal spot to place it. It's physically and practically meaningless in a fretted instrument. You put the pickup where you want it because you like the sound of the result, not because it is mathematically correct.

Would that be so bad if that were the case? Realistically we'll continue to build our guitars out of whatever we feel like. Even if the stats suggest that tonally it makes no difference, that completely disregards what we or the paying customer may want aesthetically. A slab of pine will never be a substitute for the appearance and/or feel in the hands of spalted maple. And the other side of the 'wood matters' debate that this experimental test rig cannot solve is that the knowledge that you are playing a piece of mahogany, either by being able to see it, feel it or be reliably informed that it is in the guitar by some other means, may influence how you play the guitar, which in turn could change the tonal output. That was primarily why I didn't want to provide screenshots of spectrum analysis and instead only focus on the sounds. There's no real advantage in trying to see the difference if you can't hear it, or trying to find the visual reason why sound A does sound more bassy than sound B. We don't play guitars by looking at the output jack. The other way I think we should all be approaching it is asking ourselves, 'how likely would I be able to have heard the difference if I didn't have the comparison handy in such a clinical and controlled fashion?' If the answer is 'pretty unlikely' then perhaps the argument raised by some people that wood matters almost insignificantly holds more water than we give it credit. I would probably use the qualifier 'detectable' to any assessment of a guitar's output based on these recordings, rather than 'big' or 'small'. Most players know what a 12-month old set of strings sound like and don't need to hear something to compare it with to know the strings sound worn out. You probably couldn't say the same thing if you were asked to assess a set of strings 24 hours old and say whether they're 'brand spanking new' or '1 day old'. To me this is where wood A vs wood B sits - I think the difference needs to be much bigger than what's in these recordings to be able to categorically say that a choice in timber based on species alone can make or break an electric guitar from a sonic point of view. If all the differences are really tiny they'll get lost in the noise, even if they do stand out when played side-by-side through the magic of audio editing. In reality it takes us 15 seconds to unplug the alder Tele and plug the pine one in - how much of our memory of what the first one sounded like 15 seconds ago can we rely upon?

By and large I agree, but the results I seem to be pulling out of this experiment may suggest that the wood used makes such little difference in and of itself that it could be completey disregarded as a contributing factor. It may raise the possibility that people who claim to have swapped a rosewood neck for a maple neck on their Strat, noticed a change in the sound and attributed it to the rosewood are incorrect. That given it takes them 30+ minutes to do the swap, unless they go to the trouble of making recordings before and after and comparing the results in a very clinical manner they may be imagining they're hearing a change. Or, if there is indeed a measureable change that perhaps they should be looking at something else other than the rosewood as the reason why it is different. Same may also apply to people who are building a guitar and chosing timber expecting it to sound a certain way. Chosing alder due to the expectation the result will be 'snappier' may be false. Chosing mahogany becuase the result is expected to be 'warmer' may be false. That chosing a piece of wood based on how it sounds when struck may be pointless.

One string of each or three of each? One pair of each implies a single example string of each, in which case - which string? Bearing in mind that it's been suggested that the differences seem to become hard to hear depending on which string is played. Hint: the wound strings are easier to make last longer when strung/tuned/detuned/restrung...

Personally I can hear really subtle differences between some of the timber pairs when they're played back to back. But they're super-borderline, to the point where if I went out of the room for 20 seconds to put the kettle on and came back, if I started playing one sample at random I'd never be able to tell what I was listening to. They're certainly not the earth-shattering differences some people claim to be able to hear when comparing identical guitars made from different timbers.

That should be reasonably easy to cobble together. Something along the lines of how long it takes for the sound to reach some nominal level, which doesn't necessarily have to be the threshold of silence. Say, measure the time taken for the note to lose 75% of its initial peak, or the time taken for the note to decay to an absolute dB value. I reckon you'd lose perspective with so many choices at your disposal, and the relevance to the sound produced when plugged in seems somewhat tenuous. What about if I recorded acoustic samples of the sound of each species when knocked as a compromise; one file for each species and leave it up to the listener to shuffle them around at their leisure? It's quicker for me to produce and will probably be easier for you to hear differences in the raw acoustic properties of the materials.

Some more comparisons for your examination. Same deal as before: 3x2 strikes of a low-E, D and high-E, each example alternates between two timbers. The 'new' timber is played first followed by the tas oak (weight = 1140g, typical Janka = 6000N) for reference using the following pattern: Low E pluck <new timber>, Low E pluck tas oak, pause Low E pluck <new timber>, Low E pluck tas oak, pause Low E pluck <new timber>, Low E pluck tas oak, pause D pluck <new timber>, D pluck tas oak, pause D pluck <new timber>, D pluck tas oak, pause D pluck <new timber>, D pluck tas oak, pause High E pluck <new timber>, High E pluck tas oak, pause High E pluck <new timber>, High E pluck tas oak, pause High E pluck <new timber>, High E pluck tas oak, end of file. Strikes within each pair have been separated by a short gap as per @Bizman62's request, plus the fadeout of each sample is a bit gentler. Amped and non-amped versions are provided, with 30% less dog poo-poo for @mistermikev's benefit . Each timber plank used had the same dimensions. Hardware, electronics and strings were the same for each. Mounting positions for the hardware and pickup was the same. Robo-picker was set to the same location, speed, string/pick engagement. Same everything everywhere (to the best of my abilities). Only the timber differs. 04 Radiata Pine vs Tas Oak: Radiata Pine weight = 650g, typical Janka = 3200N. No other changes to the earlier version other than to provide more space between the string pairs as per @Bizman62's suggestion (note that this recording is the same file as before, except that the samples within are moved around a bit) 05 Celery Top Pine vs Tas Oak: Celery Top Pine weight = 794g, typical Janka = 4500N. CTP is not part of the pine family, but adopted that name owing to the early English settlers in Tasmania naming it based on its coniferous appearance. 06 Blackwood vs Tas Oak: Blackwood weight = 856g, typical Janka = 6000N. Blackwood is a close relative to Koa, so that probably makes it as close to mahogany as I'm likely to get my hands on at the moment. 07 Kauri Pine vs Tas Oak: Kauri Pine weight = 860g, typical Janka = 2500N. Also not actually a pine, Kauri is part of the Agathis family. I need a drink... 04 Pine vs Tas Oak + Amp.wav 04 Pine vs Tas Oak.wav 05 Celery Top Pine vs Tas Oak + Amp.wav 05 Celery Top Pine vs Tas Oak.wav 06 Blackwood vs Tas Oak + Amp.wav 06 Blackwood vs Tas Oak.wav 07 Kauri Pine vs Tas Oak + Amp.wav 07 Kauri Pine vs Tas Oak.wav

A lot more. I'm using 2 second windows of each, but the unadulterated decay of them is between 5-15 seconds each depending on the string played.

The two samples are back-to-back with no overlap or crossfading in between. Interference between the first and second samples could be the way we interpret unnatural sounds occurring in nature. The pick attack at the start of the second file would not normally take place hard up against the tail of the preceeding note in real life. I suppose you'd normally expect some choking off of the tail of the first note for a fraction of a second as the pick comes in contact with the string for the second strike if it were two plucks of the same string played by a human on a real guitar.. The tails of each sample are deliberately and artificially cut off, which again is not a natural phenomena, and could be colouring the interpretation of how the two samples sound and interact with each other. I suspect this is one of the shortfalls of Ola Strandberg's tonewood video I linked to earlier as well, as it sounds like he's also butted all the samples up against each other to try and make the sound comparison easier. The tradeoff being that we may be misinterpreting some of the detail because our ears hear one long continuous noise with a distracting join in the middle, rather than two discrete sounds. I can repost them again with a short gap between and less-abrupt fade-outs if you think it would help? It's actually pretty hard to decide the best way to present some of these comparison files. I don't want to make the samples too long though, as that also makes the comparison difficult if you have to rely on your memory too much when comparing two sounds. I get the impression that the shorter the gap between examples improves the chances of being able to detect differences between two sounds. Leave it too long and you 'forget' what the first one sounded like.

Just to be clear in case I've used too many words, using file 04 (take you pick between amped or non-amped versions): The comparisons should not span across adjacent samples separated by a 'pause', otherwise it becomes too difficult to reliably remember what your reference point is.. The strikes within each pair are purposely placed back-to-back to give you a fighting chance to quickly identify any differences there may be between the two timbers.

If we're talking about file '04 - Pine vs Tas Oak', then yes - correct. The samples always alternate between the two. There is no randomising going on. So what is being played in the recording is: Low E pluck pine, Low E pluck tas oak, pause Low E pluck pine, Low E pluck tas oak, pause Low E pluck pine, Low E pluck tas oak, pause D pluck pine, D pluck tas oak, pause D pluck pine, D pluck tas oak, pause D pluck pine, D pluck tas oak, pause High E pluck pine, High E pluck tas oak, pause High E pluck pine, High E pluck tas oak, pause High E pluck pine, High E pluck tas oak, end of file. I would suggest that if you are hearing something different between pairs of plucks that can't be consistently identified as one or the other within each pair (eg, you can reliably identify the first pluck in each pair always sounds darker than the second) it is minute differences between the plucks produced by the robo-picker. Two plucks will never be 100% clones of each other no matter how good the mechanism is, but they will be more consistent than any human can manage, which was my main intention here. If there is something intrinsic about the two timbers that makes pine sound different to tas oak (or ash vs alder, or mahogany vs basswood, or poplar vs black limba etc) it should stick out like crazy each and every time rather than flip randomly between sample A and B within each pair. If the running order of the samples does not change and they sound appreciably different then the 'tonewood' theory should make it easy to identify the two samples when played back-to-back. The raw recordings are identical, just that the clean file is fed through the amp sim to generate the 'amped' version (my apologies if the amp sim doesn't sound so crash hot, I just grabbed the first one I could find in my DAW and left all the controls at 12 o'clock). The amped version does not use a unique group of string samples compared to the clean version. Again, if you've managed to identify that pairs of plucks are different but the difference within each pair is not consistent, I'm tipping microscopic differences in the motion of the string once plucked by the robot. However, given that the amped and non-amped recordings utilise the same base playback file, if what you can hear is (assuming I've understood your explanation correctly): Amped version of low-E strings: (two samples are different), (two samples are the same), (two samples are the same) Clean version of low-E strings: (two samples are the same), (two samples are the same), (two samples are different) Then perhaps it suggests that the samples cannot be reliably distinguished, as the <different> samples should have fallen in the same position in both recordings.

Yep. That was my thinking in chosing pine as the comparison material. If an alder Strat, a basswood Strat and an ash Strat are meant to sound uniquely different then surely two disparate woods such as pine and tas oak should sound different, even if few people are familiar with them as materials. I have other species at my disposal which I want to try out, but again they won't be familiar to anyone outside Australia. That may be a good thing, as perhaps most people won't have any preconceptions as to how they should sound? Seriously though, if anyone wants to donate a plank of one of the commonly accepted tonewoods to try out I'm more than happy to run it through the tests

I could, but I also think that the first comparison I did (pickup directly mounted vs free-floating) suggests that the pickup can only 'hear' the strings' motion, and not how the wood 'sounds' acoustically. The unplugged response of the guitar might be interesting but it's probably not particularly relevant to the sound that emerges from the amp in and of itself. Sustain tests are another interesting possibility, but it's one you'd have to be careful approaching. Essentially you'd need to be able to reliably differentiate between the length of single notes disappearing into the noise floor that might only differ by a second or two over 20 seconds or more. It might take significant differences to reliably detect, in which case you'd probably argue that the guitar with the shorter sustain was probably broken

FWIW, it's not a given that the two sample should or shouldn't sound the same. I've only compared one example each of two different species in the previous test, and two woods that many people wouldn't use in their builds at that. It could be that tas oak 'sounds' the same as pine anyway. There could be something in my test rig that is unifying the results somehow. While I would like to extend this test to include the more commonly used woods like mahogany, maple, alder etc, I'm a bit hamstrung with these species as they're so bloody expensive and hard for me to obtain down here. However the initial run of results based on two common materials with substantially different properties, while keeping all other aspects of the instrument and the way it is played identical (ie what should be the backbone of any of the numerous tonewood comparison tests out there) could indicate that the wood doesn't make a difference to the sound (or perhaps at most, a difference that disappears into insignificance).