dh7892

The GK needs seperate signals for each string so you'd have to build a buffer for each string. I'm not really sure what the board for the internal GK pickup does. It might just be routing the wires from the cable or there might some pre-amp stuff going on. If it's just routing then you might want to miss out the GK board all together and wire it up yourself (with your own buffer pre-amps) to the socket (including switches and volume controller). I'm build a guitar at the moment and I'm planing on only having a GK pickup as I use a VG-99. I though about getting the Ghost system as it would look a lot neater having no messy looking GK pickup but they are expensive as you say and I've heard bad things about how the VG-99 sounds with piezo signals. They've put a patch out that's supposed to sound better but I already bought the internal GK kit

In general, I'm pretty impressed with the upper access on my Jem but, if I'm doing wide interval runs above the 12th fret, I find that the pointy bit on the end of the lower cut-away gets in the way of where my fretting wrist wants to be. (I have to drop my wrist down in order to get the reach with my little finger). For this reason, I plan to build a guitar with little or no horns on the lower cut. I also like the idea of neck throughs so enable nicer shaping near the 24th fret (but I do think Jem does about as well as possible for a bolt on)

You could do it with three single-coils with a phase switch for the middle one so that when you put the middle next to one of the end ones, you can get it to act like a humbucker.

Thanks for the info, I'm down in Kent so David Dyke and Exotic Hardwoods are quite convenient for me! I tend to fall into the trap of looking at catalogues online and they never seem to have the really juicy stuff in them. I guess you have to phone up of pop round to see their latest stock and pick out some really nice bits.

Skelf, I'm lovin' your basses, where do you score your wood from here in the UK?

I did A-level psychology (as a kind of fun, extra subject!) and I think that some of the experimental methods /procedures we used there were more sound than I see people using in my work today. Since psychology can very intractable experimentally, it becomes almost more important to be very rigorous with the stats and method (even if the underlying statistical understanding might not be there). So don't do yourself down! I agree with Aidlook that you should try to make the setup as close as possible to the "real" thing because then your results will be more relevant to the real situation of playing the guitar. I wouldn't do anything at the expense of being able to pluck the string consistently though because I think that's a more important factor in the results.

@WezV: I'll admit that I was being a bit verbose about the subject but I was really trying to address Scrappy_Squirrel's comments. To simplify: He IS changing only one thing at once (the bridge). I think his posts show that he has a very good grasp of what is required here. It's others' comments that I'm not so sure about! @thegarehanman: I'm proud of being a scientific snob. There's no point almost making an insight into something. You've got to do it properly or you may as well not bother. Worse than that, you may think you've learnt something when really you've just mislead yourself. I think the OP has demonstrated enough of an interest in doing this project well that he would enjoy being a science snob too so I might actually be encouraging him! Sadly, I'd not be particularly keen to recommend to people that they aspire to science (at least here in the UK) given how undervalued science and engineering is regarded here (and I'm not just talking about pay either).

The original post states that the aim of this work is to demonstrate use of the scientific method. Here’s what I think the scientific method is: Decide a Hypothesis (and a contrary null hypothesis) and devise an experiment that aims to test (to a level of statistical significance) which of these two hypotheses is true. If your hypothesis is something like: “Bridge A provides longer sustain than bridge B” then your experiment is fine. If you were trying to provide a comprehensive investigation into all possible types of bridge/material etc. then you’ll need to do more tests. But you know this. You also need to make sure that you account for any (significant) factors outside your control. You also know this which is why you’re repeating your pluck because you know that there’s likely to be a relatively large random error in these. You’re also trying it with different strings because you know that “sustain”, as you are interested in it, might be different across a range of frequencies. Changing more than one thing at a time most certainly does NOT mean that your results are meaningless. It might mean that you can’t say exactly what causes the sustain (is it bridge design or material?) but that’s not what your trying to investigate so that’s fine. By the way, in big experiments (like pharmaceutical/farming trials) they deliberately vary several factors at each trial and use statistical methods to back out the importance of each variable. It’s called Design of Experiment technique and you really wouldn’t be able to make much progress without it. Sorry for the scientific high-ground taken here but I’m a research scientist and I think the scientific method gets abused all the time and it’s a shame because it’s really the only way to provide insight into anything. Science is not a PITA, it’s about deciding what you want to know and devising a way of satisfying yourself about the result. Yes you have to be clear and precise in terms of your aims and methods but that doesn’t mean it has to be onerous. I think you’re doing a good job here and I’ll be waiting with interest to see your results.

So the strings will be struck a bit like a piano? Like you say, you'll need to do a few repeats of each pluck. How will the plucker fall? Will it be moving towards the pickups or across the face of the guitar?. Perhaps it would be easier to pluck by gripping the string and pulling it out a fixed distance and releasing it. This way you only have to worry about the release mechanism to make sure it's a clean release. I think this is more repeatable than trying to hit the string in the same way each time with a falling object.

I think it's great that someone is doing this. It will be good to have some actual data to refer to rather than just people's anecdotal "evidence". How are you going to pluck the string? Obviously you'll need to try to make each pluck the same. Are you going to do any type of frequency analysis on the notes too? How about the sustain of different notes since different frequencies will transmit to the bridge/body differently. Make sure you post your results here as I for one will be very inrerested

I've got a 555 too and, like you, I've got terrible problems with the trem. I'm wating for a few bits to arrive before building myself a replacement "main guitar" but I will be trying my best to copy a lot of things about the 555 that I really love. The neck plays really well and I love the tone of the pickups. I've no idea if a proper JEM would sound the same or better (I can't afford a real one!) but, like you say, apart from the trem, they're nice guitars.

Nice work. That's very much like a jig I was thinking about building (I posted here about it a couple of weeks ago) but your's has the added functionality of setting the angle of the side rails. Nice.

Thanks for that. I think I'd decided already that I'd go with a sliding type arrangement rather than actual bearsings so these ideas give me plenty of food for thought. I thought that someone was bound to have do this kind of thing already.

Thanks for the extra info. I'll be sure to check it out.

I was worried that the drawer sliders wouldn't be up to it. I had a look at linear sliders/bearings (mostly from CNC companies) and they are a lot more expensive like you said. I too though about miter slots and it may well be that that's what I end up doing. I was kinda hoping I would end up with something where I could move the router around pretty easily. A bit like using it free-hand but without the worry of it tipping on the edge of the workpiece and with the ability to use it like a ski setup for surfacing and thicknessing wood.

First, a bit of background: Due to accommodation constraints, I can only do any guitar building outside or on a bench I've rigged up in the spare bedroom . For this reason, I don't want to use any fine dust making power tools (in particular my router) inside. When I'm outside, I only have a workmate to work on so it's not exactly a large, flat, stable surface. Because of this, I'm thinking about making a kind of router platform that would use a reasonably large (i.e. big enough to get a guitar neck or body on) MDF base and then fit parallel sliding rails on each side with cross rails joining them at right angles and the router mounted in the middle. This would give me a kind of router sled/table thingy where the router base would be held parallel to the MDF base and the movement of the router constrained in the x-y plane (with z controlled by the plunging action). This way I would be able to set the parts in position with any jigs required whilst I was indoors and the only have to move outside (into the unreliable British weather) to do the actual cutting. It would be a bit like a CNC 3-axis routing machine but without the CNC part! I was thinking about trying to use drawer sliders for the rails with some MDF under the cross members to provide the necessary rigidity. I've had a good Google to try to find any examples where people have done something similar but drew a blank. Any of you lot seen/tried this? Suggestions, advice and comments most welcome.

One last quick thought about elasticity (since it's not really the main point of our discussion): I think it's all a matter of timescales. I agree with you about the fact that the string holds its shape from the tuner. This plastic deformation happens over a much longer timescale than a vibration of a string. Even though the string may creep if deformed and held for a longer time, this plastic deformation will just provide a new "starting position" for the string. Any (small) movements away from this "neutral" position will result in elastic deformation. The string will still try to return and hence oscillate. What you've said previously about kinks in the string will no doubt affect the neutral point of the string and hence (implicitly) the shape of the vibrations on the string but I'm still not sure that the elastic response is less. When the string truly stops being elastic, I think it will break almost instantly. In other words, I don't see how it can gradually lose elasticity without reaching critical failure strain very quickly. You also raise a good point about nylon strings. As an aside, did you know that some polymers (I'm not sure if it applies to nylon but it certainly does apply to elastic bands) behave contrary to most "normal" materials in their response to temperature. Most things get easier to stretch when you heat them up but polymers are harder to stretch when hotter. Not really relevant but interesting isn't it? With regard the main topic of this thread. I invite someone to do a little experiment (I'll try it myself when I'm next re-stringing one of my guitars): Try fitting some form of collar (a tight fit would be important) of some noticeable mass (perhaps wrap a bit of wire?) around a short section of string near the bridge and observe the following: How does the string sound when plucked? Any nasty harmonics? Is the intonation affected? In which direction and by how much? What happens when you move the "mass" along the string? What happens if you increase/decrease the mass? How annoying is it to realize that you've just made your guitar sound terrible on the whim of some bloke on the internet and you now have to re-restring it?

Thanks for the links. The intonation articles are particularly interesting. I think there is another factor to intonation other than the fact that fretting a note causes it to stretch and hence rise in pitch. There is also the fact that the actual vibrating length of a fretted string is a little bit longer than the distance between the fret and the bridge because of the height of the bridge. So if you have a string of length L and height (action) d fretted at the 12th fret (L/2) the actual length of the vibrating string will be SQRT((L/2)^2 + d^2). Imagine the following scenario: Consider a string of mass M and length L. A small mass m is added near the bridge. When a note is fretted, the vibrating length is l. Let’s pretend for a moment (and I don’t believe this for one second) that the string vibrates at a fundamental frequency that is related l and the mass of the vibrating part (M/L * l) + m. Given that the effect of m becomes increasingly significant as l gets smaller, this would work to compensate for the fact that the intonation is increasingly “worse” the further up the neck you go. (Stands back and wait for the diatribe!) As for the elasticity, the string obviously deforms when it is plucked. If this deformation is not elastic then it is plastic and hence the string will not return to its original shape. This would mean that every time you plucked the string, it would need re-tuning. I know that there is some degree of plastic deformation over time (I think it's known as creep in metals) but I don't see how a string can loose elasticity and still be able to vibrate at all. I can see how the build-up of dirt and grease in the strings will affect the mass, mass distribution and flexibility of the strings. Also corrosion will affect the thickness and the action of the frets on the strings will also have an effect on the homogeneity of the strings.

Right, we're getting into the nitty-gritty here so the posts are going to be long! I'm not trying to be pedantic about the definitions of "elasticity" but when I get into science mode, I tend to try to be very precise about what I'm saying. Don't take it as a criticism, just me trying to clarify a few things. I think the two statements are different because "strings wear as they lose elasticity" implies (to me) that loss of elasticity causes wear where "string loose elasticity as they wear" implies that the wear causes the loss in elasticity. I'm not sure that I agree that strings "have" elasticity as a quantity that they can loose. It's late for me here so I'll try to explain a bit more in the morning.

@Fryovanni: Do you mean "strings wear as they lose elasticity" or do you mean "strings loose elasticisty as they wear"? What to you mean by loosing elasticity? I'm not proposing to fix an old string by adding some more mass to it. I'm suggesting that one might be able to avoid using a compensated bridge by instead compensating the new strings. I agree that winding things around a core will affect more than just the mass of the string but I doubt it would have very much effect on the strength of the string in the axial direction. What do you mean by "performance of the strings"? Do you mean their intonation or their ability to vibrate? @Wez: Interesting. I thought it would sound pretty bad if you had something like that!! Hoe much extra mass was there? You said about a cm's worth but how thick? was it just one extra wrap? That would be a lot more than the sort of extra thickness than I would propose to try.

ToneMonkey: I agree. I don't think it would be a good idea but consider this: A wound string has different thicknesses along its length because the winding has a round cross-section. If you cut a section along the length of the string it would look like this (excuse the asci art): 0000000000 <- winding -------------- <- core 0000000000 <- winding So the mass is less between the "0s" than it is in the middle of the Os. Now this variation in mass is on a length scale very much smaller than the length of the string so it will only have an effect in higher order harmonics but I suppose it's partly responsible for the destinctive sound of wound strings. Exam question: What length scale would a mass variation need to be over in order to significantly affect the fundamental frequency of the vibrating string? GregP: I like you use of the highly technical phrases "bunch of crap" and "messes crap up"!! I know can get treated strings but I'm not exactly sure what you mean by the string/tine area

Branched fromanother thread, we began a small chat about what would happen if you fiddled about with different thicknesses (mass) of string winding in different places along the same string. It was suggested to start a new topic to elaborate. One could easily affect the mass in different parts of the string by winding something (tape, wire) around the string or even soldering something on in a few places. As we have previously stated, there may not be any real reason why this would be helpful but I thought that I may be possible to compensate for intonation or to change the impedance match with the bridge/nut. I was asked to elaborate on those two ideas so here we go (bear in mind that I am not claiming to speak with any great authority here so feel free to correct any mistakes I make): Intonation: We know that, as strings age, the rust and other deposits on the string cause the intonation to change. Would it be possible to take a virgin string and add mass to certain parts of it in order to compensate for the nomal intonation problems that you get with guitars? This would be instead of moving the bridge saddles. How would this work? I'm not even sure that it would but I'll attempt to provide an argument in order to stimulate the debate. If a small amount of mass were added (or removed) from the part of the string over the pickups (ie so it's not in the fretted part), this mass would have an increasingly significant effect on the vibrating part of the string it were fretted higher up the neck. This would be becasuse the added mass would be increasingly large relative to the vibrating part of the string. As such it might be able to compensate for the intonation. Impedance: A string/bridge interaction could be thought of as a string (of relatively small mass per unit length [MPUL]) joined to a string of very large MPUL. This provides a jump discontinuity in the impedance and waves are reflected back along the thin string with a small amount being transmitted to the thick string (bridge). The amound of energy transmitted is dependant on the impedance change and the wave frequency (lower pitches are transmitted better). If one were to take a short section of the string before the bridge and continuously increase the MPUL up to the bridge, the impedance change would be less of a jump and hence the way the waves would be transmitted would be different. Perhaps it could be done in such a way as to transmit more energy to the bridge (and hence sound board) at the expence of sustain. Sorry for the long and rambling post (you didn't have to read it if you didn't want to!)

I can think of two possible reasons why one MIGHT want to experiment with different mass distributions along a string (but I'm not sure how much they would work): To compensate for intonation (but you'd have to custom make each string for the guitar in question and I'm not even sure it would work anyway By having the last cm or so of the sting (near the bridge) having continuously increasing mass, you would create less of an impedance mismatch at the bridge (although this would probably allow more energy to be absorbed by the bridge and hence reduce sustain) Just some wacky ideas, like you say it's a bit of a crazy thing to do. If you vary the mass over the whole string, I doubt you'd even get a sinusoidal looking waveform on the string. I suppose that different pickup positions might end up "hearing" different pitches. Anyway, sorry if I've gone a bit off topic, I'll shut up now.

I'm not sure what you mean by binding the string. If you mean wrapping stuff around it then this will increase the mass per length of string but the binding will not be particularly in tension (it's only the core of a wound sting that's load bearing as I understand it) and so will not affect the tension of the string (except that the whole string will need to be a bit tighter to get it up to pitch). Binding the sting with different mass per unit length as you move along the string (ie thicker binding at the bridge end) would affect the formation of the standing waves on the string when it was plucked. I think this would be pretty weird and hard to tune/get the intonation right.

Well, it would have to be the bridge humbucker and the middle single coil. It's got the usual Ibanez 5 position selector and in the neck + single position, I can hear the single coil dropping in and out of the mix. It's only the neck humbucker that consistantly has a good connection.