Check out the sustain, especially for E4, E5, and E6 coming from the Korina-KorinaCocobolo setup shown in purple.  What you have here is more than 3 times the sustain added to the E note compared the original Swamp Ash-MapleMaple build.  You all know what added sustain does – there is so much more hang time to the note or chord that the guitar seems to play itself.  Add to this the increased color in the higher regions of the frequency spectra and you can imagine how this Korina-KorinaCocobolo build with the JB pickup works out to be a more robust and dynamic instrument compared to the “traditional” Ash-MapleMaple build.

 Well that’s just the picture for the open E note but you may ask what about the other strings and notes.  The answer is they will respond differently but in an overall similar manner.  What about different pieces of like wood?  These may have a totally different response.  That is why one guitar can play so much different than a like one (baring of course poor construction or setup issues).  One thing for certain is that the pickups set the tone – and every piece of wood has an optimum pickup. What makes CFCG most unique is that the pickups used in each build are never pre-determined. First we decide on the woods and the playability features of the instrument (body wood, neck wood and profile, fingerboard wood and radius, fret size and material). Then the guitar is built and tested in raw wood form. Our UBR
TM design accommodates all humbucker and Strat sized pickups. The guitar pickups and all electronics are mounted on an easy-to-remove prewired pickguard assembly which connects to the guitar body using a simple power plug. This makes changing the guitar electronics as simple as removing the pickguard screws and swapping out one pickguard assembly for another. Interchangeable electronics allow us to search for and find that perfect tone on every instrument. We build each instrument with the unique response of the woods and pickups in mind right up front. This test work takes a little extra effort on our part, but this is actually the fun part of the process. Finally we decide on the nitrocellulose lacquer and hardware finish, and other appointments to make them look cool as hell. These are the guitars that travel with us to shows and are available for you to play and purchase at a number of regional stores.


It’s too bad, but I had other plans for this Korina body – so I eventually went back to the Swamp Ash body with the Korina-Cocobolo neck for the final build. 


           Now this one’s a player….                                                                                         Not a bad alternative Korina build either!

Woods & Pickups:


Do woods make any difference in the sound from solid body electric guitars?  I get asked this question all the time.  Probably because I like to build instruments using some of the more exotic wood types as well as the more traditional woods.  What I would like to do to answer this question is to show one example of how you can go about changing the gain (or amplitude) and the tone (or color) in the output of a solid body electric guitar as well as adding increased sustain to the instrument by choosing the pickups and wood types used in the guitars construction.

First let me establish a few definitions on how the data will be presented here.  The audible frequency range is 20 Hz to 20,000 Hz (or 20 kHz).  I will be concerned here with frequencies between 250 Hz and 10 kHz.  The amplitudes of the measured data are presented in dB’s (decibels).  A way I put common sense to this unit of measure is that, to your ears, if you think the volume of sound is “half as loud” you would measure a -10 dB loss in amplitude.  Half of half as loud is -20 dB, etc.  In order to save time and space here I will provide more detailed write-ups upon request where I have already defined the guitar setup, data collection method and accuracy, and other technical stuff that you might need to understand what I am talking about in this paper. 
Just keep in mind that the same hardware, setup, and electronics are used in each test (except for the neck and body pieces) and that the differences in the spectra are not the results of picking differences because of the methods I use to calibrate and sample the data.  The sustain measurements are essentially independent of how I pick the strings (write info@calaverasfretworks.com to request more details).

To simplify the discussion and data presentation in this article I will only be talking about measurements of the fat open E string (or 6th string).  This is in no way the complete picture of what is going on, but it will give the reader the basic idea of how complex the total picture can be.  The harmonics of the E note on the guitar are shown in the table below.

What happens if I now keep the JB pickup and the Korina-Cocobolo neck and replace the Swamp Ash body with a Korina one?  Check this out – more color added for frequencies above 4 kHz or so.  The open E note from the Korina body guitar (shown in green) is even brighter still!

The spectrographs shown in this article are plots of gain (sound amplitude in dB) versus frequency (in Hz) over much of the audible spectrum.  The data peaks that you see in these spectra include the harmonics of the E note along with other frequency resonances that occur in the instant right after the string has been plucked.

I have designed the Calaveras Fretworks Custom Guitar to be completely modular and all of the parts are easily interchangeable.  All of the electronic and hardware components (pots, switches, caps, bridge, nut, tuners, screws…) are identical.  The pickups and all electronics are mounted on an interchangeable pickguard assembly that can be swapped out between guitars in a matter of minutes.  The ability to easily swap out pickups is a powerfull design tool and what makes the CFCG the most versatile guitars on the market today.

Taking a look at the differences between two pickups mounted into the same guitar configuration (same wood and hardware) would be the obvious place to begin.  By far the pickups make the most significant contribution to the sound of the solid body electric guitar - you buy the pickup and you buy the sound.  The spectra shown in gray is taken of the open E string from a Swamp Ash body guitar with a two piece Maple neck using a Fender Texas Special bridge pickup. The spectra shown in purple is from the same guitar this time with a Seymour Duncan JB pickup at the bridge position.  This is where it is great having interchangeable pickguards because this pickup swap takes me about 10 minutes.  No surprise here that the JB produces much higher amplitudes for frequencies up to about 1.2 kHz or so.  For most of the frequency range above that the Texas Special produces an equivalent or sometimes even higher frequency response to that of the JB.  In other words, for the open E string, the JB pickup produces an E note with a fatter bottom end while the Texas Special dominates the mid and high end response albeit with an overall lower output (volume).

But you may ask is this all the wood does for you is add attack and make the E note brighter?  Well, no.  These spectra don’t tell the whole story.  Keep in mind that we are looking at plots of the output of the guitar pickup immediately after the note has been picked.  What happens over time is even more important to your ears and to the way a guitar actually plays.  As time goes on after the pick the amplitudes will decrease until each of the resonance peaks collapse into the background noise of the electronics.  I can use what I will refer to as “narrow band” sustain measurements to answer the question, “How much time will it take for the amplitude of any particular frequency component to reach a certain dB level of loss after a note is picked?”.  For example, if I want to consider the E4 harmonic I can look at a narrow frequency band centered around 330 Hz and use the spectrometer software to calculate the time it took for that harmonic to degrade -20 dB after the E note was picked.  The answer may be, let’s say, 2.4 seconds and I can then compare that sustain time to another sustain time from, say a different pickup or wood type.  The graph below summarizes the narrow band sustain results for the major harmonic components of the E note for the three different wood types we have looked at here.

Click the button below to open a PDF of this article.

Now let’s keep the JB pickup on the Swamp Ash body and just change the Maple neck to a Korina neck with a Cocobolo fingerboard.  This is a gorgeous wood combination with more than looks to offer.  Check out the tone (color) that is added to the sound of the E note for frequencies above 3 kHz or so.  The E note with the addition of the Korina-Cocobola neck (shown in orange) is brighter.  The reader should keep in mind here that one tick on these graphs (10 dB) sounds like a gain of twice as much to your ears, so these are significant changes.  What I found is that the subtle amplitude (gain) variations that occur in different regions of the frequency spectrum are unique to a particular neck and/or body wood type and therefore color the way a particular note sounds for any given pickup.  The pickup is the major contributor to the overall sound of the instrument and the woods add color.  You can hear it and you can also measure it.