The Idea: I play mostly solo jazz chord melody for the last number of years with both archtop and flat top guitars. Loving sonic aspects of each style of guitar, I have always wondered what a maple carved back; acoustic flat top guitar would sound like. I knew that a number of companies (Eastman, SCGC etc.) and luthiers (Blanchard, Buscarino etc.) have made flat tops with carved backs, so it had been done before (earlier Epiphones and Guilds were arched, laminated backs I believe). I was hoping the result would be a guitar with some warmth, sustain and overtones of a flat top guitar together with the punch and projection characteristics of an archtop guitar. Last year, I commissioned a Bigleaf Maple/German Spruce guitar with California luthier, Bruce Sexauer. Bruce was the ideal choice given his experience in making both types of guitars and I had worked with Bruce before and he had previously built me a guitar which I adored. Since Bruce really doesnt have specific models but uses codes for describing combinations of style, size, scale length features. Bruce refers archtop guitars he refers to as "JZ" and his flat top models as FT. Bruce also calls his multi-scale guitars "JB" and when he began to offer a smaller scale offset, he called it "JB/2". So when conceiving this guitar, we decided to call it a "JZ/2" because it was only 1/2 carved (no carved top). The "15" refers to the number of inches across the lower bout and the "C" is for cutaway. Being sort of a hybrid guitar, I wanted this guitar stylistically to pay a bit of homage to the historic flat top designs from Nazareth, but also pay a nod the classic archtop guitars of Kalamazoo as well. So design elements such as the ebony pyramid bridge, abalone diamond and square fingerboard inlays, and a trapezoid shaped peghead are some nods to Nazareth. Whereas the guitars finish, its carved maple back and headplate pendant are nods to Kalamazoo. The choice of finish was special as well. We wanted to visually enhance the flamed curl in the maple, but not obscure any of its beauty with any opacity of a sunburst. Bruce makes a variety of stringed instruments including violins. He used a historic tinting technique (I am sworn to secrecy!) to enhance the flame in the maple and to tie the hue of the mahogany neck together with the body. For the top, Bruce used the tinting in his traditional oil varnish to create a subtle fade that was darker towards the rims to add a sense of dimensionality. The Decisions: The Sexauer / 15 thread in the AGF Custom Shop (http://www.acousticguitarforum.com/forums/showthread.php?t=370542) documents its construction. Bruce needed to make a number of design decisions when making it because all of the parts of a guitar work together acoustically. For the JZ/2 In creating the top, Bruce chose mostly based on luthiers instinct to leave the German Spruce a bit thicker but to aggressively carve the braces shallow. A typical 000/OM is 3-1/4 at the neck and 4-1/8 at the end block. A flat backed guitar has a relatively shallow arch. I believe Bruce would typically use about 18 radius which a lower bout section has about 1.30 in2 in volume (without the addition of ladder braces!). The JZ/2, having an arched carved back adds additional interior volume to the body. If you calculate a back with a ½ height created by a 4-8-1/2 radius across the widest part of the lower bout the section has 5.00 in2 in volume (about 5x when you consider no ladder braces). So the guitar was going to have additional volume. To adjust for this; Bruce reduced the rim depth by about 1/8 to compensate for the added back volume of the arch. Bruce also regards the backs of his guitars as active participants in creating the sound and to this end; his backs are typically built quite thin. When reducing the back radius you also add stiffness for a given thickness. Bruce strived to use a relatively shallow arch and thin carve to minimize this effect. After the box was assembled and the binding was on he continued to scrape the back particularly near the rims in the recurve area until it tapped to his liking. The Guitar: The guitar is 000 in size (15 at the lower bout); has a 24.9scale; 14-frets to the body and a 1-3/4 nut, 2-5/16 at the saddle. Bruce used a beautiful set of Old German Spruce for the top that he sourced from EuroSpruce purveyor Martin Guhl. The Bigleaf Maple billets had been seasoning in his shop since the late 1990s. We chose a backset with some curl that could be bias downward towards the lower bout to create a chevron pattern. The traditionally designed rosette contains both Maple and Green Abalone. The headplate veneer, backstrap, endgraft and binding are made from a contrasting, figured Bocote. The purfings made by Bruce are Pernambuco to add a color highlight with Green Abalone added to the top purfling. The headplate veneer became an area of collaborative creativity between Bruce and I. I came up with Charles Rennie MacKintosh style typography of Bruces name SEXAUER and Bruce figured a way to cut the MOP into Ebony for the nameplate (the much harder job!). Bruce also developed a stylized Ebony/Maple/Pernambuco torch pendant that played homage to the art deco designs seen in vintage archtop guitars to visually balance the headplate. We put a set of 18:1 Schaller Grandtunes in Vintage Copper with Snakewood buttons. The Sound: Sound is something that is always extremely difficult to describe (also to record). There are four dimensions of sound of a guitar that I will do my best to describe for you. I thought instead of describing things in absolutes, I would compare it to a flat backed guitar, made from a dense, glassy tropical hardwood, close in size made by the same builder (Pernambuco/German Spruce L00). The JZ/2 is slightly wider in its lower bout, but shallower in depth than the L00. I think this comparison is a good one, particularly with all the blanket descriptions of what a maple guitar "sounds like" stereotypes you see put out there. I will try to put up some short videos (unfortunately using my iPad) perhaps contrasting the two guitars by playing the same piece. In the meantime here are two clips that Bruce laid down: JZ/2 http://mojoluthier.com/Music/JZ2-OhBaby.mp3 L00 http://mojoluthier.com/Music/242.mp3 Responsiveness: By responsiveness I mean how much the volume of the guitar increases as the dynamics of my picking attack increases and how full the sound is with a gentle touch. The JZ/2 is responsive, but not as responsive as my L00. Headroom: By headroom, I am talking about how loud it can get without beginning to sound distorted when I really dig in. As a reference of high headroom, I use a BRW/Red Spruce OM that I used to own. The JZ/2 has tremendous power, surpassing my L00. Balance: By balance I am talking about the relative volume between the strings across the neck "open" and at positions up the neck of the guitar. Since I play many chords where strings are either pinched or arpeggiated, a balance in volume between the Low E, A, D with the B and high E strings. Many tunes connect chords by bass line movement is established on the E, A and D while melody is played on E, B or G, so balance in volume is desired. I play chords up and down the neck as well. Like the L00, the JZ/2 is completely balanced in its volume in all registers. Fundamental/Overtones: This is a somewhat of a subjective way of speaking about the relative harmonic content of the timbre of the guitar (sometime referred to as dry or wet). I like the timbre to not be "dry" (like vintage Martin) nor awash in overtones either (wet like a Goodall). The L00 is certainly more awash with overtones, but the JZ/2 while leaning a bit dryer presents a descent amount of harmonic overtones. Attack/Sustain: By this I mean how fast the sound develops post pick (attack) and how long the sound (fundamental and overtone) takes to decay (sustain). I play a bunch of ballads and standards mostly in a moderate tempo (no Giant Steps at >300 bpm!). Notes develop much faster out of the JZ/2 than my L00. Both guitars have lots of sustain which surprised me a bit. Summary: The JZ/2 is a fairly dynamic instrument with tremendous headroom. I think these two attributes trade-off with each other. Like all instruments Bruce makes, it possesses balanced volume across the strings and in all registers. It leans towards the "dryer" side of the tonal spectrum but still rings with plenty of overtones. It has a very fast attack with sound developing very quickly which provides an impression of "thickness" to its timbre, particularly in the trebles. It has a surprising amount of sustain in both the fundamentals and overtones. It is a superlative guitar in concept and execution. Bruce simply knocked it out of the park with this guitar. It is an excellent contrast to my L00 in that the JZ/2 excels in headroom, speed and an overall "fat" timbre to the L00 which excels in responsiveness, choral overtones and sustain. Mucho Kudos to Bruce!