User manual FISHMAN ADVANCED UNDERSADDLE PICKUP INSTALLATION

[. . . ] This article is intended to illuminate the finer points of fitting an under-the-saddle piezo pickup. The positioning of a piezo element on or within an instrument is a challenging installation problem. Necessarily, the pickup is extremely sensitive, and accordingly, its environment must fall within a small envelope to achieve full performance. Problems are not always what they first appear to be, but the mysteries WILL BE REVEALED to the perceptive. [. . . ] As a result of better force distribution between the saddle and bridge, the bridge will remain more stable, resist distortion and bending, and sound more solid. (Remember Objective II?) Top swivels and tilts (ideally a ball joint) to match interior angle of guitar top. Knurled collar to adjust vertical height of jack. Threaded to allow vertical adjustment. Even though it's more trouble and it ain't historic, etc. , we're convinced that it does really improve the pickup installation and often, the acoustic response. Further, it's not so much angle that it looks objectionable. As a bonus, this technique often helps us move the string take off point a little further back on the bridge, when needed to help correct "folding-up-sharp" intonation. Notched to clear back reinforcing strip. a - ROUTING A SLOT You will need a small plunge router to do the job. Make a base for the router with a 5-8° angle to achieve an angled slot. Make a routing jig to fit on top of the guitar. Cover the bottom of the jig with a cork or rubber gasket. The jig bottom should clamp to the guitar's edges only, and not tend to squeeze out the belly shape in the top, thus accommodate the aforementioned screw jack. The guide for the router base must fit precisely to avoid slop in the cut. Make adjustable endstops for to the length of the cut. A nice way to locate the existing slot is with an undersize pin chucked in the router. Dropped in the slot, the pin is a quick set up tool for slot angle and ends. 4) Figure 3 - JACK-Internal jack used to prevent movement of top during critical routing of saddle slot prior to pickup installation. 4. No end mill or router bit is capable of cutting a slot width identical to its diameter. All rotary cutters will shake, bounce on their own chips, etc. One way to beat this is to send a set of bits to your local cutter grinding shop. For a couple of dollars they will reduce the diameter of your standard 1/8" and 3/32" cutters by about . 010". These reduced cutters can be used first and followed by full size bits to kiss off the final few thousandths, resulting in a beautiful "wall" surface that will be very close to being "on size". In lieu of a reduced cutter, I like to use a 7/64" (. 109") two flute spiral end mill. Single flute bits will perform best in a router. There's lots of chip clearance, lots of positive rake to cut cleanly, and less tendency to bounce around in the slot full of chips. [. . . ] One common cause is a saddle that's binding in the slot. Be sure not to get too carried away when easing the fit between saddle and slot. Try for the closest slip fit that you can achieve. UNDER SADDLE PICKUP INSTALLATION . . . MECHANICAL FACTORS AFFECTING PICKUP PERFORMANCE a. [. . . ]