source file: m1439.txt
Date: Sun, 7 Jun 1998 12:40:51 +0100

Subject: Feiten fretting "intonation" patent

From: harmonic@globalnet.co.uk (Harmonics Inc.)

Having seen the claims and marketing nonsense for Buzz fretting (now available
with various guitars according to Harmony Central), I thought it was time
to have a look at the patent.
Here's what I found:
Method and apparatus for fully adjusting and intonating an acoustic
guitar
Inventors: Feiten; Howard B. (12501 Mitchell Ave., Los Angeles, CA
90066); Back; Gregory T. (16000 Sunset Blvd., #1, Pacific Palisades, CA
90272). Appl. No.: 896,685Filed: Jun. 10, 1992

A fully adjustable acoustic guitar bridge is claimed that allows the
strings (nylon or steel) of an acoustic guitar to be separately and
continuously intonated accurately and easily whenever necessary. The
bridge system employs a minimum of alterations to the traditional
non-adjustable acoustic guitar bridge to retain the acoustic qualities
of the instrument. Recessed, rear-loaded cap screws utilize the forward
pull of the guitar strings to stabilize the adjustable saddles. A
threaded saddle capture on each saddle provides stability, continuous
threading capability, and the freedom to use acoustically resonant
materials (bone, phenolic, composites, etc.) for saddles. These features
eliminate the need for springs or other fasteners, which would have a
negative effect on the acoustic guitar's tone and sustain. A rosewood
shim is employed on acoustic/electric guitars over the internal bridge
pickup. The vibration of the saddles on the shim is transmitted to the
pickup regardless if the saddles are located directly over the pickup or
not. The system has been tested and is compatible with most bridge
pickup systems that are currently on the market. The Rule of 3.3%, which
cuts 3/64" off of a guitar neck fingerboard (for a neck with a scale
length of 25.5") compensates for the various string tensions along the
neck to allow for any guitar, with an adjustable bridge and properly
located frets, to achieve accurate intonation at all fret positions.

If you want to refret for real microtonal use see:

http://www.ilhawaii.net/~lucy/lsd/frets.html