Under the Hood: Robot Guitar embeds autotuning

Tag: DC Reduction Motor

Gibson Guitar has been an aggressive technology adopter. On the heels of its Ethernet Out (digital) guitar, the company has released the Robot Guitar, which automatically tunes to a range of standard and alternative tunings at the touch of a button.

Gibson is the public face behind the Robot Guitar, but German company Tronical and guitarist and EE Chris Adams are the inventive forces. Tronical developed the automation as a guitar retrofit kit back in 2006, and Gibson licensed the technology to launch the original, limited-run Robot Guitar in December 2007. Other Gibson models are following that launch to market.


Electromechanics join with embedded processing to produce an electric guitar that takes over the often laborious task of tuning and retuning. Aside from simplifying life for tin ears and those who would rather play than tune, the design is useful for players who require both standard and "open" tunings. By supporting quick transitions among tunings, the Robot eliminates the need for multiple instruments (one for each tuning) and the cost that goes with them.


At the core is a standard Gibson Les Paul electric guitar. The departures from a stock guitar begin with a special bridge and tailpiece. The bridge provides one of the two endpoints that set the string length; the other string endpoint is the "nut" at the end of the fret board. The bridge has the usual individually adjustable "saddles" for each string, which adjust the intonation of the guitar. Unlike a standard bridge, however, the saddle pieces (normally metal) are replaced with isolated piezoelectric pickups to detect the string frequency. Audio output comes from a separate pair of wound pickups no different from any other Les Paul guitar, thus maintaining traditional sound.


The piezo pickups, which detect string frequency, feed signals for each of the six strings from the saddle, by way of a flex circuit, through the guitar body. The flex terminates at the body electronics module, mounted in the position normally occupied by the volume control knob. Although the body electronics knob still serves as a volume control, the action begins when the knob is popped out to go into "Robot mode."