The Edge tremolo is a double locking tremolo bridge developed and manufactured by Gotoh for Ibanez. It is sometimes referred to as the "Original Edge" to differentiate it from the various versions that have been released since. The Edge is acclaimed by many guitarists as the finest trem system available in the market. It was introduced in 1986, discontinued in 2003 and brought back in 2010.
The Edge is based on the original, patented Floyd Rose tremolo design which Ibanez & Gotoh licensed. As such it incorporates a double locking design, meaning that the strings are retained at both the bridge and the nut. By effectively minimizing the length of string the Floyd Rose design allows players to perform crazy manipulations of the tremolo while enabling the guitar to return to tune when the tremolo was released. Fine tuners on the bridge facilitate tuning without unlocking the nut. As with the traditional Fender-style synchronized tremolos which came before, the Floyd Rose used a set of springs and an adjustable claw located under the guitar body to equalize the tension of the strings and allow the tremolo to float. A set of six saddles which can be moved independently forward or backward to achieve intonation retain the strings at the bridge. Meanwhile the Top-Lok III locking nut pairs with the Edge to secure the strings at the headstock.
Key improvements of the Edge design over the original Floyd Rose include replaceable knife edges, a less bulky saddle with fewer sharp edges, more overall mass (to increase sustain), steel sleeves in which to mount the anchor studs and a pop-in arm. The bass and treble side pivots are different shapes to minimize side-to-side movement. The body of the tremolo is produced using lost-wax casting which allows the use of a denser metal to maximize harmonics and sustain. The fine tuners on the Edge are positioned well back on the rear of the unit to prevent interference when employing muting techniques with the strumming hand. The Edge's pop-in tremolo arm is secured by a spring and friction to prevent the bar from rotating is provided by nylon bushings that need to be occasionally replaced.
When it was introduced for 1986 on certain Pro Line and Artist series models the Edge was surface mounted on the guitar top. However with the introduction in mid-1987 of the JEM777 and RG550 a cavity was routed in the body below the tremolo to allow the player to manipulate the tremolo either by pushing down (to lower the pitch) or pulling up (to raise the pitch). Also added in 1987 were locking studs (small grub screws installed inside the pivot anchors which prevent movement when screwed down) and a retainer to prevent the springs from slipping off the tremolo block.
The overall height of the Edge tremolo in the cavity can be adjusted by raising or lowering the height of the studs. The height of the individual saddles is not adjustable, but the radius of the base plate matches the 430mm (17") radius of the fretboard on the Wizard neck. A version of the Edge made for the Joe Satriani series guitars has a baseplate with a radius of 270mm (10 5/8").
Although the knife edges of the Edge were designed to be replaceable, Ibanez (nor Gotoh) has never actually offered replacement parts. Even so, the Edge has proven quite durable, and there has been little outcry from the guitar community for knife edge replacements.
The Edge was paired in 1986 on some high end models with the Back Stop stabilizer, however the Back Stop was short lived, disappearing after 1987.
Various derivatives of the Edge have been created since its introduction in 1986. Ibanez released a single locking version of the Edge in 1988 as the Edge II which eliminated the locking nut and thus the necessity for fine tuners. The Edge II was used on only a couple of models, most notably Vinnie Moore's signature VM1. A seven string version of the Edge was introduced in 1990 for Steve Vai's new Universe models.
In 1991, Ibanez introduced the Lo-Pro Edge, a lower profile version with the fine tuners moved to the back of the saddles and separated from the string locks. Although the Lo-Pro Edge replaced the Edge as the flagship tremolo in 1991, Ibanez continued to use the original Edge on certain models, for example the 1997–2002 RG550 and RG570 models. A seven string version of the Lo-Pro Edge completely replaced the Edge 7.
Both the Edge and Lo-Pro Edge tremolos were discontinued in 2003 in favor of the new, low-profile Edge Pro tremolo. The Edge Pro proved to be unpopular with a segment of the market since its design eschewed the Edge's locking studs and thus it didn't provide the same legendary tuning stability. In response to the somewhat tepid embrace of the Edge Pro, the original Edge and Lo-Pro Edge were reintroduced in 2010 and the Edge Pro was discontinued.