The Edge Zero II is a double locking tremolo system developed for Ibanez and offered on a number of Ibanez guitar models. It was revealed in December 2010 and introduced on guitars available in 2011. It is produced in China.
The Edge Zero II is a less expensive version of the Edge Zero, on which the design is based. The Edge Zero II is used in mid-tier guitar models, replacing the Edge III as the most common double locking tremolo offered on guitars produced outside of Japan.
The Edge Zero II consists of a base plate cast of a zinc-based alloy (likely Zamak) with individual saddles and fine tuners. This body is attached to a dense cast metal block connected to a set of three springs which balance the tension of the guitar strings and allow the tremolo to float in a cavity routed into the guitar body.
Like all double locking tremolos, the Edge Zero II is designed to be use with a locking nut which anchors the strings at the headstock. Fine tuners attached to each saddle allow the player to adjust tuning once the nut is locked down. The saddles can be moved fore and aft to set intonation of each string. The entire bridge can be adjusted up and down in the cavity to adjust the string action by raising or lowering the studs. There is no allowance for adjusting the height of individual strings. Instead the base plate is built in a way so that the saddle heights match the radius of the fretboard.
The Edge Zero II shares the locking stud posts of the Edge Zero. The posts feature an internal grub screw which can be locked down against the bottom of the stud insert. This design provides an additional measure of tuning stability by increasing the stability of the studs.
The Edge Zero II lacks the Edge Zero's built-in intonation tool. Setting correct intonation without this tool is a more tedious process.
Zero Point System
The Edge Zero II is offered in varieties with or without the ZPS3Fe counter-tension tuning stabilizer system.
The ZPS3Fe is a system of two additional springs connected with a linkage which are positioned in opposition to the main tremolo springs. These springs help to ensure tuning stability by returning the tremolo more quickly and accurately to the neutral position when the tremolo arm is released. The system is also intended to help maintain tuning stability when bending strings (particularly on double stop bends) and facilitate simpler set-up of the tremolo and easier string changes. In addition, it is touted with an ability to maintain the tune of the remaining strings should a user break one string while playing; it seems that while the ZPS helps somewhat in this situation, this claim is largely overblown.
The ZPS3Fe gives the Edge Zero II a somewhat stiffer feel than the earlier Edge designs. This stiffness manifests only when pushing down on the bar; pull up is not effected since you are only countering the tension of the two normal strings. Since the ZPS hastens the tremolo's return to the neutral point, it limits the amount of "flutter" when releasing the trem. The ZPS can be quickly and easily removed, should the player desire a more traditional feel.
Versions of the Edge Zero II for seven string guitars (referred to as the Edge Zero II-7) and for left-handed guitars have been produced. A version with a 240mm radius baseplate is made for Joe Satriani's signature JS140. The version made for the RGD series includes a set of springs from the seven string model in addition to the normal six string springs.
US patent dispute
The Edge Zero II was was licensed under agreement with US Patent holder Geoffrey McCabe since 2007 -- none the less, the product was largely removed from the US market in 2014 along with other trems which featured the Zero Position System not because of patent claims related to that design. The technology was later returned to the US under continuing license of McCabe applicable patent and continues into 2020....
- Adjustment instructions (PDF)