Hello,

I want to purchase a Yamaha digital piano. While researching, came across several different terminologies for the key action, but I could not find what the difference is between them. My question is what is the difference between:

- Graded hammer standard
- Graded hammer action
- Graded hammer effect
- Graded hammer system
- Soft touch action
- Graded soft touch action

I suspect some of them are the same, but I really don't know

Thanks

A few years back the issue of weighting digital actions differently in zones to more accurately approximate the keyresponse to an acoustic grand. Acoustic piano hammers are large in the bass and narrow to very small in the trebble. The use of the term "graded" in any phrase referring to the action of the digital refers to this.
As a piano technician I could care less what that call it or what materials they use, or what designs they use to accomplish it. All I care about is how it feels related to a quality acoustic grand.

actually, there're only 4 types (excluding no-weight/semi-weight keyboards):

GHS = graded hammer standard
GH = graded hammer/graded hammer effect/graded hammer system
GH3 = graded hammer generation 3
NW = natural wood action

Don't pay attention to the terminology.
Play as many different models as you can and when you come across one that feels and sounds good,get it.

The differences in the keyboards on the Yamahas are discussed here:

http://music.yamaha.com/products/highlights/keyboardsAST/8.html