Thanks for the replies. Yes, I was aware of the velocity curves and experimented with them. However they are very piano touch oriented, as they should be.
For us old guys who learned on something like the small spinet Baldwin OrgaSonic that I did with short staggered manuals, only one octave of bass pedals, rubbery key action with no sustain, decay or reverb whatsoever, we don't strike the keys. To avoid the annoying, choppy performance most piano players would produce, the focus of the few lessons I was given was to develop and refine the crawling, finger substitutions needed to progress smoothly across the keyboard of such an instrument. That is one reason I have been sought after to play organ for funerals, weddings, church services even though I was an electrical engineer (power and industrial control systems) to earn a living.
For pianos touch has three major components; down weight, up weight and friction – which is often
expressed as the difference between the up-down measured weights. Most pianists are happy when down weight is kept between 48 & 52 grams. This is the weight applied to the key at normal playing position that causes the key to slowly settle and lift the hammer to the strings. My P90 is very even across the keyboard but significantly high at around 56 grams to cause a key to settle and cypher the note.
Another major component of touch is inertia, hence the idea of a “weighted keyboard”. If you are interested in all this, go to the “piano world” forum. This subject has been discussed there several times ad-” infinitum amongst several high-end designers and rebuilders.
Regarding the P90, there is no adjust-ability. Likewise there should be no change over a long rigorous service life. There is a way to reduce up/down weights to decrease “touch” at the expense of adding inertia. Since the keys are largely hollow, standard lead piano key weights could be glued into the keys using something like automotive “trim/weather stripping” cement. Almost every acoustic piano has lead slugs set into each key. I've obtained several “for the hauling” derelicts, both upright and grands, and rendered them for parts. I'm sure there are more than enough lead weights for my P90.
I'll keep you informed should I decide to commit to making this mod.
Loren
PS I inadvertently hit the reply button before finishing the previous post. Sorry!