Monday, January 20, 2014

Cat urine vs. Digital Piano, Round 2

Formerly-Feral-Fergus peed into my digital piano before settling down into his new home.

Round one was adjudicated as being won by the cat pee because the rubber-boot key contacts would not sit straight when the circuit board was slid over them from the end of the action.

You can see pee-induced corrosion and the way that the boots are not all happily slotted-in.  They have to be un-stressed in order to move freely.
This shows the skews caused by trying to slide the tight-fitting circuit-board under the rubber boots.  The boots are molded in long strips.   There are three sections in the bass half of the keyboard.  The contacts are graphite that is somehow applied to the bottom of the dents of the boots.  Strike force is calculated by measuring the time between two switch events.  If you look closely you can see two dents in each boot.

This instrument has a great deal of spill resistance in that the switching is capacitive and not based on making electrical contact.  If it weren't for the fact that the urine crystalized, I think there would have been no problem.   It still worked while it was wet.

I put one of the hammers on top of the keybed so you can see it.  The hammers strike up through the slots from below and pass into the body of the key.  They don't actually strike the keytop, though.

If you look carefully at the hammers, you'll see a round opening with a bushing.  That's completely unused in this instrument.  At first I thought it was a feature for a different action using these same hammers, but after removing most of them manually, I've figured it out.  That bushing takes a rod.  The rod is a tool that allow you to install or remove a bunch, maybe all, of the bushings in one operation.

Wish me luck.  I like this instrument.  It's a GEM (General Music, Italy) PRP-800.  The GEM instruments had something to them that I can only call a traditional Italian craftsmanship.  They didn't have a lot of glitzy features, and they didn't compete on technical specifications.  They just have a musicality and responsiveness that's often lacking in sample-based instruments.

1 comment:

  1. hope you get it fixed. Cat Fricazzi on the menu?