[pianotech] Mysterious Key Noise

[Ron Nossaman]

Patrick C. Poulson wrote:
> 
> Greetings: I am working on a grand piano that has a noise coming from C2 
> that is eluding me. The symptom is a knocking that occurs on the 
> downstroke. The noise disappears when the sustain pedal is depressed, 
> but still present when the C2 damper is lifted individually. I initially
> thought it was the key end felt, but the fact that the noise remained 
> when I lifted the damper manually excluded that as the source. 

Right, and it also excluded damper leads, flanges, springs, 
and up stop rail for similar reasons. It also excludes the 
wippen, since the noise disappears with the pedal depressed, 
but not with the damper lifted. What's left is what Dave 
Porritt suggested as the likely cause. The key end hitting the 
damper tray.

Ron N