The after-boink

[slobone]

Hi, I have an Emerson upright that's almost 100 years old. On some of the keys, if I play them half-staccato and mf, you can distinctly hear the note sounding a second time as I lift my finger off the key. The effect is less noticeable if I play more detached or less detached, or louder or softer.

As far as I know, none of the strings, felts, or rawhide parts have been replaced other than a few strings that I had to replace because they broke. Does anybody know what the cause of this after-echo could be?

[i heart xenakis]

For a moment there I thought this thread was going to be dirty

[bench warmer]

Take a look here; much easier than my trying to explain it without a diagram.

https://www.balaams-ass.com/piano/dblblow.htm

Bottom Line: You need some regulation done on that piano.

[rachfan]

The after-boink is called a double strike of the hammer.   The problem is that the first strike sets the string to vibrating, while the second strike muffles the string vibration, thus spoiling the tone.  It can be caused by the let-off, the jack, the key tension spring, the back check or the key dip.  So each key that does it needs to be separately diagnosed, as there are five suspects rather than just one.  It also tends to be more frequent on uprights than grands.  Next time you arrange for your tuning, advise your tech that the piano will also need some regulation while he's there.  Good luck on that!