Friday I was called to repair an Ampico A grand, rebuilt about 20 years
ago.  I was able to get it to play rolls okay.

One problem I could not fix was a steady pitch vibration coming from
right behind the belly rail, just under the soundboard, centered left
to right (i.e. around note 44).  I was able to localize the sound but
not to identify the component that was vibrating.  It was behind the
stack and much higher up.  The noise was not being transmitted to
(amplified by) the soundboard.

It was not extremely loud, but definitely interfered with enjoying the
music.  I would estimate the pitch at between 60 and 120 Hz.  Can
anyone suggest things to look for?

Thanks,
Joseph Osborne
Carlisle, Pennsylvania, USA