String buzz

[Ed Sutton]

Jeff-
Why not just trim the lever?  Or does this sound too much like The Old Piano
Hospital approach?
Ed S.

----- Original Message -----
From: "Jeff Tanner" <jtanner@mozart.sc.edu>
To: "College and University Technicians" <caut@ptg.org>
Sent: Thursday, June 05, 2003 10:23 AM
Subject: String buzz


> Hi all,
> I ran into a problem yesterday I've never seen before.  The piano: Yamaha,
> I'm guessing P2 (I don't think it's a P202, but I don't see a model
> number).  When the damper pedal is pressed, E20 buzzes on the C#29 damper
> lever (2nd into the bass section) on a fortissimo blow.  My temporary
> remedy was to bend the damper stop rail towards the damper levers in that
> section and reduce pedal lift by adjusting the pedal to the point the
> buzzing stopped.  But there's a lot of pedal movement now before the pedal
> rod contacts the damper levers, and not much lift at the bottom.  So, the
> pedal feels "squishy" now.
>
> Here's the "pre-temporary-remedy scenario":
> Part of the damper lift problem is in the pedal lift, with the treble
> dampers lifting gradually ahead of the bass, so that it takes more pedal
to
> lift the bass dampers.  Still it's not a lot of difference, and I'm
> thinking that even with even damper lift, you're gonna get the buzz still.
> The damper lever felt shows no sign of wear, either from the rod or the
> spoon, which I find amazing for a 30 year old piano.  Spoons are
contacting
> the damper levers perhaps a little early in the travel, but I don't see
the
> relationship there at first glance.  But even with early spoon contact,
the
> pedal lift exceeds spoon lift.  Damper lift is too good to start over with
> a complete wire bending, spoon adjusting regulation.  The only real
problem
> with the damper lift is the slight gradual delay from treble to bass.  I
> can pull the damper lift rods and bend the hinges to even the damper lift,
> replace the felts around the pedal to reduce pedal travel, but I'm not
sure
> that will cure the buzz.
>
> Here's the fun part.  The owner told me that the buzz goes away during the
> winter, which tells me there must be a lot of movement in the bridge due
to
> seasonal changes.  (My Dampp-Chaser hygrometer measured 64% RH yesterday)
> He said it hadn't always done it, but has been doing it for a while now.
> Maybe he'd just not noticed it in the piano's early days.  Somebody has
> told him he's got a cracked soundboard and this was producing the buzz,
but
> I didn't see any visible cracks - at least not below keybed level -- and
> that's not what's causing the buzz anyway.  This one damper/string buzz is
> the only one doing it.  This damper moves exactly the same distance as its
> neighbors, and I don't see that the string level on E20 is any different
> than its neighbors.
>
> I recommended a Dampp-Chaser system, but he kind of balked at the idea of
> the complete system when I told him what it costs.  The back side system
is
> a little pricey for a piano he said he paid $900 for new.  He might go for
> a dehumidifier partial system, which might make enough difference in
> soundboard movement to eliminate the problem.  But I still don't
understand
> why it is only this one damper lever/string combination which is doing it,
> when I see no visible differences between it and its neighbors.
>
> Any ideas?
>
> Thanks for listening, and sorry it took me so many characters to lay out
> the problem.
>
> Jeff
>
>
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