[pianotech] Hoffman 190 tuning instability

[Gerald Groot]

I had a Yamaha U3 upright with similar tuning difficulties and stability.
It tuned terrible and no way would it stay.  It crept continually.  I took
in another RPT for a 2nd opinion and we both agreed that there was too much
tension on the capo bar.  This was causing serious rendering problems making
it almost impossible to set the pin and keep the piano in tune for long
enough to leave.  Stings were creeping all over the place.  

 

We took some tension off from the capo bar in the tenor and treble sections
going very slowly, doing every other screw making sure everything was even
and that we weren't taking away to much tension.  Each time we gave the
screws a 1/4 turn, the pitch dropped by at least that much and more.  I
raised it back up each time so I could feel what it was doing at the same
time.  When we were satisfied with the proper angle of the strings coming up
from the capo bar to the speaking length of the wire and satisfied with how
it tuned, we quit.  It has tuned a lot better and has been stable ever
since.  

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of DAVID ABDALIAN
Sent: Thursday, August 27, 2009 11:34 AM
To: pianotech at ptg.org
Subject: [pianotech] Hoffman 190 tuning instability

 

I have a client with a Hoffman 190 manufactured in 2002, sold new in 2003
with tuning instability problems.   The piano has not stayed in tune since
the start.  It has Dampp-chasers complete six part system.   Multiple
experienced RPT's have tuned this piano since new.  The piano goes out of
tune in sections as would be expected with a gap between the pinblock and
the plate flange.  The gap is about .003 - .020 inch gap which is present
from note F1 - F2, from note E3 - C5 and from B5 - F8.  It is difficult to
tune also.  The strings don't seem to render well especially at the capo
bar.  Another RPT technician claims that it could be the Roslau wire also.
Any comments would be appreciated.

 

Regards,

 

David H. Abdalian, RPT



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