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<DIV><FONT face=Arial size=2>Ron, </FONT></DIV>
<DIV><FONT face=Arial size=2> Thanks for the =
straight info. I
only mentioned the SD-10 as perhaps being a little different because of =
the
steel insert capos. They are <U>really </U>different. </FONT></DIV>
<DIV><FONT face=Arial size=2> I forgot all about =
Jim Coleman's
glue trick. He told me about it and I guess I filed it in the wrong =
memory
module. I remember saying "That's neat, I can't wait to try it." I'm so
embarrassed.</FONT></DIV>
<DIV><FONT face=Arial size=2> Anyway, a lot of =
good info here,
Thanks.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>
<A title=sec@overspianos.com.au =
href="mailto:sec@overspianos.com.au">Overs
Pianos</A> </DIV>
<DIV style="FONT: 10pt arial"> </DIV>
<DIV>Susan's article was about an SD-10, but front duplex problems are =
the
same regardless of the manufacturer. There are pretty new pianos out =
there
which don't sound too pretty, with noises aplenty.</DIV>
<DIV><BR></DIV>
<DIV>Duplex bars which are:</DIV>
<DIV>* larger radius</DIV>
<DIV>* softer than the wire</DIV>
<DIV>* close to in-tune with a harmonic of the speaking length</DIV>
<DIV>* too long</DIV>
<DIV>are all factors which contribute to string noise.</DIV>
<DIV><BR></DIV>
<DIV>Ideally the front duplex should be:</DIV>
<DIV>* a small radius (these days we are setting to 1mm or slightly
less)</DIV>
<DIV>* harder than the wire (when rebuilding we harden the cast in =
bar)</DIV>
<DIV>* shorter, 40 mm is too long, under 30 is preferable though often =
impossible to achieve.</DIV>
<DIV>* set to a detuned length, ie. to a length mid way between two =
harmonic
lengths</DIV>
<DIV>* set to a height for a string approach angle of not greater than =
15
degrees (or the wire will be cut by the non-deforming small-radius =
duplex
bar).</DIV>
<DIV><BR></DIV>
<DIV>The 'glue on the duplex length' trick (thank you Jim Coleman =
snr), to
increase mass and therefore to detune, is a very effective on the road =
fix.</DIV>
<DIV><BR></DIV>
<DIV>We nickel plate our front duplex bars (after hardening) to =
improve string
rendering and to prevent corrosion.</DIV>
<DIV><BR></DIV>
<DIV>Ron O.</DIV>
<DIV><FONT face=Times color=#000000>-- <BR></FONT></DIV>
<DIV><FONT face=Times =
color=#000000> OVERS
PIANOS</FONT></DIV>
<DIV><FONT face=Times color=#000000>Grand piano =
manufacturers</FONT><FONT
color=#000000></FONT></DIV></BLOCKQUOTE></BODY></HTML>