<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD><TITLE>Re: Short Treble (sustain?)</TITLE> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <STYLE type=text/css>BLOCKQUOTE { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } DL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } UL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } OL { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } LI { PADDING-BOTTOM: 0px; PADDING-TOP: 0px } </STYLE> <META content="MSHTML 6.00.2800.1264" name=GENERATOR></HEAD> <BODY bgColor=#ffffff> <DIV><FONT face=Arial size=2>Hello Ron Overs</FONT></DIV> <DIV><FONT face=Arial size=2>Why not see what response your = observations get from Grotrian-Steinweg themselves? Do you mean Model 220? Or should it = be Model 225? I have a superb 225 on my rounds and have been corresponding with = Grotrian on the subject of a 10 year service/regulation. They have been most = helpful. Write to: Burkhard Kaemmerling at: <A href="mailto:kaemmerling@grotrian.de">kaemmerling@grotrian.de</A> = </FONT></DIV> <DIV><FONT face=Arial size=2>Regards</FONT></DIV> <DIV><FONT face=Arial size=2>Michael G (UK)</FONT></DIV> <DIV style="FONT: 10pt arial">----- Original Message ----- <DIV style="BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A title=sec@overspianos.com.au = href="mailto:sec@overspianos.com.au">Overs Pianos</A> </DIV> <DIV><B>To:</B> <A title=pianotech@ptg.org href="mailto:pianotech@ptg.org">Pianotech</A> </DIV> <DIV><B>Cc:</B> <A title=alfailsa@accsoft.com.au href="mailto:alfailsa@accsoft.com.au">Alf Reichardt</A> </DIV> <DIV><B>Sent:</B> Monday, November 03, 2003 10:21 PM</DIV> <DIV><B>Subject:</B> Re: Short Treble (sustain?)</DIV></DIV> <DIV><BR></DIV> <DIV>Del, Ron N. and all,</DIV> <DIV><BR></DIV> <DIV>The string buzzing on the side of the agraffe slot is most = certainly the problem. Earlier in my career I recapped the failed bridges on a = Grotrian 220. Since the owner was travelling to Germany on business, when he visited = the factory they sold him a replacement treble bridge cap. Unfortunately, = the new bridge cap was afflicted with the same 'disease' which was common to = '70s era Grotrians<FONT color=#0000ff> (I have no idea if it remains a problem = with their contemporary instruments)</FONT>. However, the bridge pin spacing was so = close that there was virtually no free space between the string and the = adjacent bridge pin. Consequently, there remain several notes on my client's = Grotrian 220 which have string noise at the bridge pins<FONT color=#0000ff> (which = varies in intensity according to the relative humidity at the time)</FONT>. A = gentle side pressure on an offending bridge pin will stop the noise.</DIV> <DIV><BR></DIV> <DIV>These Grotrian bridges from the '70s are prone to failure on = account of the close bridge pin spacing. There is simply insufficient bridge wood = around the pins to provide adequate support for the side thrust on the pins. On = Grotrians from earlier periods they have used a wider bridge pin spacing and they = do not have the same problem. Isn't it amazing how corporate knowledge often = fails to be passed down from one generation to another? The 'Johnny come latelys' = turn up with new thinking but fail give appropriate consideration to lessons = learned long ago by an older generation of thinkers. I'm all for innovative technologies, but one should come to it after stepping off from the = knowledge which has gone before.</DIV> <DIV><BR></DIV> <DIV>Clearly, the idea of placing a damping material on a noisy string segment<FONT color=#0000ff> (wether it be new-age silicon as in the = case of the Stuart agraffe, a piece of felt or a lump of fat from under the barbecue)</FONT>, its still is just a case of fixing the symptom instead = of addressing the cause of the disease.</DIV> <DIV><BR></DIV> <DIV>The bridge agraffe we have been discussing is a case in point. It = simply wasn't thought through prior to execution. I concur with your views Ron = N. and Del, with regard to widening the slots and using rolled pins as a = solution. Less overall height would be a plus as well. As you and I have both mentioned = previously Ron N., it would allow for the retention of a more sensible = bridge height and stiffness.</DIV> <DIV><BR></DIV> <DIV>Ron O.</DIV> <DIV><BR></DIV> <BLOCKQUOTE cite="" type="cite">----- Original Message = -----<BR>From: "Ron Nossaman" <RNossaman@cox.net><BR>To: "Pianotech" <pianotech@ptg.org><BR>Sent: November 01, 2003 8:23 = PM</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Subject: Re: Short Treble (sustain?)</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">I suspect the problem is with the = string buzzing against the side of the</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">slot.</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Del</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> Perhaps, though I have a hard = time imagining much vibration excursion in</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> that short segment. At that, = how difficult or more expensive is a wider</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> slot, as long as you're = cutting one anyway? It's not like it will cost</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> anything important in = rigidity. A grooved center rod would help too,</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">though</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> it would cost a bit more to produce.</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"> Ron N</BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite"><BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">-------------<BR><BR>As do I. I did = think it a possibility, though, as I worked with similar<BR>devices at Baldwin. = The easiest way to solve the problem (if it exists)<BR>(and, other than = putting some damping material between the leading<BR>termination and the = center deflector rod) is, as you suggest, to groove the<BR>center rod. This = could be rolled and, in quantity, is not as expensive as<BR>you might think. In = limited quantities, however, it might well be a factor.<BR>This can be used to = solve another problem as well -- the varying string<BR>deflection angles as = the wire size changes. I played around with several<BR>groove depths, deeper in = the low tenor and bass, more shallow in the<BR>tenor/treble.<BR></BLOCKQUOTE> <BLOCKQUOTE cite="" type="cite">Del</BLOCKQUOTE> <DIV><BR></DIV><X-SIGSEP><PRE>-- </PRE></X-SIGSEP> <DIV><FONT face="Times New Roman" color=#0000ff size=+1><B>OVERS = PIANOS - SYDNEY</B></FONT></DIV> <DIV><FONT color=#000000><I>   </I></FONT><FONT color=#0000ff><I>Grand Piano Manufacturers</I></FONT><FONT color=#000000><BR>_______________________</FONT></DIV> <DIV><FONT color=#000000 size=-2><BR></FONT><FONT = color=#000000>Web http://overspianos.com.au</FONT></DIV> <DIV><FONT color=#000000>mailto:info@overspianos.com.au<BR>_______________________= </FONT></DIV></BODY></HTML>