Looks like Dale answered this one . Here is a photo of the bottom of a B soundboard: [link redacted at request of site owner - Jul 25, 2015] Erwinspiano@aol.com wrote: > In a message dated 10/17/2003 3:48:32 AM Pacific Daylight Time, > michael@gambles.fsnet.co.uk writes: > > Hello John Hartman > You've got a really good thread going here - I hope you don't mind me > joining in a bit? My model "A" has, what the London Steinway people > call a > "Tone Bell". Is this what you are calling the "Pulsator"? It can be > seen to > be there by simply looking at the frame on the treble side. There > you will > see, or will not see the square head of what apperas to be a large > "carriage > bolt". Looking underneath the piano there is this inverted conical > casting. > I note in my rounds that it is only the Steinways with the > "Sostenuto" pedal > which has this feature - be it an 85 note or an 88 note keyboard. > As to creating a new piano from scratch I leave that sort of think > to that > Italian chap Fazioli (I think that's his name) Anyone had experience of > these "wunder-pianos"? > Regards > Michael G (UK) > > Michael > The tone bell & pulsator I asked John about are not the same > thing. The pulsator is merely a thin strip of maple about 25 mm wide by > 7 mm thick by 6 cm long. Depending on the year this feature intersects 3 > to 5 ribs. Looking under the piano at the board of a S&S B & C you'll > see it in the bass corner. It runs 90 Degrees to the ribs and is > glued/dowelled to the ribs. The ribs are also thinned out & seem to > terminate somewhat at this point even thought he thinned out flatter > portions extend to & are glued into notches in the rasten/inner rim. As > John said it appears to be an idea that functions like a cutoff bar but > I'm thinking it may have an effect hard to quantify. Surely they had a > reason. > The bell is just a plate stiffening device. A short beam from the > belly rail to the case in the same area would allow for another nose > bolt that could take the place of the bell. I cant say the bell has any > effect in and of itself to influence tone but does stiffen the plate web > where it attaches thereby influencing tone. There must be a modest down > force of the bell bolt to do so which by the way will increase the > downbearing a small amount (tone effect) These bolts also seem to come > loose from time to time and cause a weird rattle. > Does that help?--Dale -- John Hartman RPT John Hartman Pianos [link redacted at request of site owner - Jul 25, 2015] Rebuilding Steinway and Mason & Hamlin Grand Pianos Since 1979 Piano Technicians Journal Journal Illustrator/Contributing Editor [link redacted at request of site owner - Jul 25, 2015]
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