Bill, Although we often hear that the plate is a non-vibrating entity and that it does not contribute to tone, in reality it does sometimes. The hitch pin panel especially contributes to the high treble tone, although this is not consistent from one piano to the next. In applying torque to the panel you have stiffened it in some areas, most likely eliminating a "tonal sink" which was eating up some energy. This may also have helped the plate carry some of the strings energy to the air, like the soundboard does. This is a very risky thing to do, BTW, so everyone on the list who thinks about trying it: Use Discretion and very small changes! The tonal change may be subtle or it may not happen at all, so don't just keep cranking until you hear something. People like Heiner have a lot of experience around plates and what they can take, so personally I feel like I should know what they know before I do what they do! Don Mannino ---------- From: Bill Ballard[SMTP:yardbird@sover.net] Sent: Wednesday, June 24, 1998 5:04 AM To: pianotech@ptg.org Cc: YBarn@aol.com Subject: Down on the Hitch Pin Web Esteemed Colleagues, I'd like to know what's real here, so pitch in A 1901 Stwy B (with a new belly at the factory restoration center in 1941) sits in the carvernous dining hall of a local private school and is tried (and selected for use) by pianists involved in a summer chamber music program for college-agers just down the road. This piano has very respectable resonance judging by the direct sound (not being fooled by the ambient reverberation of the dining hall). The piano gets moved to the summer music program's main performance stage, a small, nicely remodled barn (we're talking rural VT here, gang), and immediately the musicians complain that the top third of the piano is dead. My first reflex, to file hammers, sharpens up the sound, but the impression of poor balance of that region with the rest of the scale remains for the pianisit, violinist and cellist preparing for the season opener. We explore many ideas. Given the tropical RH here ever since the end of May and the unaimous description "it sounds stuffed up", we choose to run the powerful air conditioning full time (and set about 200W worth of desk lamps on the floor under the board) on the assumption that high RH increases crown increases downbearing increases board loading which decreases sustain. (The standard dial indicator reads 10-15 mils of db in that region, and db throughout is ample.) Maybe the hammers are water-logged,though they're all ready filed down to the nub. Yes, although both spaces are remodeled barns, the smaller space has no reverberance. (For years it has relied on direct sound, and the consensus this morning is that the strings have no trouble projecting.) The pianist then mentions a technician once worked a miracle with a similar dead treble by adjusting the bolt which ties to the bell. (He has no idea in which direction.) I crank crank up 3/4 of a turn until the bolt is loose. The pianist plays, but nobody hears any difference. I go back down to the starting point, and beyond by 1/2 turn until it begins to require uncomfortable amounts of torque. In neither case does the dial indicator show a change in db. But going down, they all say, yeah that sounds more like it. What's going on here? Is there a real effect? There is of course Rick Davenport's oft-told story of Heiner Seinwald doing exactly this same thing (or recommending that Rick do the same). I can understand not seeing an immediate change in db on the way upwards, as the plate might not immdiately react to take new upward freedom. But what gives in the direction down when the db doesn't show a change and the musicians hear a difference? Is the pianist simply getting used to the newly filed hammers? I less interested in suggestion on voicing (or for that matter, new strings/hammers which it badly needs, or even discreet sound reinforcing) than on people's specific experience with reseting the htich pin web at the bell. But I'll consider all comments (including the one about the santero priest). TIA Bill Ballard, RPT New Hampshire Chapter, PTG "May you work on interesting pianos." Ancient Chinese Proverb
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