And here we are again. This time I have an interesting issue about sound improvement by = changing the position of a back check. I learned this at my last = course in Hamamatsu. It is as follows: a couple of days ago I was asked to go to a Yamaha = dealer who had a complaint about a new Yamaha S6 (the handmade Yamaha = copy of the Steinway B, for those who do not know) being too soft. There was no power in it due to very bad regulation. So first I checked the down weight, found it a bit high, and made the = action a bit faster so that the down weight was a little less (just a = little, mind you). I then made a complete regulation from beginning to end followed by a = tuning. The treble was OK now but the base was still too weak. I decided to = use the trick with the back check. Here it comes: Take the action out, put it on a bench or table. Push down a key (belonging to the soft sounding part) very slowly, = you feel the motion of hammer drop (careful now) you keep the key = pressed down, you look at the exact space between the lowest point of = the hammer tail and the highest point of the back check. How much is it? is it 3 mm (sorry again, darned europeans) is it = more? When the distance between these two points is more than 2 mm, = screw the back check one complete turn (360=9A) up. In Japan every technician has a custom made hardwood pipe which fits = over the back check (a rectangular hole). Put the action back. Now listen again, you'll be amazed! This one key = sounds better, it has more power than before! Just make sure that the distance is not less, than 2 mm! And if you have to turn the back check down, be careful, the metal = thread might break. This is a very powerful trick! Naturally, everybody knew this allready and therefore my question to = yall is: What is the explanation for this??????? My teacher in Japan did not know. Nobody I asked here in Holland has = an answer. WHO does? PS. don't forget to check the hammer blow distance... friendly greetings from: Andr=E9 Oorebeek CONCERT PIANO SERVICE Amsterdam, the Netherlands email: oorebeek@euronet.nl =83 where MUSIC is no harm can be =83
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