Ringing noise

[prussell]

Hi Piano-Tuners Forum,

I have three knotty problems that I'm hoping someone can advise me on.

Firstly, I have a '72 u1 Yamaha. I've taught myself to tune it over the last few years, and am very happy with the results. It has a nice sounding bass section, the copper on the strings looks really new. The bass I can get sounding really fine! However, the three stringed notes in the mid/upper registers are proving impossible to get 100% in tune. I'm a professional string player of over 30 years, so my ears are spot on, moreover, my computer tuner shows graphically what I can already hear. The final pitch produced after much fiddling is a whining, ringing noise which sounds in the high frequencies. I wouldn't describe it as a beat, but it may be a slow, harmonic distortion of some kind. By muting out one of the three strings, usually I can cancel the effect, but never, however much I tune the instrument, can I get it to disappear .I had the piano looked at by two piano tuners. Both made a great job of tuning it, a professional job, but the ringing effect remained. One tuner told me to just get used to it. But its a horrible bell like overtone that rings through the middle of the piano. I wonder if someone once changed the bass strings, but not the treble section. Do my aural sensations bear out any familiarity to anyone?

Secondly, I would add that someone in past has driven 6 screws in the treble side of the soundboard. I'm wondering why this might be?

My third and last question is to do with dampers, they make a scratching noise as they pull away from the string. Again, the tuner said to get used to it. It only happens in the D-Eb in the lower-mid (where the dampers have two wedge shapes, i.e they are not flat). Can this be fixed?

Thanks to any that reply!

[Colin Nicholson]

If the piano is about 40 years old as you say, then the occasional string will produce false beats - it is either slightly corroded, or has a flat/ "pear shaped' spot where it has been stretched over the years - quite common, and although its Yamaha, it can happen on any piano. The string(s) in that tri-chord section may need replacing.

Damper felt has probably hardened (sometimes due to moisture, then drying out) - again, replace the offending felts & backing cloth.

[Withindale]

A few points:

Have you tried manipulating the damper felts a bit? That can help. I did that a couple of days ago to one on a bass string and now it damps like the others.

More generally, have you done any basic servicing and regulation?

I'd suggest you put up a photograph or two of the six screws in the soundboard.