Good morning everyone, I am a beginner and I am taking piano lessons; I own a Yamaha upright piano and I have a problem with one note, the A located in the last space of the bass clef, key 25 to be precise. When I play it, it produces a metallic sound that bothers me during exercises; I tried to figure out where it comes from and it seems to be the two strings, though they seem intact to me. The metallic sound doesn't only happen if I play by "caressing the key". At this point, I believe it is a poor adjustment made by me when I replaced the cords that break in these pianos.
If it is a copper-wound string, it could be the winding. However, if that is the case, something can be corrected by voicing the hammer slightly. But an expert technician must do it. If it is the string, one must check that the copper winding has not become uneven at one of the terminal parts. Otherwise, it must be replaced.....actually, both must be disassembled and replaced. The old ones are kept as spares...especially the good one. Both, because the timbre changes between the existing good one and the new replacement one.
Unfortunately, it cannot be seen. You can only check at the apex and turn it clockwise with pliers. If it makes a lot of metallic noise, the strings must be replaced
Since it might be helpful, I am posting the solution; I should preface that I didn't find it myself and I didn't do it myself, but rather a very skilled professional. Basically, the hammers were too compacted and therefore were creating that metallic noise; practically, he pricked them with a tool with needles in order to create air spaces inside the small hammers—not all of them were treated, only those out of tune.
This is the voicing intervention, which must restore the correct elasticity to the hammers in certain areas of the felt to the benefit of others which, by remaining hard, enhance the correct harmonics at the moment of impact with the strings. This intervention must not be practiced deeply in some areas, such as, for example, the tips of the hammers, lest it results in the flattening and dulling of the sound. Surely the technician intervened with expertise and caution. Well done.
