I recently got a Yamaha U1 acoustic piano. It sounds great except the E below middle C (E3) is much too loud. Whenever I play a chord with that key it really stands out and dominates the sound. No other keys on the piano are effected this way.
When I play with the soft pedal or the sustaining pedal the E3 key is still too loud. However, if I play with the practice pedal then the effect goes away and all pedals have a similar volume.
As far as I can tell the hammer doesn't move any faster than those around it, and it doesn't sit in a different position. It looks just like its neighbors in both these regards.
I've got some pictures of the hammers around the problematic key, which is the second from the left in these two images:
For comparison here is a picture of the hammers for the keys from D3 down:
Can anyone tell me what the problem could be? I think the felt of the problematic hammer may be worn so much that it has hardened, which would explain why I don't hear any difference when playing with the silent pedal. Is this possible? Has anyone seen anything like this before?