I went to a clients house today to do some service work which he requested for me to do on 3 of his pianos. He has 7 pianos in total. Apart from the pianos which I worked on, the client asked me to assess his Albert Fahr grand for the reason that the hammers have become muffled overnight. The piano has always had a mellow/not to bright sound/tone.

Overnight the hammers have become muffled/wooly, particularly the middle range of the piano. The hammers need a light filing because they have 1-2mm grooves in them.

The client is an extremely accomplished pianist and plays on all of his pianos regularly. The Albert Fahr grand is one of five pianos in a single room. The room has a stable environment.

Why would the hammers become muffled/wooly?

Advice would be much appreciated!

Best regards

I would say something happened with the una corda. The hammers are no longer hitting where the strings have already packed the felt, but a bit between the grooves where the softer ridges are. They still might benefit from reshaping, but I am betting that if the una corda is adjusted, or the paper clip or whatever that is hanging it up is removed, then the tone will return to normal.

Hello Jeff

Thank you! What you have said sounds like the answer. I will have to have a closer inspection. One would think that pulling the action out and then pushing it back in might have solved the problem if something was stuck inside the piano/cavity somewhere, but obviously not! I will have a closer look when I return to his house.

Best regards

I was about to suggest that perhaps it was a missing cat that was to blame.
But since I am not a piano technician (can you tell) I'll go with Jeff's suggestion.

Someone may have had a wedge or shim of some kind keeping the action where they wanted it. It's possible that when you slid the action out and back in it removed the shim.

Jeff I spoke with the client today and told him what you had said in your post above and the client then said he knows that the mechanism is moving towards him (forward) a certain amount when the una corda pedal is depressed. So Jeff, you were half right!?!

I will be returning to the clients house in the very near future and then will assess the matter more thoroughly and do the necessary adjusting/repair.

Thank you

Take care

Mark:

Thanks for the update. Sounds like a problem with the pins going into the cheek blocks, or the cheek blocks are moving themselves. The keyframe should only move side to side as I am sure you know. It’s all part of the una corda. Let us know how it turns out.

A while ago I tuned a small grand that had a screwed down key frame. It had to be put exactly back into position to sound right. It may not be much of a piano, but is so important to the owners that they gave up their dining room table to make room for it. So when they have company, they use the grand to eat off of!

I recently tuned a small grand and was having trouble tuning the right unisons in the upper register. The sound was very weak and when I pulled on the right string, I got no change (which can open your eyes in a hurry). I peered at the hammers while striking the note and the hammer was only hitting 2 strings. At first I thought maybe the una corda mechanism was caught on something, so I removed action and inspected. Looks like the hammers where never spaced to the strings, they were nicely grooved as is. Had been that way for years. No going back now.