Heating cold winter air can cause very low humidity levels (30 - 40% rather than the usual 50-65% we see in the summer). Timber shrinks across the grain when the humidity is low and this often caused dampers to be less effective in the winter.

Let me explain: When we heat cold winter air it becomes very dry and dries timber. Since harpsichords and spinets tend to be made with the wood grain running round the case, the case height will often shrink by as much as 1-2mm. This reduces the distance between the top of the keys and strings. Since the grain in wooden harpsichord runs vertically, the jack remains the same height. This can cause the dampers to lift off the strings even when the jack is at rest. In extreme cases, the plectra may not return below the strings. This lack of damping will be most noticeable in the bass.

What is to be done? Many harpsichord makers include some cardboard packing under the keyframe or below the cloth at the back of the keyboard that can be removed if the case shrinks. Look for this and remove it if it is there. Some jacks have screws at the bottom which can be adjusted to shorten the jack. If you can't do either of these things, you will have to lower each damper or sand a little of the bottom of each jack. Make sure that this is the best option available to you before you commence. Seek expert advise if you are unsure.