How often should Warchal strings be replaced?
The best time to change a single or entire set of strings depends on several factors. Two major factors are how many hours per day and how intensively they are played; and the corrosiveness of the player’s perspiration. The primary criterion is what your expectations are from the sound of your instrument. It is well-known that the durability of synthetic strings is generally shorter than that of metal strings. But synthetic strings give a player many more options to modulate the tone, so it's no wonder they are increasingly popular. There are at least three reasons why your strings should be replaced: the windings may break (especially on the A string); they simply do not stay in tune any more; they lose their quality of sound.
When worn-out, strings lose their quality gradually -- it can therefore be difficult to determine the right moment when the strings should be replaced. There is a commonly accepted limit of duration of 150 hours of playing, which for a professional player may mean something like six weeks. Nevertheless, many orchestral players and teachers play our strings several times longer. On the other hand, there are soloists that replace their strings even more often. My recommendation is to replace your string as soon as it does not stay in tune any more, in order to avoid the problem of reinforcing poor intonation Sometimes, it is enough to replace the string with the most wear (e.g. “A“) only, though a replacement of the whole set is certainly the best solution.