Some instruments don’t work well with synthetic or gut core A strings.
They may sound gritty and there can be a problem with response
especially in the higher positions.
This is why many violinists,
particularly Russian ones, prefer metal A strings. Warchal designed the
Russian Style A for these players a few years ago.
The Russian
Style violin A string gives you a seamless and mellow switch between the
alto and soprano registers, excellent response and incredible
durability.