Hi. I bought a used Chinese made scherle roth violin. The original price was 300 USD so it's a low end instrument. The notes all sound fine except the A string's c sharp note. When I play it it vibrates abnormally with cross tonality. In other words imagine hitting c and csharp on a piano at the same time - that's how it sounds.
This isnt a case of me putting any vibrato on the string through my bow or finger pressure. This isnt a case of accidentally hitting the E string at the same time. It doesnt occur on other notes or strings. Naturally I replaced the string and examined the head and bridge and soundboard for imperfections but cannot locate the source of the jittering sound. Any thoughts?
Playing D or C sounds fine but the Csharp whirls like a helicopter sound when it takes off.
Mark