THDY-100 Thomastik Infeld Dynamo violin string set 4/4 medium THDY-01 Thomastik Infeld Dynamo violin string E-1 4/4 medium THDY-02 Thomastik Infeld Dynamo violin string A-2 4/4 medium THDY-03A Thomastik Infeld Dynamo violin string D-3 4/4 medium THDY-04 Thomastik Infeld Dynamo violin string G-4 4/4 medium THDY-03 Thomastik Infeld Dynamo violin string D-3 4/4 medium synthetic core