| The X models came after all one digit B's were taken. X1 is the " B10" or something like that.
The S models were the Schilke answer to the Strad., heavier with braces in the main valve etc.
With some exceptions I think that the B nomenclature is according to born date.
The Schilke loyalist has a details of each model regarding bore, bell etc.
Gus |