Yanagisawa supposedly makes a low A soprano.. Selmer has made low A altos, and a C-melody. Conn made the Conn-O-Sax, which was keyed to Low A. Eppelsheim is currently making a Contrabass with a low A. Keilwerth has made a few Bass Saxophones with the Low A. Some Brazillian Saxophone makers/modifiers are making horns down to low G!!!!
Steve P