Useful to switch two instrument to an amplifier or to select between two amplifiers. IN A jack: Input Out B/ IN B jack: Input or output, depending on MODE; Mode 1: INB, Mode 2: OUT B Out A jack: Output Level A: adjust output level of A (in mode 2), Both in mode 1 Level B: adjust output level of B (It can be used in mode 2 only!) Power: 9V DC negative center
