A synthesized low Distortion Function Generator. It has adjustable source impedance from 10 Ω to 640Ω in steps of 5Ω via keypad entry. The output voltage ranges from 50uV to 20Vrms. Freq resolution is 1Hz over full range. A freq & level sweep function is available. Signal distortion is overall 0.1%. Output configuration can be balanced or floating; Balanced grounded or unbalanced grounded.