Complex sentence: Since the advent of microprocessors and digital signal processing, "modeling amps" have been developed in the late 1990s, these can simulate the sounds of a variety of well-known tube amplifiers without needing to use vacuum tubes.
Split into simpler sentences: Since the advent of microprocessors and digital signal processing, "modeling amps" have been developed in the late 1990s. These can simulate the sounds of a variety of well-known tube amplifiers without needing to use vacuum tubes.