Despite the many capabilities of modern plugins, every musician would agree that nothing can enrich the sound better than harmonics, and that’s the main reason why most of them gravitate to tube amplifiers. Today there are many plugins that imitate the work of tube devices by distorting the audio signal. What makes PS503 stand out from its rivals is that it enriches the sound naturally: the front panel is fitted with two special knobs which allow you to adjust the nature and amount of tubes and transformer harmonics.