Modern audio products are changing from conventional solid state to a much more efficient “switchmode technology” (often called Class D) that delivers more power with lower losses and lighter weight. The new technology is more complex and has stringent regulatory requirements, so it’s been developed first for large-scale applications such as cellphones, home theaters, car audio systems and large PA amplifiers. Meanwhile, the guitar industry is still stuck in the tube era. Pat Quilter, founder of QSC Audio Products and a veteran designer with over 50 years of experience, is one of the few designers whose career spans tubes, solid state, and the new switchmode technology. His mission is to combine a deep love of music, a deep understanding of tube behavior, and his expertise in switchmode design, to create new tools that will expand artistic possibilities, relieve performers of excess burdens, and exploit the latest mainstream technology to deliver higher quality and satisfaction at an affordable price.