The RX-series amplifiers are the reference for style and value, featuring high quality double sided circuit boards with SMT parts. Each component is computer tested before being instantly inserted and soldered by machine onto the PCB. The result is the correct part secured in the correct place for the lifetime of the amplifier. The RX series amplifiers are built tough with heavy duty heatsinks, robust unregulated power supplies, and oversized direct-input power and speaker terminals. Plus they sound sweet thanks to the audiophile grade bi-polar output transistors. If you want to upgrade your stock system without changing the head unit, the high level inputs make breathing new life into your stock system simple. RX-series amplifiers will power your audio system to new levels all day, every day without breaking the bank.