Sugden Sapphire FBA-800 Class A Power AmplifierSapphire FBA 800 Pure Class A Power Amplifier The FBA 800 is our most advanced power amplifier. The floating bridge design combines four 20 Watt amplifiers in a single stereo chassis and provides several key benefits. Each channel consists of two amplifiers working as voltage amplifiers driving an output stage of bridged power transistors. The advantages are a low noise floor, better power output relative to the voltage rails (x2) and with the fixed