Sapphire 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 current of the class A mode, low output impedance and better load tolerance.

The Power amplifier is D.C. coupled, with a servo lock, ensuring excellent low frequency detail. For safety purposes the amplifier includes a D.C. protection circuit. This circuit is statically switched using extremely low impedance Mosfet switching devices. This circuit also soft switches the power amp on and off. The power supply is a low impedance design with a single custom made bi-filar wound transformer, with four separate windings. The main smoothing capacitors for the output stage are specially developed for professional audio applications with excellent ripple characteristics and long life. The Four power transistors per channel in the output stages are multi emitter devices with an output capability of 26 amps per device. The FBA-800 operates in the full balanced mode from the input of the unit to the output.