2X Mono 300W Power Amplifier Board A1943/C5200 — High Rear Stage with Speaker Protection

Overview: This is a single-channel (mono) power amplifier board — use two identical boards for a two-channel (stereo) setup. It includes speaker protection and a high rear-stage design for robust output. Circuit topology: the input differential stage uses A970/C2240 high-voltage audio pair transistors in a dual-differential layout. Voltage amplification is handled by A1145/C2705, with mid-power driver pair A1837/C4793 feeding the output. Output stage: high-power pair A1943/C5200. Power supply: dual rail DC ±20V–90V. The upgraded version features optimized circuitry and components, but direct high-voltage application is not recommended above 90V — do not exceed the voltage limit. Performance: rated undistorted power 200W and maximum power 300W. With a sufficient power supply the board can readily deliver 200W of clean output, offering strong drive capable of easily powering a 15-inch speaker.