What this board does Singlechannel power amplifier board designed for output audio: with an adequate power supply it can easily reach 200 (depending on supply), deliver strong driving force, and drive a 15inch loudspeaker without strain. Ideal for applications that need clean, current output from a compact amplifier board. Key benefits — why you need it drive capability: designed to push large speakers (15') with solid lowfrequency control and headroom. Robust output stage: a power topology that provides reliable current delivery and low distortion under load. Clear upgrade path: an optimized upgraded version improves circuit layout and component selection while preserving compatibility. Circuit and component highlights (exact models) Frontend differential pair: A970 / C2240 in a doubledifferential configuration for stable input stage performance. Voltage/current amplification: A1145 / C2705 used for amplification driving the power stage. Driver/power pair: A1837 / C4793 as the promoted power driver pair for the output stage. Output transistors: A1943 / C5200 power pair in the final output stage for current delivery. Power and supply requirements Dualsupply design. Rated for negative rail in the range of 20V to 90V. The upgraded version retains the same voltage range but uses optimized circuit layout and parts. Practical recommendation: use supplies below 90V; do not exceed the specified voltage limit to avoid damage. Compatibility and system notes Singlechannel board: for stereo systems you must use two identical boards (one per channel). Designed to work with conventional speaker loads and sufficient power supplies; match supply capability to desired output level. Typical use scenarios 1. Live sound reinforcement: power a 15inch PA speaker for small to medium venues where strong lowfrequency drive and headroom are required. 2. DIY amplifier builds: integrate as the main power channel in custom singlechannel or bridged amplifier projects; use two boards for stereo units. 3. Studio/band rehearsal rigs: deliver dependable, punchy output to monitor wedges or fullrange 15' cabinets. Practical recommendations Ensure the power supply can deliver the current and voltage required for your target output (the board can reach 200 with adequate supply). Use two boards for stereo applications; confirm matching components and wiring for balanced performance. Observe rail voltage limits and thermal management for reliable longterm operation. What makes this board stand out Purposeful transistor topology using A970/C2240, A1145/C2705, A1837/C4793, and A1943/C5200 — chosen for reliable differential input, solid amplification, and current output performance. Optimized upgraded version available that improves circuit and part selection while retaining original specifications and operating limits.