2.1 channel hi-fi audio amplifier circuit by Technical Mriganka, a 164 KB PDF. The title does not name the amplifier ICs or output devices, so identify them from the diagram itself. Hobbyists use such drawings to build stereo-plus-subwoofer systems and to troubleshoot dead channels, distortion or hum by tracing the supply and signal paths. Compare part numbers with datasheets and confirm the transformer and rail voltages suit the design.
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