Sony MHC-RG490S/RG590S – power amplifier and power board schematic

Using ICs: STK412-240, STK403-130, STK 404-130

Schematics [Power amplifier] STK-403 130

STK 412-240 Power amplifier schematic

STK 404-130 Sub-Woofer schematic

Mains transformer board schematic