Understanding the pinout is critical for troubleshooting. The STK412-530 typically features a multi-pin SIP (Single In-line Package). While you should always verify with the specific diagram in your datasheet PDF, the general layout includes: Separate inputs for High ( VHcap V sub cap H ) and Low ( VLcap V sub cap L ) voltages. Input Pins: Signal inputs for Channel 1 and Channel 2. Output Pins: High-power output terminals to the speakers.