Below is the classic stereo application circuit as described in the original Sanyo datasheet. This configuration uses a split power supply (positive, ground, negative) and provides gain for both the left and right channels.
The heart of the circuit is the Dual Rail Power Supply.
The STK413-430 is a hybrid thick-film integrated circuit (Hybrid IC) manufactured primarily by Sanyo (now part of ON Semiconductor). It belongs to the renowned STK-400 series, which are class AB audio power amplifier modules designed for high-fidelity stereo applications. These modules were ubiquitous in home stereo receivers, cassette decks, and active loudspeaker systems throughout the 1980s and 1990s. stk413-430 circuit diagram
Unlike discrete transistor amplifiers, the STK series packs the entire output stage, predriver, and protection diodes into a single multi-pin package. For technicians, hobbyists, and audio restorers, understanding the STK413-430 circuit diagram is essential for repair, replacement, or building a custom audio system.
This article provides a deep dive into the internal block diagram, external application circuit, pin functions, power supply design, and common failure modes of the STK413-430. Below is the classic stereo application circuit as
The STK413-430 is a 18-pin SIP (Single Inline Package) hybrid IC. It is a class-AB audio power amplifier designed for stereo applications. It belongs to Sanyo’s famous STK series.
While it’s not high-fidelity by today’s standards (10% THD at max output is harsh), it is robust and simple to work with. The STK413-430 is a 18-pin SIP (Single Inline
The STK413-430 contains two independent amplifier channels. Internally, each channel consists of:
The internal schematic (found in the official Sanyo datasheet) shows that pins 5 and 12 (INV-) are the inverting inputs, which are used to set closed-loop gain with external resistors.