Note: Pinout and functions differ among STK413–430 variants; always consult the specific datasheet for pin numbering and absolute maximum ratings.
The STK413-430 belongs to the STK413 series. It is a Class AB push-pull stereo amplifier. Being a "Hybrid" IC means it combines bipolar transistors and thick-film resistors on a ceramic substrate, packaged inside a plastic shell with a metal heatsink. This design allows it to handle significant power while maintaining thermal stability.
Key Specifications:
| Pin | Name | Description | |-----|-------------|---------------------------------| | 1 | +Vcc (R) | Right channel positive supply | | 2 | Out (R) | Right channel output | | 3 | GND (R) | Right ground | | 4 | -Vcc (R) | Right negative supply | | 5 | Bootstrap R | Bootstrap capacitor for right | | 6 | NF (R) | Negative feedback right | | 7 | Input R | Right channel signal input | | 8 | GND (signal)| Signal ground | | 9 | Input L | Left channel signal input | | 10 | NF (L) | Negative feedback left | | 11 | Bootstrap L | Bootstrap capacitor left | | 12 | -Vcc (L) | Left negative supply | | 13 | GND (L) | Left power ground | | 14 | Out (L) | Left channel output | | 15 | +Vcc (L) | Left positive supply |
(Check your specific datasheet — some STK41xx have GND on pins 3 and 13, and ±Vcc swapped for left/right.) stk413-430 circuit diagram
Before analyzing the circuit, let us review the electrical characteristics. Operating at ±27.5V (typical) to ±38V (maximum), the STK413-430 delivers:
These specifications indicate a medium-power amplifier suitable for bookshelf speakers or small to mid-sized listening rooms. Before analyzing the circuit, let us review the
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.
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. and audio restorers
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.