Description
High-Output 60W Mono Audio Power Amplifier Module
The STK4038II is a robust thick-film hybrid integrated circuit from Sanyo's trusted "Series II" line. Capable of delivering a continuous 60 Watts of power, this module is an essential replacement part for high-performance vintage receivers, dedicated subwoofers, and active monitor systems from the mid-80s and 90s.
Known for its thermal durability and reliable power delivery, the STK4038II features a built-in constant current circuit to minimize power-on and power-off shock noise ("thump"), ensuring your speakers remain protected during operation.
Key Technical Features:
- Continuous Power Output: 60W Minimum (at 8Ω, 20Hz to 20kHz, THD = 0.4%).
- Configuration: Mono (Single Channel) in a 15-pin hybrid package.
- Reliability: Series II architecture optimized for low thermal resistance (1.4°C/W).
- Frequency Response: Full-range audio capability from 20Hz to 50kHz.
- Operating Voltage: Recommended ±38V (Absolute Maximum ±57V).
- Pin Compatibility: Member of the 30W to 100W pin-compatible series for flexible repair options.
Installation & Safety Notes:
The STK4038II generates significant heat during high-output sessions and must be mounted to a substantial heatsink with high-quality thermal silicone grease. Operating this module without a heatsink—even for a brief functional test—will cause immediate and permanent internal substrate failure.
Technician's Tip: Before installing your new STK4038II, please verify that your power supply filter capacitors are fully discharged and that the output emitter resistors are intact. Many original failures are caused by external speaker shorts that must be corrected to protect the new module.