Sanyo STK, commonly known as Sanyo thick film, is not a level that ordinary amateur DIY players can achieve, thanks to its tuned sound and high-precision semiconductor process control. Besides better soundstage and resolution, its low-frequency dynamics are significantly stronger, which is the difference between professional athletes and ordinary players! These thick film circuits have always been customized products specifically for major brand audio manufacturers. In the early days, many renowned factories used them to manufacture power amplifiers, such as K+H, Sony, Panasonic, Kenwood, JVC, Sansui, Sharp, Pioneer, and Aiwa, almost all of which are Japanese audio manufacturers. They have been used for over two decades, influencing an entire generation, and also the sound with a strong imprint of the era that our entire generation heard when we were young. It is unforgettable every time we listen to it. The company specializing in the production of power amplifier modules was later acquired by ON Semiconductor, which integrated Sanyo's traditional craftsmanship with ON's unique design, making later products even more outstanding. They are still adopted by major American companies such as BOSE, and European companies like Genelec!
Fortunately, I came across a batch of brand-new power amplifier modules STK412-530-E produced by SANYO in the later stage. It is said that these Earth brand packaged gray shells are all products from the period after ON Semiconductor acquired SANYO's production line. They incorporate ON Semiconductor's design and technology. The appearance of products produced during that stage changed from the traditional ugly black shell of old SANYO, becoming exquisite and detailed. The internal craftsmanship also improved significantly. Objectively, the sound quality far surpassed that of old SANYO. Unfortunately, only a few of those products are still available today. At that time, the vigorous development of the Internet and the widespread popularity of various portable devices (especially large-screen touchscreen phones) made many people gradually forget these high-performance desktop devices. Those once renowned audio manufacturers had no choice but to change their product direction, resulting in these customized products being stored in the warehouse of the original SANYO packaging factory in the Philippines for more than a decade.
Until the end of last year, a friend from Shantou introduced us to this batch of products, but at that time, we couldn't find any reference materials for this product on the internet. With the help of my friend Ah Liang, we only found an application screenshot of the product on a foreign website, and then we dared to purchase this batch of products.
After receiving and testing the module, we found that it possesses considerable potential and its actual power output surpasses that of STK412-430. Furthermore, it utilizes both high and low voltage power supply. Due to the lack of official documentation, we have tentatively set its power output at 200WX2, with a recommended operating voltage range of ±45V. The maximum operating voltage should not exceed ±52V. (The schematic diagram actually requires both high and low voltage power supply. You can refer to the schematic diagram in the link.)
This product is a test version, and it will be installed and tested before shipment. The finished board comes with a radiator as shown in the picture, but it may not be sufficient for high-power use in actual practice. You can add a radiator according to your actual usage situation.
Power supply voltage: AC dual 24-36V, transformer power is recommended to be above 300W.
Output power: 200W x 2
Impedance: 4-8Ω
Dimensions: width 120mm, height 55mm, depth 140mm
Weight: 0.45KG
