Sanyo STK is commonly known as Sanyo thick film. Under the control of calibrated sound and high-precision semiconductor technology production process, it is beyond the reach of ordinary amateur DIY players. In addition to better sound field and resolution, the low-frequency intensity is much stronger, which is completely different between professional athletes and ordinary players! These thick film circuits have always been customized products specifically for big brand audio manufacturers. Many famous factories in the early days used them to manufacture power amplifiers, such as K+H, Sony SONY, Panasonic PANSONIC, Kenwood KENWOOD, JVC, SAN SUI, Sharp SHARP, Pioneer PIONEER, AIWA, etc. Almost all Japanese audio manufacturers chose and used them for more than 20 years, which has influenced a whole generation and is also the sound with strong era imprint that we heard when we were young. It always sounds unforgettable. Sanyo, a company specializing in the production of amplifier modules, was later acquired by American company ON Semiconductor (NO). After the acquisition, Sanyo's traditional craftsmanship was integrated, combined with ON's unique design, making the later products even more outstanding. They are still adopted by large American companies such as BOSE and European Genelec!
I was fortunate to encounter a batch of brand-new power amplifier modules STK404-090 produced by SANYO in the later stage. This series of products has a wide range of models, from STK404-050 to 140. These products were produced in the later stage and feature typical classic circuits with relatively simple wiring and compact packaging. They exhibit impressive sound performance. The design output power is 50W @6 ohms, with a distortion level of THD0.4%. They can achieve satisfactory results when driving general bookshelf or floor-standing speakers. These thick-film chips were only supplied to manufacturers who made complete machines at that time, so they are relatively rare on the market.
This board is designed based on a highly enthusiastic concept, with all interfaces being solder-free and allowing for lossless installation. The materials used are carefully selected, and the power amplifier module can be installed either lying flat or upright, making it relatively easy to use with a suitable heat sink. (The filter capacitor used in this board is a second-hand disassembled product, with specifications of 35V 8100UF.). ）
Sound performance: The overall tone is warm, the sound is soft, the treble extends high without being harsh, and the bass is deep and elastic, without being muddy or dragging. The Sanyo thick film is a circuit that falls between integrated and discrete power amplifiers. Its fine workmanship and excellent craftsmanship surpass that of 3886 and 7294. Old players who have heard the combined machines of Aihua, SONY, etc. know that the sound is excellent. Generally, DIY players also find it difficult to achieve this level.
Power supply voltage: AC dual 22-35V (It cannot function properly if the voltage is higher or lower than this range. When using AC voltage higher than 24V, the filter capacitor needs to be replaced)
Output power: 50W@6Ω
Dimensions: 75W x 142L x 43H
Weight: 176g
