PA-428PRO equips STK428-640,HI-FI Class D Power Amplifier Without Digital Flavor.
The STK428-640 is an audiophile-grade product introduced by Sanyo of Japan in 2000. Although it employs a Class D circuit, it has been meticulously crafted in strict accordance with Sanyo's traditional tuning style for Class A/B circuits, resulting in a warm and pleasing sound. It extends both low and high frequencies, preserving the sonic characteristics of Sanyo's thick-film circuit without the digital flavor commonly found in modern digital power amplifiers. Moreover, it delivers a substantial actual power output of 200W x 2 @ 4 ohms, unlike the exaggerated power ratings of some newer digital power amplifiers. This model boasts numerous features, including high efficiency, low heat generation, high power, and excellent sound quality, capable of meeting over 99% of audio amplification needs. According to its PDF documentation, each channel can achieve 200W of power under a 4-ohm load, with a Total Harmonic Distortion (THD) of only 0.8%.
Product parameters
Part No.:PA-428PRO
Chip:STK428-640
Input port:Bluetooth/AUX123
Bluetooth version:Bluetooth 5.3
Bluetooth protocol:SBC
Output power:
200W+200W 4Ω
100W+100W8Ω
Output impedance:4-16Ω
Magnification:100 times
Frequency response range:10-30kHz
Input sensitivity:275mV
Input impedance:50KΩ
Static power consumption:10W
Size:330×210×55 mm in width*depth*height
Weight:Approximately 5.2 KG
Input voltage:AC 230V
Recommended matching:3-15 inch passive fixed-resistance loudspeaker
