R5 is an optional load resistor, which reduces residual hiss when the amp is driving low impedance headphones such as the Grados (32 ohms).是什么意思_R5 is an optional load resistor, which reduces residual hiss when the amp is driving low impedance headphones such as the Grados (32 ohms).在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句