把功放(适用于30W 以下的功放)喇叭端转为低电平音频线路输出信号，
单声道输入转模拟立体声输出；
带隔离变压器，共地隔离功能；
板上有接地开关，一般BTL功放选择不共地(OFF)，OTL，OCL选择共地（ON)；
假负载开关，一般大功率D类功放、电子管功放不允许空载，OCL、BTL、OTL可以空载，根据实际需要选择；
板上有假负载电阻，原功放如果没有接喇叭选择ON，接了喇叭选择OFF；
衰减量：-4dB至-30dB，可以调节输出音量大小，
输出接口：3.5mm，RCA莲花。
Converts speaker‑level signal from amplifiers (suitable for amplifiers below 30W) to low‑level line‑out audio signal.
Mono input to analog stereo output.
Built‑in isolation transformer for ground‑loop isolation.
On‑board ground switch: set to OFF for BTL amplifiers (non‑common‑ground); set to ON for OTL and OCL amplifiers (common‑ground).
Dummy load switch: High‑power Class‑D amplifiers and tube amplifiers shall not operate without load. OCL, BTL and OTL amplifiers support no‑load operation. Select according to actual application.
On‑board dummy‑load resistor: Set to ON when no speaker is connected to the original amplifier; set to OFF when a speaker is connected.
Attenuation: ‑4dB ~ ‑30dB, adjustable for output volume level.
Output connectors: 3.5mm jack, RCA.
