Road mic/line input, the number 1 priority (100 V) u optional input frequency range and tone control u limited radial device and automatic gain control (AGC) u can meet EN 54 ‑ 16 and EN 60849 standard system integration la10 PLN - 1 loop amplifier is a economical amplifiers, design used to drive the installation on the floor or the ceiling of the wire loop. Each amplifier can cover up to 600 square meters. This solution enables hearing aid users in the closed area of the lead loop to hear all broadcasts or music. The hearing aid user can set its device to T mode to receive signals from the loop. They can listen to radio with excellent sound quality, and there is no background noise or echo that usually results in hearing impaired people not being able to hear clearly. The basic loop amplifier can be connected to the line level output of the hybrid amplifier or can receive up to two microphone/line input signals directly. The 100v priority input can be used to connect up to the Plena voice alarm system. By monitoring this input, the existence of pilot tone can be determined. The built-in monitoring device monitors all the main functions of the loop amplifier, and the fail-safe relay can provide the fault state. This allows the user to use a loop amplifier in a system that complies with IEC 60849 and includes an induction loop in the monitoring transmission path. To improve comfort, the loop amplifier is equipped with a spoke limiter that keeps the output field strength below the pre-specified 100 mA/m. In addition, the circuit can be set as automatic gain control (AGC) mode, so as to enhance the weak signal at the same time when weakening the strong signal, so as to improve the clarity. This ensures that all information is broadcast at a comfortable, pleasant volume level. The device is equipped with tone control and metal loss compensation circuit, which can adjust sound according to transmission materials and environment. These controls can be locked to prevent others from changing after adjustment. Loop amplifiers can be stacked (primary/secondary configuration) to cover large areas and support low overflow scenarios. Its unique square configuration can even provide uniform and uniform field strength through multiple loops. Front side of controller and indicator light • LED power meter • ammeter • 4 LED indicators, Used to indicate a fault, loop wheel, AGC and limit the whole sex, headphone socket, two tone controls, three input volume control (main and two channels), switch on the back, the loss of metal compensation control, monitoring, voltage selector, frequency range switch, AGC/limit wheel switch, scope of AGC control, VOX/hybrid switch, switch front/rear amplifier, two phantom power switch, interconnection on the back of the mic/line switch, the main input, two aux output