1.amp,receiver,RS232,USB 2.linking time 3 seconds 3. ... used classroom bluetooth amplifier, teaching aid equipment amp Function/ Strong pointThis teaching aid equipment amp is 2.4g wireless audio system used ... level inputMIC:15mV(unbalance )circuit:200mVTreble : 10 KHz±12 dB Bass: 100Hz±12dBsignal-to-noise ≥86dBoutput powerOutput power:2×50W ... have any question ,Thanks a lot! teaching aid equipment amp