Industry standard, high quality transformers with audio grade laminations offer low insertion loss and full-range frequency response. Insertion loss will not exceed 1.0dB and the frequency response is +1dB from 60 Hz to 12 kHz. Primary taps are .5, 1, 2 and 4 watts. Secondary impedance is 8 ohms. Model HT-47 is designed for 70.7-volt lines and Model HT-42 is for 25-volt lines.