Electro-Voice TK-150 70/100 V Transformer Kit

The TK-150 converts an EVC, EVF or EVH install cabinet from low impedance to a 70.7 or 100 V distributed line, so a run of speakers can share one amplifier channel up to that amplifier's rated power. It fits inside the loudspeaker: the input panel comes off, the transformer seats in the pocket on the left, and the mounting ears bolt to the four input-panel bosses.

One thing to get right before you power it up. The TK-150 needs a 50 Hz Butterworth 24 dB/octave active high-pass filter ahead of the driving amplifier, and running it without one can damage the amplifier. Drive the 100 V line into the 150 W 70.7 V tap and the transformer will pass up to 300 W to the loudspeaker, but that configuration wants the filter moved up to 66 Hz or higher. Against the EN54-24 simulated program signal it is certified to 400 W on the 100 V line.