The white MTC-CBT-70T-WH Bolt-On Transformer Module from JBL is designed for adapting the CBT-70J-1 and the CBT-70JE-1 to be used on distributed loudspeaker lines. It allows long cable runs and multiple speakers to be driven from a single distributed system amplifier channel. There are transformer taps for 70V and 100V at 120W, 60W and 30W and an additional tap at 15W for 70V only.
The module connects to the amplifier through separately sold cables which run to the transformer's screw-down terminals inside the enclosure. Taps are selected by connecting the cable from the amplifier to the appropriate terminal on the internal terminal strip. There are two gland nuts for a water-tight seal and two mounting holes which connect to insert points on the back of the CBT-70J-1 or CBT-70JE-1 cabinet. The transformer is also UV, moisture and salt-spray resistant.