OSD Black 50W70T Commercial Distribution Line Matching In-Door 70v Transformer, (50W, 40W, 30W, 20W and 10W)


Our Black Series BK50W70T is an 70V matching line indoor audio transformer that converts the primary voltage of a PA or audio amplifier from 70V to 8 ohms or 4 ohms to eliminate power loss caused by long distance runs between the amplifier and speaker. Our audio transformer offers full range frequency response, 20Hz to 20kHz (plus minus 1dB), for no insertion loss or effect on sound quality. The BK50W70T includes 50W, 40W, 30W, 20W and 10W taps that allow different power levels and volume for each speaker. The more power you have, set the taps higher. The less power you have, set your taps lower for a truly customized distributed audio system that won’t overload the amp. Six-inch cable leads give you plenty of room to work around, and the BK50W70T includes a self-adhesive pad for quick and easy installation.


  • Eliminates power loss between amplifiers and speakers
  • Allows longer speaker runs on large indoor installations
  • Includes 70V primary amplifier input and 8 and 4-ohms secondary speaker output
  • Easily connects between the speaker and amplifier
  • Includes 50W, 40W, 30W, 20W and 10W taps
  • Works with audio and PA amplifiers
  • Includes self-adhesive pad
Technical Specifications
More Information
  • Primary voltage: 70V
  • Power handling: 50W
  • Primary taps: 50W, 40W, 30W, 20W and 10W
  •  Frequency Response 20Hz to 20kHz plus/minus 1dB
  • Insertion loss: 1 dB
  • Secondary impedance: 8 and 4 ohms
  • Mounting dimensions: 3.37” W X 2” D X2” H
User Manual bk-50w70vt_manual.pdf