Luxman output transformer OY15-5K. It was attached to a handmade vacuum tube amplifier. Sound was coming out of the amplifier, so I believe signals were being sent, but there is some crackling, and the environment is not ideal, so I am selling it as junk. Please check the condition in the photos. To prevent any problems, no claims and no returns are accepted. If you have any questions, I will answer them to the best of my ability. Thank you.