I owned a pair of TDC speakers in the early 70s while still in high school. Don't remember the model number but I do remember they were purchased from Tech Hifi which was an audio retailer in New England at the time. Don't know if they are still in business or not. I believe the TDC line was produced exclusively for Tech Hifi but don't quote me on that. When I purchased (actually my father purchased) the speakers we auditioned JBL, Advent and BIC along with the TDC. The TDC was much less expensive so that's how we went. I thought they were great at the time but haven't seen or heard them in years.
I've seen questions about TDC here before so you might search the archives. Good luck.
I've seen questions about TDC here before so you might search the archives. Good luck.