Dynaco ST-70 Series 3 Tube Power Amplifier

Back to the future. When Radial Engineering announced its plans to market a modern version of the Dynaco Stereo 70, the news struck me as a valiant time shift, aimed squarely at resurrecting the soul of one of the most influential amps of all time, and the component that enshrined Dynaco in audio’s Hall of Fame. Over a span of nearly 20 years in the 1960s and 70s, more than 400,000 ST-70s were sold both in kit and assembled forms, total sales by some estimates approaching half a million by 1977. That would make the ST-70 the most popular tube …