Not only is the ST-70 regarded as one of the most popular tube amplifiers of all time, it’s still widely sought after by vintage-audio enthusiasts. The Dynaco Stereo 70 was produced from 1959 to 1977.

Incorporating silver in ZnO has attracted a lot of interest in recent years to fabricate p-type ZnO, as the naturally occurring ZnO is n-type material due to its native defects such as zinc ...