The Skywave Germanium Drive is an adaptation of the Hudson Electronics Broadcast, a germanium preamp/overdrive pedal based on vintage broadcast consoles from the 1960s. It uses a hybrid of silicon and germanium transistors in class-A configuration, plus a transformer at the output that saturates on higher drive levels.
The Broadcast was originally released in 2015, and has since had a few new variants including one that runs on 24V and another with a second footswitchable gain mode with its own level control. (There was also a limited-run version that combined both of these features into one.)
The Skywave is primarily based on the original Broadcast, but it adds a voltage-tripler circuit to allow selectable 18V or 24V power from a standard 9V supply. It also incorporates a 3-way gain switch, adding an extra position adapted from the 24V version of the Broadcast.