The Power Soak was the first commercial product by Tom Scholz. It wasn't named "Rockman" as this trademark was introduced only in 1982 at the creation of the headphones amp. The Power Soak is therefore "Tom Scholz's Power Soak".
 
Though the Power Soak was not the first power attenuation device for guitar amps, it was the first to be 100% reliable, the first to respect the sound of the amp. Most of all, it was the first to include a volume control: the previous devices were only dummy-loads without setting.