Hi ,I just bought a captor 16 ,I’m confused ....I’m using it as an attenuator for a Marshall 100 watt head into a 4 x12 can for a rehearsing situation ,I used to have a two notes Torpedo reload ...I would plug the amp into the reload Then the reload into the cab ,I would then turn the amp volume up to level 8 and I would then start to turn the volume knob on the reload up to get a nice volume level for rehearsal ,it sounded great I was getting the really great tones from a pushed amp at low levels but with the captor 16 it seems to work different or am I missing something ??? It seems you can only get a -20db attenuation and there is no volume knob on the device ?? Is this true or am I doing something wrong ,cheers