The Power Plug 100 offers the same -10db as the Power Plug Lite (M-PPLITE) but adds another "Bedroom Level" pot for further attenuation of up to -30db AND is suitable for amps up to 100 watts!
Turn your tube amp UP to drive your power tubes. This is where tube amps blossom and where players get in trouble. Use the attenuator to drop your overall volume to more tolerable levels. You can dial in your breakup, which may be too loud, then attenuate to lower the overall volume. So you can adjust your amp as usual and use the attenuator as an overall Master volume.