Looking for an amp for practice and smaller gigs at bars. Is the Rumble 100 really 100 watts? I know the 200 and 500 are not until you add additional cabs but there is no extension speaker connection on the 100. I played a 100 today along with an old, used GK Backline 112 which is a 100 watt 1x12 and it was considerably louder than the Rumble. Also played the GK MB110-II which is a 100 watt 1x10 and that was also louder than the Rumble. I had to put the gain at 1 o clock and the master ar 3 o clock on the Rumble to match the volume of the GK amps with the master at noon.
The v3 rumble 100 is indeed 100 watts alone - as for volume, I can't help much there, except to say that the rumble series (I can vouch for the 40 and 100 anyway) has 100% usable volume... I wouldn't personally run them dimed out all the way just on principal - though I honestly don't think it'd hurt them if you did, and the sound does not suffer if you do
Of course this is just one person's experience, others here will have more valuable input