Variac for guitar amp full#

I know that 100 watt Marshalls have this cavernous, room-filling sound even without running at extreme volumes.

The only thing is that I worry that by using a variac on a 100 watter it might make it sound a little smaller in the low end. I wouldn't be running an amp that brown, but say I had a Super Bass running ~460 volts on the plates and I cranked down the voltage with a variac down so that it ran around 330-350 volts on the plates, would I be lowering headroom/volume significantly that I could use the amp at large clubs and outdoor venues? I assume I could get a 50 watt Plexi running fairly quiet (relative term- quiet for me is not what most people consider quiet) if I used a variac. I would love to crank a Super Bass to 5 or 6 at medium to large venues though. I know wattage is obviously not linear to volume, but it seems like a variac might be a cool alternative to an attenuator if I DON'T need whisper quiet volumes. He also mentioned it was running at roughly 35 watts. I am not an EVH brown sound fan at all, but I stumbled upon a video of Mike Soldano talking about how EVH's 100 watt Plexi was fairly easy to crank up and got nice natural compression when the voltage was down to about 90 (I think he said about 300-310v on the plates). By doing this, they are putting less plate voltage on the power tubes, and create a 'browner' more compressed sound, while also lowering the volume to some extent as well, correct?

Variac for guitar amp full#

Variacs essentially lower the voltage of an amp, thus the power transformer doesn't receive/produce enough B+ to provide full power.