Many so called 'all tube' amps have a solid state rectifier. Oh well, as long as it sounds good.
yeah, most modern, high gain all-tube amps have ss rectification. things like vox ac30's have tube rectos...
And, yeah, feline, i think doubling the volume means (approximately) multiplying the wattage by 10.
EDIT: my savage se has a half power switch (switches from pentode to triode operation), and it's definitely not "twice" as loud in full power mode- it's "perceptibly" louder...