The SD45 is an extremely versitile amp despite it's vintage modern vibe. KT66 tubes are the at it's heart. They come stock with Groove Tubes, I swapped them for Gold Lions. 45 watts doesn't sound like much in the era of modern 100-200 watt tube amps. However this amp is as loud as any Mesa I've ever played. The aluminum chasis keeps the weight down. Has a switchable solid state/tube rectifier circuit, shared EQ for it's two channels, a loop, line out, ohm selector, 2 push/pull pots, and only six knobs. The EQ being shared is actually awesome. Kinda like the set it and forget it infomercials... The crunch works as an extention of your clean tone. The clean channel goes from clean to voxy to plexi. Drive goes from plexi to modded Marshall/Mark IV territory. The bright pull switch located on the drive knob only effects the cleans and adds chime to an already bright amp. The mid scoop only affects the crunch channel. It actually makes the amp go from a narrower frequency response to a modern hi-fi extended treble and bass response. It seems to add a little more aggression to the gain circuit too. Tonewise this thing is extremely articulate and isn't for inexperienced players. Everyone will know if you screw up. I doesn't hide anything. This is also great in that you guitar and bone tone will shine through. Budda has a reputation for quality and I've been given no reason to question it. This is by far the most fun amp I've ever played.