The goal is to create an amp that extends the expressive capability of the guitar or bass. To do this the tubes are pushed very hard in order to create a smooth, gradual, musical transition to breakup.

This is quite noticeable on the guitar but it is easier to explain when talking about an electric bass. The bass sound that I like is one that is always right on the edge of mild breakup. This allows the bass to "growl" a bit when you lay into it with your right hand.

For a guitar it turns out that making the best clean sound is the same as making the best breakup sound. In other words, the guitar has to respond to overloads in a musical way even though what you are after is a clean sound.

A single 10" speaker is used in an acoustically unique cabinet.

Never measured it. Research discovered that watts are meaningless for what this amp is trying to do.