inflames wrote
Just a question, this has to be a valve amp right?
I have never seen high/low inputs on a solid state amp before.
Imho with a guitar amp design you want to go into the first tube with as little components in the signal path as possible. In fact, you want this all over the amp: stick to the minimum. This is a consideration that does not seem to be preached a lot in solid state classes around the world. The other thing is that solid state amps rarely are top-of-the-line, no-expenses-spared things. The cheapest way is to first put the guitar signal into a nice pot, only amplifying the miserable little excuse for a signal that comes out of there. So that is what they go for and that does not need hi/lo input.
inflames wrote
Some amps also has a build in attenuator on the low input
The idea is that if the guitar has active pups or the signal comes through a hot pedal, it is beefy enough to first go into a pot.
