What does a two band master volume knob do on a Hiwatt T40 ?

[deanllo]

I've been looking at buying my first tube amplifier and I've come to terms with how low they really are, so i need an amp that can be driven at a low volume level.

So my real question is, is a two band master volume knob the same as having a master volume know and a separate volume knob for a clean or driven section ?

[Firestorm]

It's odd that they don't say what it is or what it does. It isn't a separate master for clean and overdrive modes, though, which have separate drive controls. If I had to guess, they're likely using a pre-PI master and since this alters the source impedance feeding the PI, which in turn alters tone, it may be an attempt to compensate for that. No idea how it's implemented.