The Tweed Deluxe (formerly known as the Aurora Dual Drive)! The boost side is the Northern Lights, which is a modified treble boost so it can be a treble, mid or full range boost. The drive side is based on the Tweed Drive, but has been adjusted to have a bit more headroom as well as some eq adjustments. There is also an order switch so than you can have the drive going into the boost for a more traditional volume boost for soloing, or running the boost into the Tweed Drive to push it into higher gain. This in my opinion is where the magic is.