The Booster 2.5 was one of my early amp-in-a-box designs from about 1999. It has been used on numerous commercial pedal designs and as a starting point for the BSIAB and other similar designs.
The Tweed Stack is my own improvement on the Booster 2.5 and at this time there are a couple of pc boards still available for it.
Here is a demo sound of the Booster 2.5 played by my good friend Aron Nelson, who runs/owns the DIYstompboxes forum:
