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.
I never knew this was a thing until I saw a forum post about it this week. Apparently it is the anti-boost, which means that the output can only be attenuated. Sounds easy enough… a potentiometer and switch in a box will do the job but can lead to loading problems and tone loss, so I quickly designed this circuit:
I have a paper copy of the 1st edition of the CMOS Cookbook that I used so often that the pages started to come loose from the binding. It is an essential resource for anyone who wants to work with CMOS chips.
The author, Don Lancaster, has made the 4th edition of CMOS Cookbook available for free download from his site. Get it immediately. Thanks Don!
Another free download, this time from Hans Camenzin who invented the 555 timer chip! The book is called Designing Analog Chips and is available as a free download from the author.