The Mad Professor Blueberry is a bass overdrive that is based around the BJF Honeybee circuit. Lohstah over at the freestompboxes forum decided to trace one and this is what he found;
Check out the Mad Professor page for more info or have a look at this youtube video;
There is a full PCB layout here, in the freestompboxes thread;
http://freestompboxes.org/viewtopic.php?f=7&t=12986