I have been studying the schematic of the Tubescreamer TS-808. On the schematic, however, I have found a few places resistors connected on 1 side, and on the other side, it says "Vb". Heres the schematic: http://www.tonepad.com/getFile.asp?id=81 . Can someone please help me and tell me what that is, or what those resistors are connected to? Pink_Queen, Seljer, Greenbox, im sure you all can help me.

Thanks guys.