a little bit, im not sure how to cure it either, its about as bad as the pop when the unit goes on and off, minimal.
i stole the idea off a picture i saw somwhere :S
<edit>
saw this and it gave me the idea to try it
http://www.chambonino.com/construct/const12k.jpg
from this page
http://www.chambonino.com/construct/const12.html
triple transistor switching is mentioned there, i dunno how that would be possible without more switches (could have 2 switches with 2 transistors attached and then a switch to select between them).
i would like to add a mid boost switch to mine, ive already ordered a few more bits to make another one and use my other transistors up, i think even the nasty sounding ones would sound better if i biased them properly with a trimmer.