The transistors are fairly irrelavent in the power boost i think, my reissue uses different transistors (BC182L i think) and i've built 2 clones using BC109 and they all sound pretty much identical, they are nothing like a boosted low gain fuzz face, so i'd disagree with you on that one.The Power Boost/Sound Overdriver typically uses silicon bc108/109 transistors. The same kind used in silicon fuzzfaces. But this thing has a tonne of output. So, a low gain fuzz face boosted would get you in a similar tonal area. The screwdriver uses mosfet (bs170 - the same type used in the SHO), a BC109 and an AC127 Germanium tranny. I would hazard a gues that using the Screwdriver at a high volume setting with low gain could get you some pleasing results.