thought I'd chime in... there was some discussion about using one as an on-board guitar booster. I did one up just for that purpose....having some trouble with it though. I think I fried the BS170...typical. I've heard you can't even touch the legs... I'm not sure how to wire one up without frying it. Mine works with the pot all the way DOWN, but if you turn it up it cuts out. Anyway, here's my layout and actual pic of it installed. I just desoldered the leads going to the output jack and stuck the circuit in there. It sounds good! And RL actual pic: hope this helps or inspires someone.