I have been experimenting since I got my Klon well over a year ago. I have been through quite a few OD's and so far to date, I'm the happiest with the Box Of Rock feeding the Klon feeding my Heritage Colonial w/el34's. I'm using the BOR as a solo boost into the Klon, and the Klon as my low gain crunch and fattening tool. Settings that seem to work the best right now (things always change) has the BOR gain at about 10-12 o'clock and the tone at 1-2 o'clock. Klon's gain is anywhere from noon to 3 o'clock and tone is at noon to 2 o'clock...once again depending on the venue and my ears etc. Others that quite did not make it as well with the Klon were some great pedals, but so far for my playing and the tone I'm looking for, nothing has beat this combo yet...Key word Yet ...gotta love G.A.S.