I actually recently emailed Spencer to clarify, and he confirmed that it is a buffer. In my case, I think the output impedance was actually causing me to have problems with my fuzz pedals, because it also didn't occur to me that the III could be buffered.Wow, I never even noticed this fact until now. I just checked the manual and it says "transparent active bypass system with proprietary electronic switching". I've read the manual before but I wasn't even thinking about it, I was just sure that all 3Leaf pedals are true bypass. Interesting!