I recently changed amps. Previously, I was running a Thunderfunk 550B. Now I am running a Genz-Benz ShuttleMax 9.2. (Both are through a Fearful 15/6.) I wasn't too surprized that my pedals did not sound the same through the GB. But I was surprized just how much the sound changed. For example, my Catalinbread SFT sounded great through the TF. It was a nice creamy, tuby overdrive sound as you would expect. Through the GB is sounded boxy and muffled. I really wasn't expecting that at all. So I started looking at my small collection of overdrive pedals again. My Blackbox X-Ray bass overdrive, which never sounded that good on with any previous amp, sounds fantastic through the GB. It has a grittiness that is very similar to my Dredgetone Angler, but with the much emphasis in a much lower range. (The DA continues to rule for nasty, upper-mid forward grit and bite.) The Prunes and Custard which keep moving on and off my board never sounded better. (It may actually stay this time!) I am glad I hung onto these pedals. You never know when they are going to be just the thing you need.