Hi, I'm sticking this post in traditional power but I have a question regarding AAC (Advanced Analog Control). It's claimed to be similar to DCC but using straight DC. I ordered but haven't used the QSI Quantum Engineer. It's a controller connected between the power supply and the track. I am going to use it with my two GP40's equipped with QSI Aristo sound decoder's. It is supposed to allow the user to operate many DCC type functions like horn, bell, sound volume, lights, etc previously unavailable to anyone using straight DC. I think it's a very interesting unit and can't wait to try it out. Has anyone used this?