I definitely noticed a huge difference when I changed to my MXR ISO brick. My signal chain of: Dunlop mini volume pedal, boss OC2, boss PS5, dark glass duality, iron ether frantabit, soundblox envelope filter, tc electronic sky surfer reverb, tc electronic nova repeater, Aguilar tone hammer, and ditto. Given the fact that the tone hammer needs 18V, and all the other pedals take different current draws, the mxr not only eliminated some ground hum I was getting, I also got better results from each of my pedals because they were actually getting exactly the current they needed. I can't recommend a good psu highly enough