Didn't read any above posts. From a pure understanding of physics, No. No need to impede voltage or amperage = power to a power amp ever! Filter your source. Not your power. Your source gets amplified, which amplifies the noise! All good power amps have noise reduction by design. In fact, your power amp was designed to function on the typical impedance of your ac mains. How can another circuit in from of that improve your AC feed. ANY other circuit in front of your amp will increase impedance. It is impossible that it can reduce impedance based on physics, Come on Man, really? You ask this question? Don't be daft my friend. I'm not British but I watch British TV. Those who place a power supply "conditioner" in front of their power amps likely a. never studied physics in college, b. never passed physics in college or c. never went to college or cared to understand physics. Sorry if this offends anyone, but this is my truth. Peace.