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Tommy,A few "newbie" questions for you!Do the ultrasonics that most tweeters can reproduce these days cause listening fatigue?Is most source material bandwidth limited?When Stereophile uses exotic rigs to shunt ultrasonics how should we think about that?What else should we know about ultrasonics?Seth
When it comes to AC power lines and EMI/RFI interference, the two go-to experts are Bill Whitlock and Jim Brown. Both have been the AES committee chair on EMI/RFI interference. Their many papers contain much better information & advice than typical internet ramblings.Bill Whitlock:2012 "An Overview of Audio System Grounding and Interfacing"http://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf2005 "UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS"AN007 Generic Student Seminar Handouthttp://www.jensen-transformers.com/application-notes/2010 "Ground Loops: The Rest of the Story"ABSTRACTThe mechanisms that enable so-called ground loops to cause well-known hum, buzz, and other audio systemnoise problems are well known. But what causes power-line related currents to flow in signal cables in the firstplace? This paper explains how magnetic induction in ordinary premises AC wiring creates the small voltagedifferences normally found among system ground connections, even if “isolated” or “technical” grounding isused. The theoretical basis is explored, experimental data shown, and an actual case history related. Littlehas been written about this “elephant in the room” topic in engineering literature and apparently none in thecontext of audio or video systems. It is shown that simply twisting L-N pairs in the premises wiring canprofoundly reduce system noise problems.http://xa.yimg.com/kq/groups/20963848/268252969/name/Whitlock-Fox+-+Ground+Loops+.pdf***********************************Jim Brown:"Power and Grounding For Audio and Audio/Video Systems -- A White Paper for the Real World"http://www.audiosystemsgroup.com/SurgeXPowerGround.pdf"RFI, Ferrites, and Common Mode Chokes For Hams"ignore the word Ham, as much of the paper also applies to audio systemshttp://www.audiosystemsgroup.com/RFI-Ham.pdfAbout 50 more good papers & Power Points.http://www.audiosystemsgroup.com/publish.htm
How many filter poles do your amplifiers use in the output filter and what is the corner frequency? Do you find that there is an audible consequence to a higher parts count in the output filter? Scotty