I read in !emc-pstc that Chris Maxwell <chris.maxw...@nettest.com> wrote (in <83d652574e7af740873674f9fc12dbaaf7e...@utexh1w2.gnnettest.com>) about 'Pro-audio and ground lifting', on Wed, 20 Mar 2002: >I have a feeling that >"hum" could be solved by power filtering without disconnecting grounds; >the ground removal is probably just an easy way out.
Power filtering is rarely the problem. The main cause of hum is circulating currents in signal and protective grounds. This is why disconnecting the protective ground 'cures' the problem. The correct way to cure it is to use balanced signal circuits, or at least balanced inputs. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk Interested in professional sound reinforcement and distribution? Then go to http://www.isce.org.uk PLEASE do NOT copy news posts to me by E-MAIL! ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
