On Wed, 3 Jun 2015 23:21:43 -0700 (PDT), Len Ovens wrote: >I don't know about ground switch, but some of them had a "hum" switch >or something similar... flipped the ac lines. Sometimes the "neutral" >was connected to chassis... which with no keying on the ac plug meant >the chassis might just as easy be hot. Nobody has done that for a long >time now. The idea was old and outdated 50 years ago. (probably before) I also think it might soft or more likely hard disconnect neutral (case ground) from audio cable connectors ground. Again, I want to point out, that proper ground wired equipment still could cause issues, when the microphones ground source from the outlet is another ground source from the outlet for the guitar amp. On Wed, 03 Jun 2015 22:23:59 -0700, David Christensen wrote: >If this is a home studio fed from the same panelboard that feeds your >house, you might find that all the other loads in your house (and/or >your neighbors' houses) are causing electrical noise problems for your >audio systems. As long as electric arcs or heavy machinery aren't involved, but just averaged home appliance it doesn't matter. Even a broken washer, illegal baby alarm and 10 cheap switching power supplies unlikely will cause audible issues. Indeed, even a single bad designed electric clock in the neighbour house could cause radiointerference. In Western civilisation detector vans seize such broken clocks. If you're living close to a street railway or the like, than you're screwed. Btw. we should avoid spaghetti syndrome, but even a spaghetti syndrome that is a mix of audio cables and main cables unlikely cause an audible issue. > For example, separating power and signal conductors as widely as > possible ... ... doesn't harm, but if the distance is the length of even a long room, a few centimeters or a meter should be enough. Audio engineers not seldom use mains and audio cables in parallel, close together over distances that are much longer than long rooms. Just the audiophiles tend to care about separating centimeters of cable. Nothing should be broken, IOW audio gear and lighting should be without flaws and your neighbours shouldn't make steel, that is more important than separating audio and mains cables "as widely as possible". _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user