On Wed, April 1, 2015 5:46 am, Chris Caudle wrote: > On Tue, March 31, 2015 12:36 pm, Patrick Shirkey wrote: >> That person might not have much money but they might have the time to >> figure out where the buzz comes from and do something productive. Who >> knows they might even be able to provide useful feedback to Behringer >> that >> improves their Linux solutions. >> >> Sounds like everything else on the board was working ok so a little bit >> of >> hum should be relatively easy to solve. Maybe it just needs some contact >> spray. > > That type of problem is indicative of poor circuit reference conductor > routing (colloquially called "ground loop" or "pin 1 problem") and can > sometimes be improved with judicious use of added wire or copper foil tape > connections, but often requires a new and proper PCB layout to correct. > It is basically just sloppy layout work by the design team. > So you are saying that Behringer manufactured and released an entire range without testing *any* of them before they went out the door for ground loop issues at the board/design level? Seem pretty unlikely even for cheap low end manufacturing from China. they usually try to test at least *one* of their boards for obvious things like that before they mass produce. More likely this one just slipped through the (random) QC process which tends to happen when you have a tight deadline and many thousands of units to ship and some low paid unskilled workers manning the production line... I'm sure that someone from the LAC would be more than happy to test it for Fons and help get to the bottom of the problem. >From his description it sounded like the device was working pretty good with Linux in every other way. Just a bit of hum at the hardware level. That is not bad considering that only a few years ago the idea of an affordable plug and play digital hardware mixer on Linux was just that, an idea. -- Patrick Shirkey Boost Hardware Ltd _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user