On Samstag, 23. Januar 2021 18:52:50 CET Per Jessen wrote: > Per Jessen wrote: > > I have hooked up a headset to my Nanopi Neo Air, but the microphone > > quality is severely impacted by electrical hum. I have tested it and > > determined it is due to a power supply with no ground, i.e. the > > typical 5VDC 2A with a two-prong Europlug. Using one of those small > > power supplies in metal cabinets, with a ground wire, and the hum is > > gone. > > > > The latter is not really an option, so what do people do instead? > > I have discussed it on EE stackexchange, and there is no doubt it is a > ground loop (Brummschleife) issue
There is no doubt this explanation is utterly wrong. You can't have a ground loop without (multiple!) ground connections. There are other possible explanations: - badly shielded cables - conducted noise from some other part of the equipment, e.g. monitor, external amplifiers (AV Receiver), ... - bad (unsufficient) power supply You should try disconnecting all external equipment save the headset and then verify the noise persists. Kind regards, Stefan -- Stefan Brüns / Bergstraße 21 / 52062 Aachen phone: +49 241 53809034 mobile: +49 151 50412019
