My third music stream is a Pi 3B+ with ADC Pro and AAmp60. Power supply is Hifiberry 20V 4amp. Very happy with it. I can run my turntable in the analogue input and power a vintage set of Wharfdales'. Very happy with HifiberryOS too. Nice System.
I have been noticing an annoying noise from speakers like a mosquito buzzing when all else is quiet. It is still there when system is powered down. Only stops when power supply is physically disconnected. Just wondering if there is and work around for this?