I just made a fresh install of Hifiberry OS on my Raspberry pi 4, I installed first on the Raspberry pi, then turned it off, then plugged the Amp 100 with DSP, then restarted. After restart I played Spotify on my mac and channeled the sound to the Amp 100 via Airplay, and the speakers made a really horrible noise, high pitch.
It happened already yesterday as I was doing some tests with DSP and optical in.
My DSP program is V.11, the default one that came in with the fresh install.
Now I'm a bit concerned to start the hifiberry again, because I really don't want to break my speakers with this sound. What do you recommend me to do?