I would like to share my experience with UNDERclocked Raspberry Pi 4 model B (RPi4B).
My setup is Audirvana (MacBook Pro 15", mid 2015) => wifi-stream (UPnP) => RPi4B (with Geekworm Raspberry Pi 4 Case) => HiFiBerry DAC+ DSP => Optical cable (Audioquest Forest) => Fostex HP-A4BL.
First, I had a problem that
moOde 7.0.0 did not respond after using it for about 2 hours, and I also heard hiss noise between tracks. I thought it was because
moOde 7.0.0 was just recently released at the time of writing. It might not stable. Then, I switched to
HifiberryOS as Hifiberry recommended, but the problem still existed. At the time, I was playing with overclocking another RPi4B, so I thought about underclocking this RPi4B. I followed Archimago's
MUSINGS: Raspberry Pi 3 B+ CRAAP Settings and raspberrypi.org's
Overclocking options in config.txt
Here is my tweek in config.txt on
moOde 7.0.0.
over_voltage=-4
arm_freq=1000
gpu_freq=250
max_usb_current=0
My system now runs smoothly overnight without any crashes/hangs. The CPU temperature is 44 - 47°C (
watch -n 1 vcgencmd measure_clock arm). I still hear hiss noise between tracks but at a lower level. You may follow my tweek. If your system crashes/hangs, you can increase each parameter a little. Enjoy!