Latest iteration of my freebsd hifi listening setup. Thinkpad X220 running FreeBSD 14.4-RELEASE, X11 + windowmaker, with Wolfson WM8740 DAC/PSU and SMSL PO100 usb spdif interfacef/re-clocker, on top of an HD8-A1 class-A headphone amplifier, with Beyerdynamic DT-990 PRO headphones. As shown, streaming the lofi girl channel using mpv, I also have mpd configured. Admittedly the audio electronics is starting to get a little bit out of control

, I really need to work out how to move the dac and amp off the table top. It sounds gorgeous though, the best sound quality I've heard so far. I have also tested this setup with my Quad 77 amp and Tannoy speakers, it sounds very nice, especially playing .flac's with mpd. The PO100 will support DSD / DOP64, but I have not tried that yet, nor configured for bitperfect with this setup. I am using base OSS with nothing on top (no pulseaudio, pipewire etc). Perhaps I need a separate small stand to put the audio gear on, or add a shelf underneath.
Detail of audio cabling. If this keeps growing I may invest in a local mains plugbar to reduce the number of trailing mains cables. Though I think this is probably going to be it for a while now.
I've made some more detailed notes on the audio equipment used in this photo, in the dac thread starting here
https://forums.freebsd.org/threads/is-there-any-dac-compatible-with-freebsd.74463/page-4#post-760444
I have added the following two settings in /etc/sysctl.conf, as documented in the sound(4) manpage.
# auto-configure default usb soundcard
hw.snd.default_auto=2
# better sound quality
hw.snd.feeder_rate_quality=4