So I used musnix to set everything up:

  sound.enable = false;
  hardware.pulseaudio.enable = false;
  security.rtkit.enable = true;

  services = {
    pipewire = {
      enable = true;
      audio.enable = true;
      alsa.enable = true;
      alsa.support32Bit = true;
      pulse.enable = true;
      jack.enable = true;
      socketActivation = true;
    };

  musnix = {
    enable = true;
    ffado.enable = true;
    soundcardPciId = "08:00.0";
    kernel.realtime = true;
    rtirq = {
      resetAll = 1;
      prioLow = 0;
      enable = true;
      nameList = "rtc0 firewire_ohci";
    };
  };

  users.users.wonko = {
    isNormalUser = true;
    description = "Brian Hechinger";
    shell = pkgs.zsh;
    extraGroups = [
      "wheel"
      "audio"
      "libvirtd"
      "users"
      "docker"
      "kvm"
      "wireshark"
      "onepassword"
      "onepassword-cli"
      "qemu-libvirtd"
    ];
  };