Let me add a little clarity on using the Apple TV box with a stereo system audio playback.
Do not use the audio output on the Apple TV box due to the poor d/a converter in the Apple TV box.
Connect the Apple box to the TV set via HDMI cable. Then in the TV set settings change the tv audio output to PCM stereo audio output. These gives a constant volume digital output via the fiber optic audio connector on the TV set. Run a fiber optic cable to a d/a converter then analog output from the d/a converter to the preamp.
Your preamp volume control is then the only volume adjustment. The remote control on the Apple TV box and the TV set remote control will not adjust the volume. Whatever is used dvd, cable, streamed movies, Amazon music, etc the preamp controls the volume.
This is the same with a ROKU streaming box.
Do not use the audio output on the Apple TV box due to the poor d/a converter in the Apple TV box.
Connect the Apple box to the TV set via HDMI cable. Then in the TV set settings change the tv audio output to PCM stereo audio output. These gives a constant volume digital output via the fiber optic audio connector on the TV set. Run a fiber optic cable to a d/a converter then analog output from the d/a converter to the preamp.
Your preamp volume control is then the only volume adjustment. The remote control on the Apple TV box and the TV set remote control will not adjust the volume. Whatever is used dvd, cable, streamed movies, Amazon music, etc the preamp controls the volume.
This is the same with a ROKU streaming box.