For the video setup guide, follow the video here
You will need:
A40 Headset
MixAmp Pro
MixAmp USB Power Cable, Optical Cable, and Inline mute cable.
First, ensure the MixAmp Pro has the most recent firmware installed. Ensure the MixAmp is connected to the USB Port on your PC in order to update it on your PC.
Connect the MixAmp Pro to your PS4. Insert the MixAmp USB Power cable to the front USB Port and connect the Optical cable to the MixAmp USB port and PS4 optical connection located on the rear.
Next turn on your PS4 and wait for it to load to the home screen.
Go into the "Settings" tab on your top bar of your PS4 home screen. Go to -->"Settings" -->"Sound and Screen"--> "Audio Output Settings"-->"Primary Output Port"-->"Digital Out(optical)"--> then check Dolby Digital 5.1 ch then hit OK.
Under the "Audio Output Settings" menu select "Output to Headphones" and make sure "Chat Audio" is selected and not "All Audio".
Also under the "Audio Output Settings" menu select "Audio Format (priority)" and make sure "Bitstream (Dolby)" is selected and not "Linear PCM"
Connect your A40’s to your MixAmp by plugging the Inline mute cable into the headset, and the other end of the cable into the port on the MixAmp with the headset icon.
You are now ready to use your A40’s on the PS4.