I only use the SPDIF input on my 2.1 amp. After each time it is powered off and back on, it resets to another input. This requires me to select AUX IN as input and then OPT IN before audio starts working.
Is there an option for the amp to remember its last input selected? It appears to remember all the other configurations on the amp, thankfully e.g. Treble, bass, d.bass, X-over, etc.