Vintage Amp Hookup question

I have an old Sansui AU-717 Integrated amp (that I bought new when I was 18 years old). I need to hook up two analog sources. One is our digital television receiver (with about 20 music channels). It has an internal D/A converter with analog outputs. I have it plugged into the AUX input and all works and sounds fine. For the CD player, I tried the Tuner input, but not enough gain (very quiet). I tried a phono input and...way too much gain. So, I tried a tape input and it seems to work and sound fine, although the amp seems to get a bit warmer when operating. Will it damage anything to run the CD source analog outputs into the tape loop on the amp? Since there's only one Aux input I don't have many options.

One other thought. Would it be better to run two splitters so that I can plug both sources into the same Aux input?

Thanks for your help.
Using the tape input is fine.I am puzzled why the tuner input didn`t work.They are both line inputs.Don`t use that phono input,only for phono!That gain was do to the Built in phono preamp In your Sansui...As for the heat just make sure the amp is well ventilated.Don`t set any thing on top of it.Just remember the age, don`t crank the volume to high.