Hi sir JojoD818,
When engaging the CD/Tape to Ctrl button, Do I have to move the source connection from line 3/4 to CD/Tape In? or just leave the source connected to line 3/4?
Yes sir, you need to use the CD/Tape In for connecting your videoke source.
I'm not 100% certain it will work, but I did read the manual for the 1202 and though it is vaguely described how to use the CD/Tape option it's worth to try.
Other larger mixers have programmable/assignable post-fader options, let's hope we can use this idea to route only the source to one of your amps.
On the other hand, what you have now using a y-splitter works just as good, the only problem is you need to adjust two volume controls. My only worry is phase inversion during the processes but since this is only for videoke purposes (I don't mean to derogate) you may get away with it as it is.
Try lang, kaunting oras lang naman mawawala. That way you can fully understand the capabilities, as well as the limitations of your 1202.
Cheers