After reading the responses, I'm going to look into these caps. Elizabeths comments on how the video images improved goes great lengths to show that though our ears may play tricks on us, our "lying eyes" can discern things more easily and is repeatable.
If video images improve with these, then there has to be something going on with these RCA inputs acting as conduits, of sorts, to some kind of interference which play havoc with the sound.
All the best,
Nonois