The buffered mult will take a signal (audio or cv) and dispatch it without loss to 1 to 4 destinations. For example you could send the sine wave from a pamela channel to modulate Marbles Deja Vu and Rings Damping.
VCA control amplitude of a signal (audio or cv) thru a modulation source and you definitely need more than one. I suggest a quad mixing/cascading VCA like the intelligel Quad or MI Veils.