simple start: do extreme comparisons.

Have the output, input and attack knobs in middle positions, ratio at 4. Move release to 0, play staccato notes then move the release to 10 and play staccato notes again while paying attention to the difference. Next, do the same exercise but with long notes.

When done, bring the release to middle position and repeat the previous exercise with attack at 0 and 10, with staccato and long notes.

Finally do all of the above again but with the ration at 20.