"controller" has no break. The lips never meet while pronouncing the word.
"ComPtroller" is more correct, but in practice, a little awkward, so the 'p' is nearly not pronounced at all.
Sound is more like "coMtroller", where the lips meet and there's an interruption to the open mouth sound. The 'p' in the word makes the interruption is just slightly more than if the word were spelled ... say ... 'comtroller'