The word `enough’ suggests sufficient or adequate. For example, when you say that you had enough chairs for the guests, it means that you had sufficient number of chairs for people to sit on. The chairs met your requirements; they were adequate.
When you say that you had ample money to go on the trip, it suggests you had more than enough money. Ample is larger in degree and quantity when compared to `enough’. If you have ample evidence to put a guilty man away, you have more than adequate or sufficient evidence to put him away for good. In other words, you have plenty of evidence.