Buying an amp based on what you hear on Vandy 5A speakers when you intend to buy Vandy 3A speakers is a mistake.
The 5A and the 3A Signature do not offer a useful comparison since the 5A speakers have their own powered subwoofers and the 3A speakers do not.
The 5A and the 3A Signature do not offer a useful comparison since the 5A speakers have their own powered subwoofers and the 3A speakers do not.

