Can a new amplifier affect speaker placement?

Hi all,

So I went out and got me a shiny new amp. One thing I'm certain I've noticed is the bass isn't as rich as with the old amp. The new amp is well-known for its bass response. The old one may have been too (don't remember) - but it's less than half the power and a fourth the cost of the new one. Both amps are overachievers in their price category. In short - I've trouble believing my little Creek 5350SE has bigger bass than my NAD M2. I wonder if something else is going on. Has anyone had to re-position their speakers, following a new amp purchase?