Dual Mono Tube Pre-Amps

I have tube mono-bloc amps and was considering changing out my pre-amp to a dual mono tube pre-amp. On paper it makes sense but is there really much of an audible difference? Also any suggestions for the pre-amp?

I have a set of Tom Tutay updated Altec 1570b mono-bloc amps directed by an Air Tight ATC-3 pre-amp.

Thanks