How to hook up monoblocks amp to single mono spkr

Dear all,
I am thinking to set up a mono playback using my mono cartridge, ss preamp, and mono block ss power amp. But I want to use one speaker only (hence pure mono).

I need advice on how to hook up one speaker to my mono block? Should I connect the speaker to both of red and black speaker cable (1side) to one of my mono block only? Or 1side of red speaker cable to one monoblock and black speaker cable (same side) to the other monoblock?

If first scenario, should I still turn on both monoblocks? As left And right interconnect from preamp go to both monoblocks.

Thanks in advance for any advice