Back when phono was my only source I deliberately connected one cartridge channel backwards, so that it was out of phase. Since most of the signal is common mode in the two channels (mono) this eases the load on the power supply of the power amp. When one channel pulls positive current the other is pulling negative. Of course one set of speaker wires needs to be reversed to get the audio back into phase. An added feature of this scheme is that a center speaker can be connected bridged across the stereo amp. A pot connected between the two channel signals at line level allows the volume of the center speaker to be reduced. Although this puts a low impedance load on the power amp, I never had any problem.
If you hook up your system this way, other source components, eg: tuner, need to be similarly phased, and it becomes a can of worms. For pure phono though, it works great.
If you hook up your system this way, other source components, eg: tuner, need to be similarly phased, and it becomes a can of worms. For pure phono though, it works great.