The phase button on my Rowland Capri is for...?

Did he put it there to drive me nuts? On some songs, turning on the phase button sounds better, other songs worse, and others no difference. And the differences between all 3 are extremely subtle. Maybe a slightly wider stage, maybe a little more bass...or the inverse. Or nothing.

I am running a Benchmark DAC1 via balanced outs to the balanced ins on the Capri preamp, and balanced outs from the Capri to the balanced ins of my Rowland 102 amp.

I have read that Rowland uses the "old" method of balancing...whatever that means. I have also read that the Benchmark DAC1 is not "differentially" balanced.

I have no idea what any of this means. But I do find it somewhat irksome that pressing the phase button is so unpredictable.

Could anyone please explain briefly, in Best Buy terms, what all this means, and if the Benchmark is in fact playing nicely with my Rowland gear? The sound is pretty phoenomenal regardless. I'm more curious than concerned. In my crazy brain, seeing the orange light on the phase button makes me feel like I'm not listening to the sound in the purest form, like seeing a bass/treble knob not zeroed.

Thanks in advance for any shed light!