vacuum tubes or optic bridges in audio equipment, if set up right, allows sound to saturate without clipping, which is where that "warmer" aspect comes from, this generates more pleasing upper harmonics instead of just crapping out (which most digital things will do if clipping), that's the reason you see tubes in expensive gear... sorta... the problem that makes it mostly "Baloney" is that the audio output of anything digital shouldn't reach that saturation point anyway, and if it does, it's only because someone is deliberately pre-amping it into the clipping range. So what that means is someone goes out of their way to make the sound worse, but in the slightly more pleasing way

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back to the OP: if there are better contacts, I could understand getting better performance out of the battery, but since it's all going
through a regulated circuit, I have a little trouble understanding how that'd be the case. All I can imagine is perhaps getting a bit more battery life.